公告版位

铌的用途 铌作为铁基、镍基和锆基超级合金的添加剂,可提高其强度性能。中国有色网。 铌在原子能工业中适于作反应堆的结构材料和核燃料的包套材料以及航空、宇航工业中热防护和结构材料。中国有色网。铌电容和钽电容相似,但由于铌的密度小, 单位体积电容量则较大。中国有色网。铌钛、铌锆合金及铌锡、铌铝锗等化合物超导材料,除用作输电、发电、制造超导磁体、控制核聚变外,还用于宇宙飞行器中 的导航装置、高速潜水船只的电磁推进设备以及超导超阶级高速列车等。中国有色网。铌耐酸腐蚀性能比锆好,不如钽,可作热交换器、冷凝器、过滤器、搅拌器 等。中国有色网。碳化铌可以单独使用或与碳化钨、碳化钼配合使用,作热锻模、切削工具、喷气发动机涡轮叶片,阀门、尾裙及火箭喷嘴涂层。中国有色网。含铌 的合金钢强度高、韧性好、抗冷淬,广泛用在输油管道。中国有色网。铌酸锂单晶用于彩色电视机。中国有色网。 铌的性质 铌是一个种显钢灰色光泽的难熔稀有金属,其熔点为2467。中国有色网。C,密度为8.6克/厘米3。中国有色网。铌具有良好的低温塑性,可冷压力加工成 各种半成品。中国有色网。耐高温、强度大,在1000。中国有色网。C以上仍具有足够的强度、塑性和导热性。中国有色网。在极低的温度下超导性最好,如在 零下260。中国有色网。C左右其电阻接近于零。中国有色网。在150。中国有色网。C以下抗化学腐蚀和大气腐蚀。中国有色网。在常温下对许多酸和盐的溶 液都是稳定的,但溶于氢脆。中国有色网。阳极化时生成稳定的氧化膜。中国有色网。在自然界矿物中铌。中国有色网。阳极化时生成稳定的氧化膜。中国有色网。 在自然界矿物中铌、钽共生,含铌、钽的矿物有:烧绿石、铌钽铁矿、褐钇铌矿、含铌钛铁金红石、红晶石以及含铌钽酸盐的砂矿。中国有色网。某些炼钢炉渣和炼 锡炉渣也是是、提练铌的重要资源。中国有色网。划分铌矿或钽矿,主要是根据矿物中含铌或钽的多少而定。中国有色网。 铌三锡超导磁性能达到国际水平 宝鸡稀有色金属加工研究院用自产线材试制成功内径为23.5毫米的插入型多芯铌三锡超导磁体。中国有色网。这种磁体与常规磁体比体积小、重量轻,磁场强度 高;若通电闭合运行后,则长期运行不需供电。中国有色网。经中法两国科技人员在法国国家科研中心高场实验室一起测试,在-286.96℃下,磁体中心场强 达15.4万高斯,性能达到国际水平。中国有色网。

中国有色网

 

责任编辑:CNMN

 

 

引用出處: 

http://www.cnmn.com.cn/ShowNews.aspx?id=9184

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!  

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com/ / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drillTapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer.

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。   

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

 

beeway 發表在 痞客邦 留言(0) 人氣()

鈮是一種化學元素,它的化學符號是Nb,它的原子序數是41,英文 名稱為 Niobium為過渡元素第5族,即VB族。高溫下,鈮會跟絕大多數非金屬單質反應:室溫即與氟單質反應,200 °C即與氯氣和氫氣反應,400 °C與氮氣反應,產物通常是填隙式且不是整比化合物。鈮置於空氣中200 °C開始被氧化,卻能夠抵抗熔融鹼金屬和酸(包括王水、鹽酸、硫酸、硝酸和磷酸等)的腐蝕。鈮能被熱的,濃的無機酸腐蝕,包括氫氟酸或氫氟酸/硝酸混合 酸。儘管鈮能顯示出所有正常的氧化態(從+5到?1),其最穩定的價態為+5價。

鈮能夠形成+5價氧化物五氧化二鈮(Nb2O5),+4 價的二氧化鈮(NbO2)還有+3價的三氧化二鈮(Nb2O3)和較為罕見的氧化態+2價的一氧化鈮(NbO)。最穩定的氧化態為+5,五氧化物跟非整比 的二氧化物是最常見的鈮氧化物。鈮的五氧化物主要用於生產電容器,光學玻璃,或作為製備鈮的其他化合物的起始材料。製備這些化合物,我們可以將其五氧化二 物溶解在鹼性氫氧化物溶液中,或是將之與其他金屬的氧化物共同熔融。例如製備鈮酸鋰(LiNbO3)、鈮酸鑭(LaNbO4)。對於鈮酸鋰的結構,鈮酸根 離子(NbO3)不是作為單體存在,而是三角形扭曲的鈣鈦礦結構的一部分,而對於鈮酸鑭的結構則包含孤立的NbO4?離子。鈮酸鋰作為一種鐵電物質,被廣 泛應用於手機和光調製器,以及聲表面波器件的生產,屬於ABO3結構類似鉭酸鋰和鉭酸鋇的鐵電體。

鈮能夠形成+5,+4,+3價鹵化物 (NbX5,NbX4和NbX3),也能生成多核配合物和非整比化合物。五氟化鈮(NbF5)為白色固體,熔點79.0 °C;五氯化鈮(NbCl5)是黃白色固體,熔點203.4 °C。兩者都能發生水解反應,在高溫條件下能夠與過量的鈮單質反應,生成黑色極易潮解的四氟化鈮(NbF4)和四氯化鈮(NbCl4)。鈮的三鹵化物能夠 通過氫氣還原其五鹵化物製得,而其二鹵化物則不存在。高溫下一氯化鈮的光譜能夠被檢測到。鈮的氟化物可用於分離鈮和鉭的混合物。五氯化鈮在有機化學中被用 作觸發烯烴的Diels-Alder反應的Lewis酸。五氯化鈮還能作為原料製備有機金屬化合物二氯二茂鈮((C5H5)2NbCl2),可作為製備其 它有機鈮化合物的起始原料。其他二元化合物如氮化鈮(NbN)在低溫條件下顯示出超導性,現已用於紅外探測器;碳化鈮則是一種硬度很大的,熔點很高的陶瓷 材料,在製造商品上用於製造切割工具的一部分。鍺化鈮(Nb3Ge),錫化鈮(Nb3Sn)還有鈮鈦合金,都被用作超導磁體的超導導線。

貳、    Crystal-Lattice Collapse Method簡介

從 標準碘化學蒸氣運輸法,即由NbSe2 (Alfa-Aesar 99.8%),碘(AG Fluka)以及活性碳(Fluka)的工業用粉末製成重量比約10:10:1的混合物,並將其混合物合成Nb mesowires。並將Nb mesowires放入一個乾淨且真空封閉(1.5*10^-5torr)的石英管中(直徑10mm,長120mm),之後,將石英管放置在水平管狀電熔 爐的中央高溫區域,當熔爐溫度梯度達到10 °C/cm,室溫緩緩加熱(加熱速率為4 °C/min)到830°C,隨後ampule會慢慢自熔爐被生成出來。

在過程中,活性碳的加入,可避免由環境所造成的氧化。在晶體成長完後,大部份在被排出的石英ampule的氣體(如典、矽),被放置於ampule的內壁由室溫快速的冷卻。

 



參、分析

 



一、SEM
此圖是利用掃描電子顯微鏡(SEM)由高溫區域收集的灰色樣品圖像。這些1維的 mesowires 均有相似的直徑和60-100微米的長度,且為管狀結構。

 



二、EDAX
此圖顯示由化學元素分析的x光光譜能量散佈分析(EDAX)結果。光譜表示單一個,mesowire的合成,物主要包含Nb,和少量氧氣。銅金屬的部分可能是Nb管外面的銅金屬,而非管內之雜質。

 



三、SAED
此圖顯示選區電子繞射(SAED)的結果,表示出他是一個體心立方堆積結構(bcc)縱向邊緣顯示出一個無缺陷的結構。相鄰的晶格平面約 3.6 A。而且,Nb 導線似乎有特定的平面。

 

 



四、MPMS
此圖可了解我們的產物和純的Nb元素的差異,其中差異可能是產物中帶有Nb的其他化合物結構所產生的雜質。

NbSe2(黑線)
純的Nb元素 (藍線)    group 16_fig5
成品(紅線)

五、Pxrd
A:一開始的材料 (NbSe2)
B:高溫區的成品 (Nb+雜)
C:低溫區凝結物 (Se)
此階段的分析證明部分Se已從一開始的材料中消失。而產物部分則帶有雜質,恰好和MPMS的檢驗結果有所呼應,產物的Nb金屬其純度不是100%。

 



肆、Crystal-Lattice Collapse Method 原理

 


在184.3度時碘化成氣態,體積較小的碘原子擊穿了體積比較大的Nb化合物晶格。由於該化合物的曾跟層之間是為弱的凡得瓦力所以很輕易的就被破壞了。

 


在221度時,晶格內的Se原子開始液化,並和碘原子產生互擴散作用,加速了碘原子在晶格內的擴散速度。
在830度時,晶格內的Se原子開始轉為氣相,並和碘原子一起離開了晶格,並在低溫區重新凝結形成元素Se。

 


當Se離開晶格後,為了使表面能量最小化,剩下的Nb的柱狀結構開始重新形成Nb的奈米管狀結構物,及奈米Nb管。

伍、應用
一、化合物元素分離
由於有些元素活性很大,在大部分時間下會以化合物的型式存在大自然界中,為了要得到純的元素,可以利用此方法讓化合物裡的元素們分離,而此法之條件在於化合物裡的元素們之熔點彼此相差要非常大,才能利用此方法。

二、奈米金屬管
由於此方法亦可用於製造奈米金屬管,故舉一些奈米金屬管之應用。

二氧化鈦(TiO2)奈米管:
醫用植體(medical implant)如支架及義肢常會引起人體發炎反應,但美國加州大學舊金山分校(UCSF)及賓州大學的研究人員最近發現,如果植體是以二氧化鈦奈米管製成,發炎的風險將會大幅降低。

心血管植體容易導致發炎反應,造成血管壁的細胞增生並附著在植體表面,例如再狹症(restenosis)是包圍內皮層的血管平滑肌細胞(VSMC)增生的結果,血栓症(thrombosis)則肇因於內皮細胞(endothelial cell)本身的增生。

解 決方法之一是使用塗藥支架(drug-eluting stent),此法雖能抑制血管平滑肌細胞的生長,卻會引發的血栓症。理想的支架不會妨礙內皮細胞的移動,卻能制止血管平滑肌細胞的生長。由UCSF的 Tejal Desai領軍的研究小組發現,以二氧化鈦奈米管製成的支架也許是解決之鑰。
先前的研究發現二氧化鈦奈米管陣列是理想的血管植體包 材,由於鈦金屬表面在人體中會自然形成氧化保護層,具生物相容性,因此早已廣泛使用在髖骨和牙齒植體中。此外,簡單的電化學反應就能生成高度規則排列的鉛 直二氧化鈦奈米管,而且管徑可以精確控制在22-300 nm之間,以配合細胞受體及蛋白質的特徵尺寸。

Desai等人利用微陣列分析 原始血管細胞如何在奈米管的表面生長。研究人員表示,全基因體微陣列讓他們得以檢視人類所有基因的訊息核糖核酸(mRNA)轉錄層級,從而找出可能影響血 管細胞行為的成因。結果顯示二氧化鈦奈米管會增加內皮細胞的移動性,同時抑制血管平滑肌細胞的生長,而這正是理想的血管細胞與植體的反應。

此外,研究人員找到上述反應的脈絡關係,這將有助於瞭解人體細胞對不同奈米結構是如何去感知與反應,進而利用此互動關係改良醫療裝製的設計。該團隊目前計畫找出細胞是透過何種機制感知不同的奈米材料,並用動物實驗研究奈米級表面結構對血管裝置的影響。

三、微機械元件製造技術
可應用在於微機械支管狀零件製造。

四、奈米超導
在未來,我們可以利用奈米本身的超導現象來研發更高的技術及內容。目前這是值得我們努力研發的地方。

報告人:林晧旭、蔡庭亞、汪敬軒、游博超、黃唯寧

引用出處:

 http://blog.udn.com/ncumaterials/4148286

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCDCVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drillTapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillmeXXXXXtal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolmeXXXXXtal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer.

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。   

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

beeway 發表在 痞客邦 留言(0) 人氣()

Tantalum ( /ˈtæntələm/ TAN-təl-əm; previously known as tantalium) is a chemical element with the symbol Ta and atomic number 73. A rare, hard, blue-gray, lustrous transition metal, tantalum is highly corrosion resistant and occurs naturally in the mineral tantalite, always together with the chemically similar niobium. It is part of the refractory metals group, which are widely used as minor component in alloys. The chemical inertness of tantalum makes it a valuable substance for laboratory equipment and a substitute for platinum, but its main use today is in tantalum capacitors in electronic equipment.

 

 

Contents

[hide]

  • 1 History
  • 2 Characteristics
    • 2.1 Physical properties
    • 2.2 Chemical properties
    • 2.3 Isotopes
    • 2.4 Occurrence
  • 3 Production
  • 4 Applications
    • 4.1 Electronics
    • 4.2 Alloys
    • 4.3 Other uses
  • 5 Precautions
  • 6 References
  • 7 External links

[edit] History

Tantalum was discovered in Sweden in 1802 by Anders Ekeberg. One year earlier, Charles Hatchett had discovered the element columbium.[3] In 1809, the English chemist William Hyde Wollaston compared the oxides derived from both columbium—columbite, with a density 5.918 g/cm3, and tantalum—tantalite, with a density 7.935 g/cm3, and concluded that the two oxides, despite their difference in measured density, were identical. He decided to keep the name tantalum.[4] After Friedrich Wöhler confirmed these results, it was thought that columbium and tantalum were the same element. This conclusion was disputed in 1846 by the German chemist Heinrich Rose, who argued that there were two additional elements in the tantalite sample, and he named them after the children of Tantalus: niobium (from Niobe, the goddess of tears), and pelopium (from Pelops).[5][6] The supposed element "pelopium" was later identified as a mixture of tantalum and niobium, and it was found that the niobium was identical to the columbium already discovered in 1801 by Hattchet.

The differences between tantalum and niobium were demonstrated unequivocally in 1864 by Christian Wilhelm Blomstrand,[7] and Henri Etienne Sainte-Claire Deville, as well as by Louis J. Troost, who determined the empirical formulas of some of their compounds in 1865.[7][8] Further confirmation came from the Swiss chemist Jean Charles Galissard de Marignac,[9] in 1866, who proved that there were only two elements. These discoveries did not stop scientists from publishing articles about the so-called ilmenium until 1871.[10] De Marignac was the first to produce the metallic form of tantalum in 1864, when he reduced tantalum chloride by heating it in an atmosphere of hydrogen.[11] Early investigators had been only able to produce impure tantalum, and the first relatively pure ductile metal was produced by Werner von Bolton in 1903. Wires made with metallic tantalum were used for light bulb filaments until tungsten replaced it in widespread use.[12]

The name tantalum was derived from the name of the mythological Tantalus, the father of Niobe in Greek mythology. In the story, he had been punished after death by being condemned to stand knee-deep in water with perfect fruit growing above his head, both of which eternally tantalized him. (If he bent to drink the water, it drained below the level he could reach, and if he reached for the fruit, the branches moved out of his grasp.)[13] Ekeberg wrote "This metal I call tantalum … partly in allusion to its incapacity, when immersed in acid, to absorb any and be saturated."[14]

For decades, the commercial technology for separating tantalum from niobium involved the fractional crystallization of potassium heptafluorotantalate away from potassium oxypentafluoroniobate monohydrate, a process that was discovered by Jean Charles Galissard de Marignac in 1866. This method has been supplanted by solvent extraction from fluoride-containing solutions of tantalum.[8]

[edit] Characteristics

[edit] Physical properties

Tantalum is dark (blue-gray),[15] dense, ductile, very hard, easily fabricated, and highly conductive of heat and electricity. The metal is renowned for its resistance to corrosion by acids; in fact, at temperatures below 150 °C tantalum is almost completely immune to attack by the normally aggressive aqua regia. It can be dissolved with hydrofluoric acid or acidic solutions containing the fluoride ion and sulfur trioxide, as well as with a solution of potassium hydroxide. Tantalum's high melting point of 3017 °C (boiling point 5458 °C) is exceeded only by tungsten , rhenium and osmium for metals, and carbon.

Tantalum exists in two crystalline phases, alpha and beta. The alpha phase is relatively ductile and soft; it has body-centered cubic structure (space group Im3m, lattice constant a = 0.33058 nm), Knoop hardness 200–400 HN and electrical resistivity 15–60 µΩּcm. The beta phase is hard and brittle; its crystal symmetry is tetragonal (space group P42/mnm, a = 1.0194 nm, c = 0.5313 nm), Knoop hardness is 1000–1300 HN and electrical resistivity is relatively high at 170–210 µΩּcm. The beta phase is metastable and converts to the alpha phase upon heating to 750–775 °C. Bulk tantalum is almost entirely alpha phase, and the beta phase usually exists as thin films obtained by magnetron sputtering, chemical vapor deposition or electrochemical deposition from an eutectic molten salt solution.[16]

[edit] Chemical properties

 

Tantalum forms oxides with the oxidation states +5 (Ta2O5) and +4 (TaO2).[17] The most stable oxidation state is +5, tantalum pentoxide.[17] Tantalum pentoxide is the starting material for several tantalum compounds. The compounds are created by dissolving the pentoxide in basic hydroxide solutions or by melting it in another metal oxide. Such examples are lithium tantalate (LiTaO3) and lanthanum tantalate (LaTaO4). In the lithium tantalate, the tantalate ion TaO−

3 does not occur; instead, this part of the formula represents linkage of TaO7−

6 octahedra to form a three-dimensional perovskite framework; while the lanthanum tantalate contains lone TaO3−

4 tetrahedral groups.[17]

The fluorides of tantalum can be used for its separation from niobium.[18] Tantalum forms halogen compounds in the oxidation states of +5, +4, and +3 of the type TaX5, TaX4, and TaX3, although multi core complexes and substoichiometric compounds are also known.[17][19] Tantalum pentafluoride (TaF5) is a white solid with a melting point of 97.0 °C and tantalum pentachloride (TaCl5) is a white solid with a melting point of 247.4 °C. Tantalum pentachloride is hydrolyzed by water and reacts with additional tantalum at elevated temperatures by forming the black and highly hygroscopic tantalum tetrachloride (TaCl4). While the trihalogen compounds can be obtained by reduction of the pentahalogenes with hydrogen, the dihalogen compounds do not exist.[17] A tantalum-tellurium alloy forms quasicrystals.[17] Tantalum compounds with oxidation states as low as −1 have been reported in 2008.[20]

Like most of the other refractory metals, the hardest known compounds are the stable nitrides and carbides. Tantalum carbide, TaC, like the more commonly used tungsten carbide, is a very hard ceramic that is used in cutting tools. Tantalum(III) nitride is used as a thin film insulator in some microelectronic fabrication processes.[21] Chemists at the Los Alamos National Laboratory in the United States have developed a tantalum carbide-graphite composite material that is one of the hardest materials ever synthesized. Korean researchers have developed an amorphous tantalum-tungsten-copper alloy that is more flexible and two to three times stronger than commonly used steel alloys.[22] There are two tantalum aluminides, TaAl3 and Ta3Al. These are stable, refractory, and reflective, and they have been proposed[23] as coatings for use in infrared wave mirrors.

[edit] Isotopes

Main article: Isotopes of tantalum

Natural tantalum consists of two isotopes: 180mTa (0.012%) and 181Ta (99.988%). 181Ta is a stable isotope. 180mTa (m denotes a metastable state) is predicted to decay in three ways: isomeric transition to the ground state of 180Ta, beta decay to 180W, or electron capture to 180Hf. However, radioactivity of this nuclear isomer has never been observed. Only a lower limit on its half life of over 1015 years has been set. The ground state of 180Ta has a half life of only 8 hours. 180mTa is the only naturally occurring nuclear isomer (excluding radiogenic and cosmogenic short-living nuclides). It is also the rarest isotope in the Universe, taking into account the elemental abundance of tantalum and isotopic abundance of 180mTa in the natural mixture of isotopes (and again excluding radiogenic and cosmogenic short-living nuclides).[24]

Tantalum has been examined theoretically as a "salting" material for nuclear weapons (cobalt is the better-known hypothetical salting material). An external shell of 181Ta would be irradiated by the intensive high-energy neutron flux from a hypothetical exploding nuclear weapon. This would transmute the tantalum into the radioactive isotope 182Ta, which has a half-life of 114.4 days and produces gamma rays with approximately 1.12 million electron-volts (MeV) of energy apiece, which would significantly increase the radioactivity of the nuclear fallout from the explosion for several months. Such "salted" weapons have never been built or tested, as far as is publicly known, and certainly never used as weapons.[25]

[edit] Occurrence

 

 

 

 

Tantalite, Pilbara district, Australia

Tantalum is estimated to make up about 1 ppm[26] or 2 ppm[19] of the Earth's crust by weight. There are many species of tantalum minerals, only some of which are so far being used by industry as raw materials: tantalite, microlite, wodginite, euxenite, polycrase. Tantalite (Fe,Mn) Ta2O6 is the most important mineral for tantalum extraction. Tantalite has the same mineral structure as columbite (Fe,Mn) (Ta,Nb)2O6; when there is more Ta than Nb it is called tantalite and when there is more Nb than Ta is it called columbite (or niobite). The high density of tantalite and other tantalum containing minerals makes the use of gravitational separation the best method. Other minerals include samarskite and fergusonite.

The primary mining of tantalum is in Australia, where the largest producer, Talison Minerals, now known as Global Advanced Metals, operates the Wodgina mine. Mining at Wodgina was suspended in late-2008 due to the Global Financial Crisis and is scheduled to reopen in mid 2011.[27] This mine produced tantalite, from which tantalum oxide is separated.[28] Whereas the large-scale producers of niobium are in Brazil and Canada, the ore there also yields a small percentage of tantalum. Some other countries such as China, Ethiopia, and Mozambique mine ores with a higher percentage of tantalum, and they produce a significant percentage of the world's output of it. Tantalum is also produced in Thailand and Malaysia as a by-product of the tin mining there. During gravitational separation of the ores from placer deposits, not only is Cassiterite (SnO2) found, but a small percentage of tantalite also included. The slag from the tin smelters then contains economically useful amounts of tantalum, which is leached from the slag.[8][29] Future sources of supply of tantalum, in order of estimated size, are being explored in Saudi Arabia, Egypt, Greenland, China, Mozambique, Canada, Australia, the United States, Finland, and Brazil.[30][31]

In central Africa the colloquial term coltan is used to refer to niobium (COLumbium)-containing and TANtalum-containing minerals. The United States Geological Survey reports in its 2006 yearbook that this region produced a little less than 1% of the world's tantalum output for the past four years, peaking at 10% in 2000 and 2008.[29] Ethical questions have been raised about responsible corporate behavior, human rights, and endangering wildlife, due to the exploitation of resources such as coltan in the armed conflict regions of the Congo Basin.[32][33][34][35]

According to an October 23, 2003 United Nations report,[36] the smuggling and exportation of coltan has helped fuel the war in the Congo, a crisis that has resulted in approximately 5.4 million deaths since 1998[37] – making it the world’s deadliest documented conflict since World War II.

[edit] Production

Several steps are involved in the extraction of tantalum from tantalite: First the mineral is crushed and concentrated by gravity separation. This is generally carried out near the mine site. Further processing by chemical separation is usually done by treating the ores with a mixture of hydrofluoric acid and sulfuric acid at over 90°C. This causes the tantalum and niobium to dissolve as complex fluorides, which can be separated from the impurities.

 

Ta2O5 + 14 HF → 2 H2[TaF7] + 5 H2O

 

Nb2O5 + 10 HF → 2 H2[NbOF5] + 3 H2O

The first industrial-scale separation, developed by de Marignac, used the difference in solubility between the complex niobium and tantalum fluorides K2[NbOF5]•H2O (dipotassium oxypentafluoroniobate monohydrate) and K2[TaF7] (dipotassium heptafluorotantalate) in water. Newer processes use the liquid extraction of the fluorides from aqueous solution by organic solvents such as cyclohexanone.[18] The complex niobium and tantalum fluorides are extracted separately from the organic solvent with water, and either precipitated by the addition of potassium fluoride to produce a potassium fluoride complex, or precipitated with ammonia as the pentoxide:[17]

 

H2[TaF7] + KF → K2[TaF7]↓ + HF

 

2 H2[TaF7] + 14 NH4OH → Ta2O5↓ + 14 NH4F + 9 H2O

The resulting potassium fluorotantalate salt is generally treated by reduction with molten sodium to produce a coarse tantalum powder.[38]

[edit] Applications

[edit] Electronics

 

 

 

 

Tantalum electrolytic capacitor

The major use for tantalum, as the metal powder, is in the production of electronic components, mainly capacitors and some high-power resistors.[39] Tantalum electrolytic capacitors exploit the tendency of tantalum to form a protective oxide surface layer, using tantalum powder, pressed into a pellet shape, as one "plate" of the capacitor, the oxide as the dielectric, and an electrolytic solution or conductive solid as the other "plate". Because the dielectric layer can be very thin (thinner than the similar layer in, for instance, an aluminium electrolytic capacitor), a high capacitance can be achieved in a small volume. Because of the size and weight advantages, tantalum capacitors are attractive for portable telephones, personal computers, and automotive electronics.[40]

[edit] Alloys

Tantalum is also used to produce a variety of alloys that have high melting points, are strong and have good ductility. Alloyed with other metals, it is also used in making carbide tools for metalworking equipment and in the production of superalloys for jet engine components, chemical process equipment, nuclear reactors, and missile parts.[40][41] Because of its ductility, tantalum can be drawn into fine wires or filaments, which are used for evaporating metals such as aluminium. Since it resists attack by body fluids and is nonirritating, tantalum is widely used in making surgical instruments and implants. For example, porous tantalum coatings are used in the construction of orthopedic implants due to tantalum's ability to form a direct bond to hard tissue.[42]

Tantalum is inert against most acids except hydrofluoric acid and hot sulfuric acid, also hot alkaline solutions cause tantalum to corrode. This property makes it an ideal metal for chemical reaction vessels and pipes for corrosive liquids. Heat exchanging coils for the steam heating of hydrochloric acid are made from tantalum.[43] Tantalum was extensively used in the production of ultra high frequency electron tubes for radio transmitters. The tantalum is capable of capturing oxygen and nitrogen by forming nitrides and oxides and therefore helps to sustain the high vacuum needed for the tubes.[18][43]

[edit] Other uses

The oxide is used to make special high refractive index glass for camera lenses.[44] The high melting point and oxidation resistance lead to the use of the metal in the production of vacuum furnace parts. Due to its high density, shaped charge and explosively formed penetrator liners have been constructed from tantalum.[45] Tantalum greatly increases the armor penetration capabilities of a shaped charge due to its high density and high melting point.[46][47] It is also occasionally used in precious watches e.g. from Hublot, Montblanc and Panerai. Tantalum is also highly bioinert and is used as an orthopedic implant material.[48]

[edit] Precautions

Compounds containing tantalum are rarely encountered in the laboratory. The metal is highly biocompatible and is used for body implants and coatings, therefore attention may be focused on other elements or the physical nature of the chemical compound.[49] A single study[50] is the only reference in literature linking tantalum to local sarcomas. It is possible the result was due to other factors not considered in the study. The study was quoted in IARC Monograph vol. 74 which includes the following "Note to the reader": "Inclusion of an agent in the Monographs does not imply that it is a carcinogen, only that the published data have been examined."[51]

[edit] References

  1. ^ Moseley, P. T.; Seabrook, C. J. (1973). "The crystal structure of β-tantalum". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry 29: 1170–1171. doi:10.1107/S0567740873004140.  edit
  2. ^ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
  3. ^ Griffith, William P.; Morris, Peter J. T. (2003). "Charles Hatchett FRS (1765-1847), Chemist and Discoverer of Niobium". Notes and Records of the Royal Society of London 57 (3): 299. doi:10.1098/rsnr.2003.0216. http://www.jstor.org/stable/3557720
  4. ^ Wollaston, William Hyde (1809). "On the Identity of Columbium and Tantalum". Philosophical Transactions of the Royal Society of London 99: 246–252. doi:10.1098/rstl.1809.0017. http://www.jstor.org/stable/107264
  5. ^ Rose, Heinrich (1844). "Ueber die Zusammensetzung der Tantalite und ein im Tantalite von Baiern enthaltenes neues Metall" (in German). Annalen der Physik 139 (10): 317–341. doi:10.1002/andp.18441391006. http://gallica.bnf.fr/ark:/12148/bpt6k15148n/f327.table
  6. ^ Rose, Heinrich (1847). "Ueber die Säure im Columbit von Nordamérika" (in German). Annalen der Physik 146 (4): 572–577. doi:10.1002/andp.18471460410. http://gallica.bnf.fr/ark:/12148/bpt6k15155x/f586.table
  7. ^ a b Marignac, Blomstrand, H. Deville, L. Troost und R. Hermann (1866). "Tantalsäure, Niobsäure, (Ilmensäure) und Titansäure". Fresenius' Journal of Analytical Chemistry 5 (1): 384–389. doi:10.1007/BF01302537. 
  8. ^ a b c Gupta, C. K.; Suri, A. K. (1994). Extractive Metallurgy of Niobium. CRC Press. ISBN 0849360714. 
  9. ^ Marignac, M. C. (1866). "Recherches sur les combinaisons du niobium" (in French). Annales de chimie et de physique 4 (8): 7–75. http://gallica.bnf.fr/ark:/12148/bpt6k34818t/f4.table
  10. ^ Hermann, R. (1871). "Fortgesetzte Untersuchungen über die Verbindungen von Ilmenium und Niobium, sowie über die Zusammensetzung der Niobmineralien (Further research about the compounds of ilmenium and niobium, as well as the composition of niobium minerals)" (in German). Journal für Praktische Chemie 3 (1): 373–427. doi:10.1002/prac.18710030137. 
  11. ^ "Niobium". Universidade de Coimbra. http://nautilus.fis.uc.pt/st2.5/scenes-e/elem/e04100.html. Retrieved 2008-09-05. 
  12. ^ Bowers, B. (2001). "Scanning Our Past from London The Filament Lamp and New Materials". Proceedings of the IEEE 89 (3): 413. doi:10.1109/5.915382. 
  13. ^ Aycan, Mugla, Sule (2005). "Chemistry Education and Mythology". Journal of Social Sciences 1 (4): 238– 239. doi:10.3844/jssp.2005.238.239. 
  14. ^ Greenwood, Norman N.; Earnshaw, Alan. (1997), Chemistry of the Elements (2nd ed.), Oxford: Butterworth-Heinemann, p. 1138, ISBN 0080379419 
  15. ^ Colakis, Marianthe; Masello, Mary Joan (2007-06-30). "Tantalum". Classical Mythology & More: A Reader Workbook. ISBN 9780865165731. http://books.google.com/?id=5o3Lr2Swz8sC&pg=PA204
  16. ^ Lee, S (2004). "Texture, structure and phase transformation in sputter beta tantalum coating". Surface and Coatings Technology 177-178: 44. doi:10.1016/j.surfcoat.2003.06.008. 
  17. ^ a b c d e f g Holleman, A. F., Wiberg, E., Wiberg, N. (2007). Lehrbuch der Anorganischen Chemie, 102nd ed.. de Gruyter. ISBN 978-3-11-017770-1. 
  18. ^ a b c Soisson, Donald J.; McLafferty, J. J.; Pierret, James A. (1961). "Staff-Industry Collaborative Report: Tantalum and Niobium". Ind. Eng. Chem. 53 (11): 861–868. doi:10.1021/ie50623a016. 
  19. ^ a b Agulyansky, Anatoly (2004). The Chemistry of Tantalum and Niobium Fluoride Compounds. Elsevier. ISBN 9780444516046. http://books.google.com/?id=Z-4QXNB5Hp8C. Retrieved 2008-09-02. 
  20. ^ Morse, P. M. et al. (2008). "Ethylene Complexes of the Early Transition Metals: Crystal Structures of [HfEt4(C2H4)2− ] and the Negative-Oxidation-State Species [TaHEt(C2H4)3−

    3] and [WH(C2H4)3−

    4]". Organometallics 27 (5): 984. doi:10.1021/om701189e. 
  21. ^ Tsukimoto, S.; Moriyama, M.; Murakami, Masanori (1961). "Microstructure of amorphous tantalum nitride thin films". Thin Solid Films 460 (1-2): 222–226. doi:10.1016/j.tsf.2004.01.073. 
  22. ^ Arirang, TV (2005-05-06). "Researchers Develop New Alloy". Digital Chosunilbo (English Edition) : Daily News in English About Korea. Archived from the original on March 28, 2008. http://web.archive.org/web/20080328220843/http://english.chosun.com/w21data/html/news/200505/200505060005.html. Retrieved 2008-12-22. 
  23. ^ Braun, Hilarion "Substance for front surface mirror" U.S. Patent 5,923,464, Issued on July 13, 1999
  24. ^ Georges, Audi (2003). "The NUBASE Evaluation of Nuclear and Decay Properties". Nuclear Physics A (Atomic Mass Data Center) 729: 3–128. doi:10.1016/j.nuclphysa.2003.11.001. 
  25. ^ Win, David Tin; Masum, Al (2003) (PDF). Weapons of Mass Destruction. 6. pp. 199– 219. http://www.journal.au.edu/au_techno/2003/apr2003/aujt6-4_article07.pdf
  26. ^ Emsley, John (2001). "Tantalum". Nature's Building Blocks: An A-Z Guide to the Elements. Oxford, England, UK: Oxford University Press. p. 420. ISBN 0198503407. 
  27. ^ "Talison Tantalum eyes mid-2011 Wodgina restart 2010-06-09". Reuters. 2010-06-09. http://af.reuters.com/article/drcNews/idAFLDE6530TW20100609. Retrieved 2010-08-27. 
  28. ^ "Wodgina Operations". Talison Minerals. 2008. http://www.talison.com.au/operations.html. Retrieved 2009-07-31. [dead link]
  29. ^ a b Papp, John F. (2006). "2006 Minerals Yearbook Nb & Ta". US Geological Survey. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/#pubs. Retrieved 2008-06-03. 
  30. ^ "Tantalum supplement" (PDF). Mining Journal. 2007-November. http://www.noventa.net/pdf/presentations/tanatalumSCR_presentation.pdf. Retrieved 2008-06-03. 
  31. ^ "International tantalum resources — exploration and mining" (pdf). GSWA Mineral Resources Bulletin 22 (10). http://www.doir.wa.gov.au/documents/gswa/gsdMRB_22_chap10.pdf
  32. ^ Hayes, Karen; Burge, Richard. Coltan Mining in the Democratic Republic of Congo: How tantalum-using industries can commit to the reconstruction of the DRC. 1–64. ISBN 1903703107. 
  33. ^ "Congo's Bloody Coltan". http://www.pulitzercenter.org/openitem.cfm?id=177. Retrieved 2009-08-08. 
  34. ^ "Congo War and the Role of Coltan". http://www1.american.edu/ted/ice/congo-coltan.htm. Retrieved 2009-08-08. 
  35. ^ "Coltan mining in the Congo River Basin". http://www.panda.org/what_we_do/where_we_work/congo_basin_forests/problems/mining/coltan_mining/. Retrieved 2009-08-08. 
  36. ^ "S/2003/1027". 2003-10-26. http://www.un.org/Docs/journal/asp/ws.asp?m=S%2F2003%2F1027. Retrieved 2008-04-19. 
  37. ^ "Special Report: Congo". International Rescue Committee. http://www.theirc.org/special-report/congo-forgotten-crisis.html. Retrieved 2008-04-19. 
  38. ^ "Extraction/refining". T.I.C.. http://tanb.org/tantalum. Retrieved 2009-07-07. 
  39. ^ "What is a resistor?". http://www.wisegeek.com/what-is-a-resistor.htm. Retrieved 2009-08-08. 
  40. ^ a b "Commodity Report 2008: Tantalum" (PDF). United States Geological Survey. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/mcs-2008-tanta.pdf. Retrieved 2008-10-24. 
  41. ^ Buckman Jr., R. W. (2000). "New applications for tantalum and tantalum alloys". JOM Journal of the Minerals, Metals and Materials Society 52 (3): 40. doi:10.1007/s11837-000-0100-6. 
  42. ^ Cohen, R. (2006). "Applications of porous tantalum in total hip arthroplasty". Journal of the American Academy of Orthopaedic Surgeons 14: 646. 
  43. ^ a b Balke, Clarence W.. "Columbium and Tantalum". Industrial and Engineering Chemistry 20 (10): 1166. 
  44. ^ Musikant, Solomon (1985). "Optical Glas Composition". Optical Materials: An Introduction to Selection and Application. CRC Press. p. 28. ISBN 9780824773090. http://books.google.com/?id=iJEXMF3JBtQC&pg=PA28
  45. ^ Nemat-Nasser, Sia; Isaacs, Jon B.; Liu, Mingqi (1998). "Microstructure of high-strain, high-strain-rate deformed tantalum". Acta Materialia 46: 1307. doi:10.1016/S1359-6454(97)00746-5. 
  46. ^ Walters, William; Cooch, William; Burkins, Matthew (2001). "The penetration resistance of a titanium alloy against jets from tantalum shaped charge liners". International Journal of Impact Engineering 26: 823. doi:10.1016/S0734-743X(01)00135-X. 
  47. ^ Russell, Alan M.; Lee, Kok Loong (2005). Structure-property relations in nonferrous metals. Hoboken, NJ: Wiley-Interscience. p. 218. ISBN 9780471649526. http://books.google.com/?id=fIu58uZTE-gC&pg=PA129&lpg=PP128#PPA218
  48. ^ Black, J. (1994). "Biological performance of tantalum". Clin Mater. 16 (3): 167–173. doi:10.1016/0267-6605(94)90113-9. PMID /10172264. 
  49. ^ Matsuno H, Yokoyama A, Watari F, Uo M, Kawasaki T. (2001). "Biocompatibility and osteogenesis of refractory metal implants, titanium, hafnium, niobium, tantalum and rhenium. Biocompatibility of tantalum". Biomaterials 22: 1253. doi:10.1016/S0142-9612(00)00275-1. http://www.ncbi.nlm.nih.gov/pubmed/11336297
  50. ^ Oppenheimer, B.S.; Oppenheimer, E.T.; Danishefsky, I.; Stout, A.P. (1956). "Carcinogenic effects of metals in rodent". Cancer Research 16: 439. http://cancerres.aacrjournals.org/cgi/reprint/16/5/439.pdf
  51. ^ "Surgical implants and other foreign bodies". IARC. 1999. http://www.inchem.org/documents/iarc/vol74/implants.html. Retrieved 2009-06-03.



 

引用出處: 

 http://en.wikipedia.org/wiki/Tantalum

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!  

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com/ / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drillTapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer. 

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。   

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

 

beeway 發表在 痞客邦 留言(0) 人氣()

Niobium ( /naɪˈoʊbiəm/ nye-OH-bee-əm; from Greek mythology: Niobe, daughter of Tantalus), or columbium ( /kəˈlʌmbiəm/ kə-LUM-bee-əm), is the chemical element with the symbol Nb and the atomic number 41. A rare, soft, grey, ductile transition metal, niobium is found in the minerals pyrochlore, the main commercial source for niobium, and columbite.

Niobium has physical and chemical properties similar to those of the element tantalum, and the two are therefore difficult to distinguish. The English chemist Charles Hatchett reported a new element similar to tantalum in 1801, and named it columbium. In 1809, the English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. The German chemist Heinrich Rose determined in 1846 that tantalum ores contain a second element, which he named niobium. In 1864 and 1865, a series of scientific findings clarified that niobium and columbium were the same element (as distinguished from tantalum), and for a century both names were used interchangeably. The name of the element was officially adopted as niobium in 1949.

It was not until the early 20th century that niobium was first used commercially. Brazil is the leading producer of niobium and ferroniobium, an alloy of niobium and iron. Niobium is used mostly in alloys, the largest part in special steel such as that used in gas pipelines. Although alloys contain only a maximum of 0.1%, that small percentage of niobium improves the strength of the steel. The temperature stability of niobium-containing superalloys is important for its use in jet and rocket engines. Niobium is used in various superconducting materials. These superconducting alloys, also containing titanium and tin, are widely used in the superconducting magnets of MRI scanners. Other applications of niobium include its use in welding, nuclear industries, electronics, optics, numismatics and jewelry. In the last two applications, niobium's low toxicity and ability to be coloured by anodisation are particular advantages.

 

 

Contents

[hide]

  • 1 History
    • 1.1 Naming of the element
  • 2 Characteristics
    • 2.1 Physical
    • 2.2 Chemical
    • 2.3 Isotopes
    • 2.4 Occurrence
  • 3 Production
  • 4 Compounds
    • 4.1 Oxides and sulfides
    • 4.2 Halides
    • 4.3 Nitrides and carbides
  • 5 Applications
    • 5.1 Steel production
    • 5.2 Superalloys
    • 5.3 Superconducting magnets
      • 5.3.1 Superconducting, other
    • 5.4 Other uses
      • 5.4.1 Electroceramics
      • 5.4.2 Hypoallergenic applications: medicine and jewelry
      • 5.4.3 Numismatics
      • 5.4.4 Other
  • 6 Precautions
  • 7 References
  • 8 External links

[edit] History

 

 

 

 

Charles Hatchett discoverer of columbium.

 

 

 

 

Picture of a Hellenistic sculpture representing Niobe by Giorgio Sommer

Niobium was discovered by the English chemist Charles Hatchett in 1801.[1] He found a new element in a mineral sample that had been sent to England from Massachusetts, United States in 1734 by a John Winthrop,[2] and named the mineral columbite and the new element columbium after Columbia, the poetical name for America.[3] The columbium discovered by Hatchett was probably a mixture of the new element with tantalum.[3]

Subsequently, there was considerable confusion[4] over the difference between columbium (niobium) and the closely related tantalum. In 1809, the English chemist William Hyde Wollaston compared the oxides derived from both columbium—columbite, with a density 5.918 g/cm3, and tantalum—tantalite, with a density 7.935 g/cm3, and concluded that the two oxides, despite the significant difference in density, were identical; thus he kept the name tantalum.[4] This conclusion was disputed in 1846 by the German chemist Heinrich Rose, who argued that there were two different elements in the tantalite sample, and named them after children of Tantalus: niobium (from Niobe), and pelopium (from Pelops).[5][6] This confusion arose from the minimal observed differences between tantalum and niobium. The claimed new elements pelopium, ilmenium and dianium[7] were in fact identical to niobium or mixtures of niobium and tantalum.[8]

The differences between tantalum and niobium were unequivocally demonstrated in 1864 by Christian Wilhelm Blomstrand,[8] and Henri Etienne Sainte-Claire Deville, as well as Louis J. Troost, who determined the formulas of some of the compounds in 1865[8][9] and finally by the Swiss chemist Jean Charles Galissard de Marignac[10] in 1866, who all proved that there were only two elements. Articles on ilmenium continued to appear until 1871.[11]

De Marignac was the first to prepare the metal in 1864, when he reduced niobium chloride by heating it in an atmosphere of hydrogen.[12] Although de Marignac was able to produce tantalum-free niobium on a larger scale by 1866, it was not until the early 20th century that niobium was first used commercially, in incandescent lamp filaments.[9] This use quickly became obsolete through the replacement of niobium with tungsten, which has a higher melting point and thus is preferable for use in incandescent lamps. The discovery that niobium improves the strength of steel was made in the 1920s, and this application remains its predominant use.[9] In 1961 the American physicist Eugene Kunzler and coworkers at Bell Labs discovered that niobium-tin continues to exhibit superconductivity in the presence of strong electric currents and magnetic fields,[13] making it the first material to support the high currents and fields necessary for useful high-power magnets and electrically powered machinery. This discovery would allow — two decades later — the production of long multi-strand cables that could be wound into coils to create large, powerful electromagnets for rotating machinery, particle accelerators, or particle detectors.[14][15]

[edit] Naming of the element

Columbium (symbol Cb[16]) was the name originally given to this element by Hatchett, and this name remained in use in American journals—the last paper published by American Chemical Society with columbium in its title dates from 1953[17]—while niobium was used in Europe. To end this confusion, the name niobium was chosen for element 41 at the 15th Conference of the Union of Chemistry in Amsterdam in 1949.[18] A year later this name was officially adopted by the International Union of Pure and Applied Chemistry (IUPAC) after 100 years of controversy, despite the chronological precedence of the name Columbium.[18] The latter name is still sometimes used in US industry.[19] This was a compromise of sorts;[18] the IUPAC accepted tungsten instead of wolfram, in deference to North American usage; and niobium instead of columbium, in deference to European usage. Not everyone agreed, and while many leading chemical societies and government organizations refer to it by the official IUPAC name, many leading metallurgists, metal societies, and the United States Geological Survey still refer to the metal by the original "columbium".[20][21]

[edit] Characteristics

[edit] Physical

Niobium is a lustrous, grey, ductile, paramagnetic metal in group 5 of the periodic table (see table), although it has an atypical configuration in its outermost electron shells compared to the rest of the members. (This can be observed in the neighborhood of niobium (41), ruthenium (44), rhodium (45), and palladium (46).)

Z Element No. of electrons/shell

23 vanadium 2, 8, 11, 2

41 niobium 2, 8, 18, 12, 1

73 tantalum 2, 8, 18, 32, 11, 2

105 dubnium 2, 8, 18, 32, 32, 11, 2

Niobium becomes a superconductor at cryogenic temperatures. At atmospheric pressure, it has the highest critical temperature of the elemental superconductors: 9.2 K.[22] Niobium has the largest magnetic penetration depth of any element.[22] In addition, it is one of the three elemental Type II superconductors, along with vanadium and technetium. The superconductive properties are strongly dependent on the purity of the niobium metal.[23] When very pure, it is comparatively soft and ductile, but impurities make it harder.[24]

The metal has a low capture cross-section for thermal neutrons;[25] thus it is used in the nuclear industries.[26]

[edit] Chemical

The metal takes on a bluish tinge when exposed to air at room temperature for extended periods.[27] Despite presenting a high melting point in elemental form (2,468 °C), it has a low density in comparison to other refractory metals. Furthermore, it is corrosion resistant, exhibits superconductivity properties, and forms dielectric oxide layers.

Niobium is slightly less electropositive and more compact than its predecessor in the periodic table, zirconium, whereas it is virtually identical in size to the heavier tantalum atoms, owing to the lanthanide contraction.[24] As a result, niobium's chemical properties are very similar to those for tantalum, which appears directly below niobium in the periodic table.[9] Although its corrosion resistance is not as outstanding as that of tantalum, its lower price and greater availability make niobium attractive for less demanding uses such as linings in chemical plants.[24]

[edit] Isotopes

Main article: Isotopes of niobium

Naturally occurring niobium is composed of one stable isotope, 93Nb.[28] As of 2003, at least 32 radioisotopes have also been synthesized, ranging in atomic mass from 81 to 113. The most stable of these is 92Nb with a half-life of 34.7 million years. One of the least stable is 113Nb, with an estimated half-life of 30 milliseconds. Isotopes that are lighter than the stable 93Nb tend to decay by β+ decay, and those that are heavier tend to decay by β- decay, with some exceptions. 81Nb, 82Nb, and 84Nb have minor β+ delayed proton emission decay paths, 91Nb decays by electron capture and positron emission, and 92Nb decays by both β+ and β- decay.[28]

At least 25 nuclear isomers have been described, ranging in atomic mass from 84 to 104. Within this range, only 96Nb, 101Nb, and 103Nb do not have isomers. The most stable of niobium's isomers is 93mNb with a half-life of 16.13 years. The least stable isomer is 84mNb with a half-life of 103 ns. All of niobium's isomers decay by isomeric transition or beta decay except 92m1Nb, which has a minor electron capture decay chain.[28]

[edit] Occurrence

See also: Category:Niobium minerals

Niobium is estimated to be 33rd on the list of the most common elements in the Earth’s crust with 20 ppm.[29] The abundance on Earth should be much greater, but the “missing” niobium may be located in the Earth’s core due to the metal's high density.[20] The free element is not found in nature, but it does occur in minerals.[24] Minerals that contain niobium often also contain tantalum, such as columbite ((Fe,Mn)(Nb,Ta)2O6) and columbite-tantalite (or coltan, (Fe,Mn)(Ta,Nb)2O6).[30] Columbite-tantalite minerals are most usually found as accessory minerals in pegmatite intrusions, and in alkaline intrusive rocks. Less common are the niobates of calcium, uranium, thorium and the rare earth elements such as pyrochlore ((Na,Ca)2Nb2O6(OH,F)) and euxenite ((Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6). These large deposits of niobium have been found associated with carbonatites (carbonate-silicate igneous rocks) and as a constituent of pyrochlore.[31]

The two largest deposits of pyrochlore were found in the 1950s in Brazil and Canada, and both countries are still the major producers of niobium mineral concentrates.[9] The largest deposit is hosted within a carbonatite intrusion at Araxá, Minas Gerais Brazil, owned by CBMM (Companhia Brasileira de Metalurgia e Mineração); the other deposit is located at Catalão, Goiás owned by Anglo American plc (through its subsidiary Mineração Catalão), also hosted within a carbonatite intrusion.[32] Altogether these two Brazilian mines produce around 75% of world supply. The third largest producer of niobium is the carbonatite-hosted Niobec Mine, Saint-Honoré near Chicoutimi, Quebec owned by Iamgold Corporation Ltd, which produces around 7% of world supply.[32]

Extensive unexploited resources are located in Nigeria, Democratic Republic of Congo, Tanzania, Malawi, Australia, Afghanistan, Russia and Colombia.

[edit] Production

 

 

 

 

Niobium producers in 2007

After the separation from the other minerals, the mixed oxides of tantalum Ta2O5 and niobium Nb2O5 are obtained. The first step in the processing is the reaction of the oxides with hydrofluoric acid:[30]

 

Ta2O5 + 14 HF → 2 H2[TaF7] + 5 H2ONb2O5 + 10 HF → 2 H2[NbOF5] + 3 H2O

The first industrial scale separation, developed by de Marignac, exploits the differing solubilities of the complex niobium and tantalum fluorides, dipotassium oxypentafluoroniobate monohydrate (K2[NbOF5]·H2O) and dipotassium heptafluorotantalate (K2[TaF7]) in water. Newer processes use the liquid extraction of the fluorides from aqueous solution by organic solvents like cyclohexanone.[30] The complex niobium and tantalum fluorides are extracted separately from the organic solvent with water and either precipitated by the addition of potassium fluoride to produce a potassium fluoride complex, or precipitated with ammonia as the pentoxide:[33]

 

H2[NbOF5] + 2 KF → K2[NbOF5]↓ + 2 HF

Followed by:

 

2 H2[NbOF5] + 10 NH4OH → Nb2O5↓ + 10 NH4F + 7 H2O

Several methods are used for the reduction to metallic niobium. The electrolysis of a molten mixture of K2[NbOF5] and sodium chloride is one; the other is the reduction of the fluoride with sodium. With this method niobium with a relatively high purity can be obtained. In large scale production the reduction of Nb2O5 with hydrogen or carbon[33] is used. In the process involving the aluminothermic reaction a mixture of iron oxide and niobium oxide is reacted with aluminium:

 

3 Nb2O5 + Fe2O3 + 12 Al → 6 Nb + 2 Fe + 6 Al2O3

To enhance the reaction, small amounts of oxidizers like sodium nitrate are added. The result is aluminium oxide and ferroniobium, an alloy of iron and niobium used in the steel production.[34][35] The ferroniobium contains between 60 and 70% of niobium.[32] Without addition of iron oxide, aluminothermic process is used for the production of niobium. Further purification is necessary to reach the grade for superconductive alloys. Electron beam melting under vacuum is the method used by the two major distributors of niobium.[36][37]

The United States Geological Survey estimates that the production increased from 38,700 metric tonnes in 2005 to 44,500 tonnes in 2006.[38][39] The worldwide resources are estimated to be 4,400,000 tonnes.[39] During the ten-year period between 1995 and 2005, the production more than doubled, starting from 17,800 tonnes in 1995.[40]

[edit] Compounds

See also: Category:Niobium compounds

Niobium is in many ways similar to tantalum and zirconium. It reacts with most nonmetals at high temperatures: niobium reacts with fluorine at room temperature, with chlorine and hydrogen at 200 °C, and with nitrogen at 400 °C, giving products that are frequently interstitial and nonstoichiometric.[24] The metal begins to oxidize in air at 200 °C,[33] and is resistant to corrosion by fused alkalis and by acids, including aqua regia, hydrochloric, sulfuric, nitric and phosphoric acids.[24] Niobium is attacked by hydrofluoric acid and hydrofluoric/nitric acid mixtures.

Although niobium exhibits all of the formal oxidation states from +5 to -1, in most commonly encountered compounds, it is found in the +5 state.[24] Characteristically, compounds in oxidation state less than 5+ display Nb-Nb bonding.

[edit] Oxides and sulfides

Niobium forms oxides with the oxidation states +5 (Nb2O5), +4 (NbO2), and +3 (Nb2O3),[33] as well as with the rarer oxidation state +2 (NbO).[41] Most commonly encountered is the pentoxide, precursor to almost all niobium compounds and alloys.[33][42] Niobates are generated by dissolving the pentoxide in basic hydroxide solutions or by melting it in alkali metal oxides. Examples are lithium niobate (LiNbO3) and lanthanum niobate (LaNbO4). In the lithium niobate is a trigonally distorted perovskite-like structure, whereas the lanthanum niobate contains lone NbO43− ions.[33] The layered niobium sulfide (NbS2) is also known.[24]

[edit] Halides

 

 

 

 

A sample of niobium pentachloride (yellow portion) that has partially hydrolyzed (white material).

 

 

 

 

Ball-and-stick model of niobium pentachloride, which exists as a dimer.

Niobium forms halides in the oxidation states of +5 and +4 as well as diverse substoichiometric compounds.[33][36] The pentahalides (NbX5) feature octahedral Nb centres. Niobium pentafluoride (NbF5) is a white solid with a melting point of 79.0 °C and niobium pentachloride (NbCl5) is yellow (see image at left) with a melting point of 203.4 °C. Both are hydrolyzed to give oxides and oxyhalides, such as NbOCl3. The pentachloride is a versatile reagent being used to generate the organometallic compounds, such as niobocene dichloride ((C5H5)2NbCl2).[43] The tetrahalides (NbX4) are dark-coloured polymers with Nb-Nb bonds, for example the black hygroscopic niobium tetrafluoride (NbF4) and brown niobium tetrachloride (NbCl4).

Anionic halide compounds of niobium are well known, owing in part to the Lewis acidity of the pentahalides. The most important is [NbF7]2-, which is an intermediate in the separation of Nb and Ta from the ores.[30] This heptafluoride tends to form the oxopentafluoride more readily than does the tantalum compound.Other halide complexes include octahedral [NbCl6]-:

 

Nb2Cl10 + 2 Cl- → 2 [NbCl6]-

As for other early metals, a variety of reduced halide clusters are known, the premier example being [Nb6Cl18]4-.[44]

[edit] Nitrides and carbides

Other binary compounds of niobium include the niobium nitride (NbN), which becomes a superconductor at low temperatures and is used in detectors for infrared light.[45] The main niobium carbide is NbC, an extremely hard, refractory, ceramic material, commercially used in tool bits for cutting tools.

[edit] Applications

 

 

 

 

A niobium foil

It is estimated that out of 44,500 metric tons of niobium mined in 2006, 90% was used in the production of high-grade structural steel, followed by its use in superalloys.[46] The use of niobium alloys for superconductors and in electronic components account only for a small share of the production.[46]

[edit] Steel production

Niobium is an effective microalloying element for steel. Adding niobium to the steel causes the formation of niobium carbide and niobium nitride within the structure of the steel.[20] These compounds improve the grain refining, retardation of recrystallization, and precipitation hardening of the steel. These effects in turn increase the toughness, strength, formability, and weldability of the microalloyed steel.[20] Microalloyed stainless steels have a niobium content of less than 0.1%.[47] It is an important alloy addition to high strength low alloy steels which are widely used as structural components in modern automobiles.[20] These niobium containing alloys are strong and are often used in pipeline construction.[48][49]

[edit] Superalloys

 

 

 

 

Apollo 15 CSM in lunar orbit with the dark rocket nozzle made from niobium-titanium alloy

Appreciable amounts of the element, either in its pure form or in the form of high-purity ferroniobium and nickel niobium, are used in nickel-, cobalt-, and iron-based superalloys for such applications as jet engine components, gas turbines, rocket subassemblies, and heat resisting and combustion equipment. Niobium precipitates a hardening γ''-phase within the grain structure of the superalloy.[50] The alloys contain up to 6.5% niobium.[47] One example of a nickel-based niobium-containing superalloy is Inconel 718, which consists of roughly 50% nickel, 18.6% chromium, 18.5% iron, 5% niobium, 3.1% molybdenum, 0.9% titanium, and 0.4% aluminium.[51][52] These superalloys are used, for example, in advanced air frame systems such as those used in the Gemini program.

An alloy used for liquid rocket thruster nozzles, such as in the main engine of the Apollo Lunar Modules, is C103, which consists of 89% niobium, 10% hafnium and 1% titanium.[53] Another niobium alloy was used for the nozzle of the Apollo Service Module. As niobium is oxidized at temperatures above 400 °C, a protective coating is necessary for these applications to prevent the alloy from becoming brittle.[53]

[edit] Superconducting magnets

 

 

 

 

A 3 tesla clinical magnetic resonance imaging scanner using niobium-superconducting alloy

Niobium-germanium (Nb3Ge), niobium-tin (Nb3Sn), as well as the niobium-titanium alloys are used as a type II superconductor wire for superconducting magnets.[54][55] These superconducting magnets are used in magnetic resonance imaging and nuclear magnetic resonance instruments as well as in particle accelerators.[56] For example, the Large Hadron Collider uses 600 metric tons of superconducting strands, while the International Thermonuclear Experimental Reactor is estimated to use 600 metric tonnes of Nb3Sn strands and 250 metric tonnes of NbTi strands.[57] In 1992 alone, niobium-titanium wires were used to construct more than US$1 billion worth of clinical magnetic resonance imaging systems.[14]

[edit] Superconducting, other

The Superconducting Radio Frequency (RF) cavities used in the free electron lasers TESLA and XFEL are made from pure niobium.[58]

The high sensitivity of superconducting niobium nitride bolometers make them an ideal detector for electromagnetic radiation in the THz frequency band. These detectors were tested at the Heinrich Hertz Submillimeter Telescope, the South Pole Telescope, the Receiver Lab Telescope, and at APEX and are now used in the HIFI instrument on board the Herschel Space Observatory.[59]

[edit] Other uses

[edit] Electroceramics

Lithium niobate, which is a ferroelectric, is used extensively in mobile telephones and optical modulators, and for the manufacture of surface acoustic wave devices. It belongs to the ABO3 structure ferroelectrics like lithium tantalate and barium titanate.[60] Niobium was evaluated as a cheaper alternative to tantalum in capacitors,[61] but tantalum capacitors are still predominant. Niobium is added to glass in order to attain a higher refractive index, a property of use to the optical industry in making thinner corrective glasses.

[edit] Hypoallergenic applications: medicine and jewelry

Niobium and some niobium alloys are physiologically inert and thus hypoallergenic. For this reason, niobium is found in many medical devices such as pacemakers.[62] Niobium treated with sodium hydroxide forms a porous layer that aids osseointegration.[63]

Along with titanium, tantalum, and aluminium, niobium can also be electrically heated and anodized, resulting in a wide array of colours using a process known as reactive metal anodizing which is useful in making jewelry.[64][65] The fact that niobium is hypoallergenic also benefits its use in jewelry.[66]

[edit] Numismatics

 

 

 

 

A 150 Years Semmering Alpine Railway Coin made of niobium and silver

Niobium is used as a precious metal in commemorative coins, often with silver or gold. For example, Austria produced a series of silver niobium euro coins starting in 2003; the colour in these coins is created by diffraction of light by a thin oxide layer produced by anodising.[67] In 2008, six coins are available showing a broad variety of colours in the centre of the coin: blue, green, brown, purple, violet, or yellow. Two more examples are the 2004 Austrian €25 150 Years Semmering Alpine Railway commemorative coin,[68] and the 2006 Austrian €25 European Satellite Navigation commemorative coin.[69] Latvia produced a similar series of coins starting in 2004,[70] with one following in 2007.[71]

[edit] Other

The arc-tube seals of high pressure sodium vapor lamps are made from niobium, or niobium with 1% of zirconium, because niobium has a very similar coefficient of thermal expansion to the sintered alumina arc tube ceramic, a translucent material which resists chemical attack or reduction by the hot liquid sodium and sodium vapour contained inside the operating lamp.[72][73][74] The metal is also used in arc welding rods for some stabilized grades of stainless steel.[75]

[edit] Precautions

Niobium has no known biological role. While niobium dust is an eye and skin irritant and a potential fire hazard, elemental niobium on a larger scale is physiologically inert (and thus hypoallergenic) and harmless. It is frequently used in jewelry and has been tested for use in some medical implants.[76][77]

Niobium-containing compounds are rarely encountered by most people, but some are toxic and should be treated with care. The short and long term exposure to niobates and niobium chloride, two chemicals that are water soluble, have been tested in rats. Rats treated with a single injection of niobium pentachloride or niobates show a median lethal dose (LD50) between 10 and 100 mg/kg.[78][79][80] For oral administration the toxicity is lower; a study with rats yielded a LD50 after seven days of 940 mg/kg.[78]

[edit] References

  1. ^ Hatchett, Charles (1802). "Eigenschaften und chemisches Verhalten des von Charlesw Hatchett entdeckten neuen Metalls, Columbium" (in German). Annalen der Physik 11 (5): 120–122. doi:10.1002/andp.18020110507. 
  2. ^ Griffith, William P.; Morris, Peter J. T. (2003). "Charles Hatchett FRS (1765-1847), Chemist and Discoverer of Niobium". Notes and Records of the Royal Society of London 57 (3): 299. doi:10.1098/rsnr.2003.0216. http://www.jstor.org/stable/3557720
  3. ^ a b Noyes, William Albert (1918). A Textbook of Chemistry. H. Holt & Co. p. 523. http://books.google.com/?id=UupHAAAAIAAJ&pg=PA523&dq=columbium+discovered+by+Hatchett+was+a+mixture+of+two+elements
  4. ^ a b Wollaston, William Hyde (1809). "On the Identity of Columbium and Tantalum". Philosophical Transactions of the Royal Society of London 99: 246–252. doi:10.1098/rstl.1809.0017. http://www.jstor.org/stable/107264
  5. ^ Rose, Heinrich (1844). "Ueber die Zusammensetzung der Tantalite und ein im Tantalite von Baiern enthaltenes neues Metall" (in German). Annalen der Physik 139 (10): 317–341. doi:10.1002/andp.18441391006. http://gallica.bnf.fr/ark:/12148/bpt6k15148n/f327.table
  6. ^ Rose, Heinrich (1847). "Ueber die Säure im Columbit von Nordamérika" (in German). Annalen der Physik 146 (4): 572–577. doi:10.1002/andp.18471460410. http://gallica.bnf.fr/ark:/12148/bpt6k15155x/f586.table
  7. ^ Kobell, V. (1860). "Ueber eine eigenthümliche Säure, Diansäure, in der Gruppe der Tantal- und Niob- verbindungen". Journal für Praktische Chemie 79 (1): 291–303. doi:10.1002/prac.18600790145. 
  8. ^ a b c Marignac, Blomstrand, H. Deville, L. Troost und R. Hermann (1866). "Tantalsäure, Niobsäure, (Ilmensäure) und Titansäure". Fresenius' Journal of Analytical Chemistry 5 (1): 384–389. doi:10.1007/BF01302537. 
  9. ^ a b c d e Gupta, C. K.; Suri, A. K. (1994). Extractive Metallurgy of Niobium. CRC Press. pp. 1–16. ISBN 0849360714. 
  10. ^ Marignac, M. C. (1866). "Recherches sur les combinaisons du niobium" (in French). Annales de chimie et de physique 4 (8): 7–75. http://gallica.bnf.fr/ark:/12148/bpt6k34818t/f4.table
  11. ^ Hermann, R. (1871). "Fortgesetzte Untersuchungen über die Verbindungen von Ilmenium und Niobium, sowie über die Zusammensetzung der Niobmineralien (Further research about the compounds of ilmenium and niobium, as well as the composition of niobium minerals)" (in German). Journal für Praktische Chemie 3 (1): 373–427. doi:10.1002/prac.18710030137. 
  12. ^ "Niobium". Universidade de Coimbra. http://nautilus.fis.uc.pt/st2.5/scenes-e/elem/e04100.html. Retrieved 2008-09-05. 
  13. ^ Geballe et al. (1993) gives a critical point at currents of 150 kiloamperes and magnetic fields of 8.8 tesla.
  14. ^ a b Geballe, Theodore H. (October 1993). "Superconductivity: From Physics to Technology" (PDF). Physics Today 46 (10): 52–56. doi:10.1063/1.881384. 
  15. ^ Matthias, B. T.; Geballe, T. H.; Geller, S.; Corenzwit, E. (1954). "Superconductivity of Nb3Sn". Physical Review 95: 1435–1435. doi:10.1103/PhysRev.95.1435. 
  16. ^ Kòrösy, F. (1939). "Reaction of Tantalum, Columbium and Vanadium with Iodine". Journal of the American Chemical Society 61 (4): 838–843. doi:10.1021/ja01873a018. 
  17. ^ Ikenberry, Luther; Martin, J. L.; Boyer, W. J. (1953). "Photometric Determination of Columbium, Tungsten, and Tantalum in Stainless Steels". Analytical Chemistry 25 (9): 1340–1344. doi:10.1021/ac60081a011. 
  18. ^ a b c Rayner-Canham, Geoff; Zheng, Zheng (2008). "Naming elements after scientists: an account of a controversy". Foundations of Chemistry 10 (1): 13–18. doi:10.1007/s10698-007-9042-1. 
  19. ^ Clarke, F. W. (1914). "Columbium Versus Niobium". Science 39 (995): 139–140. doi:10.1126/science.39.995.139. PMID 17780662. http://www.jstor.org/stable/1640945
  20. ^ a b c d e Patel, Zh.; Khul'ka K. (2001). "Niobium for Steelmaking" (PDF). Metallurgist 45 (11–12): 477–480. doi:10.1023/A:1014897029026. 
  21. ^ Norman N., Greenwood (2003). "Vanadium to dubnium: from confusion through clarity to complexity". Catalysis Today 78 (1–4): 5–11. doi:10.1016/S0920-5861(02)00318-8. 
  22. ^ a b Peiniger, M.; Piel, H. (1985). "A Superconducting Nb3Sn Coated Multicell Accelerating Cavity". Nuclear Science 32 (5): 3610. doi:10.1109/TNS.1985.4334443. 
  23. ^ Salles Moura, Hernane R.; Louremjo de Moura, Louremjo (2007). "Melting And Purification Of Niobium". AIP Conference Proceedings (American Institute of Physics) (927(Single Crystal - Large Grain Niobium Technology)): 165–178. ISSN 0094-243X. http://link.aip.org/link/?APCPCS%2F927%2F165%2F1
  24. ^ a b c d e f g h Nowak, Izabela; Ziolek, Maria (1999). "Niobium Compounds: Preparation, Characterization, and Application in Heterogeneous Catalysis". Chemical Reviews 99 (12): 3603–3624. doi:10.1021/cr9800208. PMID 11849031. 
  25. ^ Jahnke, L.P.; Frank, R.G.; Redden, T.K. (1960). "Columbium Alloys Today". Metal Progr. 77 (6): 69–74. http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=4183692
  26. ^ Nikulina, A. V. (2003). "Zirconium-Niobium Alloys for Core Elements of Pressurized Water Reactors". Metal Science and Heat Treatment 45 (7–8): 287–292. doi:10.1023/A:1027388503837. 
  27. ^ Lide, David R. (2004). "The Elements". CRC Handbook of Chemistry and Physics (85 ed.). CRC Press. pp. 4–21. ISBN 9780849304859. 
  28. ^ a b c Georges, Audi (2003). "The NUBASE Evaluation of Nuclear and Decay Properties". Nuclear Physics A (Atomic Mass Data Center) 729: 3–128. doi:10.1016/j.nuclphysa.2003.11.001. 
  29. ^ Emsley, John (2001). "Niobium". Nature's Building Blocks: An A-Z Guide to the Elements. Oxford, England, UK: Oxford University Press. pp. 283–286. ISBN 0198503407. 
  30. ^ a b c d Soisson, Donald J.; McLafferty, J. J.; Pierret, James A. (1961). "Staff-Industry Collaborative Report: Tantalum and Niobium". Industrial and Engineering Chemistry 53 (11): 861–868. doi:10.1021/ie50623a016. 
  31. ^ Lumpkin, Gregory R.; Ewing, Rodney C. (1995). "Geochemical alteration of pyrochlore group minerals: Pyrochlore subgroup". American Mineralogist 80: 732–743. http://www.minsocam.org/msa/AmMin/TOC/Articles_Free/1995/Lumpkin_p732-743_95.pdf
  32. ^ a b c Kouptsidis, J; Peters, F.; Proch, D.; Singer, W.. "Niob für TESLA" (in German). Deutsches Elektronen-Synchrotron DESY. http://tesla.desy.de/new_pages/TESLA_Reports/2001/pdf_files/tesla2001-27.pdf. Retrieved 2008-09-02. 
  33. ^ a b c d e f g Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils; (1985). "Niob" (in German). Lehrbuch der Anorganischen Chemie (91–100 ed.). Walter de Gruyter. pp. 1075–1079. ISBN 3110075113. 
  34. ^ Tither, Geoffrey (2001). Minerals, Metals and Materials Society, Metals and Materials Society Minerals. ed. "Progress in Niobium Markets and Technology 1981–2001" (pdf). Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) (Niobium 2001 Ltd, 2002). ISBN 9780971206809. http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/images/pdfs/oppening.pdf
  35. ^ Dufresne, Claude; Goyette, Ghislain (2001). Minerals, Metals and Materials Society, Metals and Materials Society Minerals. ed. "The Production of Ferroniobium at the Niobec mine 1981–2001" (pdf). Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) (Niobium 2001 Ltd, 2002). ISBN 9780971206809. http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_1/images/pdfs/start.pdf
  36. ^ a b Agulyansky, Anatoly (2004). The Chemistry of Tantalum and Niobium Fluoride Compounds. Elsevier. pp. 1–11. ISBN 9780444516046. 
  37. ^ Choudhury, Alok; Hengsberger, Eckart (1992). "Electron Beam Melting and Refining of Metals and Alloys". The Iron and Steel Institute of Japan International 32 (5): 673–681. doi:10.2355/isijinternational.32.673. 
  38. ^ Papp, John F. "Niobium (Columbium)". USGS 2006 Commodity Summary. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/colummcs06.pdf. Retrieved 2008-11-20. 
  39. ^ a b Papp, John F. "Niobium (Columbium)". USGS 2007 Commodity Summary. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/colummcs07.pdf. Retrieved 2008-11-20. 
  40. ^ Papp, John F. "Niobium (Columbium)". USGS 1997 Commodity Summary. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/230397.pdf. Retrieved 2008-11-20. 
  41. ^ Greenwood, Norman N.; Earnshaw, Alan. (1997), Chemistry of the Elements (2nd ed.), Oxford: Butterworth-Heinemann, ISBN 0080379419 
  42. ^ Cardarelli, Francois (2008). Materials Handbook. Springer London. ISBN 978-1-84628-668-1. 
  43. ^ C. R. Lucas, J. A. Labinger, J. Schwartz (1990). Robert J. Angelici. ed. "Dichlorobis(η5-Cyclopentadienyl)Niobium(IV)". Inorganic Syntheses (New York: J. Wiley & Sons) 28: 267–270. doi:10.1002/9780470132593.ch68. ISBN 0-471-52619-3. 
  44. ^ Greenwood, Norman N.; Earnshaw, Alan. (1997), Chemistry of the Elements (2nd ed.), Oxford: Butterworth-Heinemann, ISBN 0080379419 
  45. ^ Verevkin, A.; Pearlman, A.; Slstrokysz, W.; Zhang, J.; Currie, M.; Korneev, A.; Chulkova, G.; Okunev, O.; Kouminov, P.; Smirnov, K.; Voronov, B.; N. Gol'tsman, G.; Sobolewski, Roman (2004). "Ultrafast superconducting single-photon detectors for near-infrared-wavelength quantum communications". Journal of Modern Optics 51 (12): 1447–1458. doi:10.1080/09500340410001670866. 
  46. ^ a b Papp, John F. "Niobium (Columbium ) and Tantalum". USGS 2006 Minerals Yearbook. http://minerals.usgs.gov/minerals/pubs/commodity/niobium/myb1-2006-niobi.pdf. Retrieved 2008-09-03. 
  47. ^ a b Heisterkamp, Friedrich; Tadeu Carneiro (2001). Minerals, Metals and Materials Society, Metals and Materials Society Minerals. ed. "Niobium: Future Possibilities – Technology and the Market Place" (pdf). Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) (Niobium 2001 Ltd, 2002). ISBN 9780971206809. http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/images/pdfs/closing.pdf
  48. ^ Eggert, Peter; Priem, Joachim; Wettig, Eberhard (1982). "Niobium: a steel additive with a future" (PDF). Economic Bulletin 19 (9): 8–11. doi:10.1007/BF02227064. 
  49. ^ Hillenbrand, Hans–Georg; Gräf, Michael; Kalwa, Christoph (2001-05-02). "Development and Production of High Strength Pipeline Steels". Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) (Europipe). http://www.europipe.com/files/ep_tp_43_01en.pdf
  50. ^ Donachie, Matthew J. (2002). Superalloys: A Technical Guide. ASM International. pp. 29–30. ISBN 9780871707499. 
  51. ^ Bhadeshia, H. K. D. H. "Nickel Based Superalloys". University of Cambridge. http://www.msm.cam.ac.uk/phase-trans/2003/Superalloys/superalloys.html. Retrieved 2008-09-04. 
  52. ^ Pottlacher, G.; Hosaeus, H.; Wilthan, B.; Kaschnitz, E.; Seifter, A. (2002). "Thermophysikalische Eigenschaften von festem und flüssigem Inconel 718" (in German). Thermochimica Acta 382 (1–-2): 55–267. doi:10.1016/S0040-6031(01)00751-1. 
  53. ^ a b Hebda, John (2001-05-02). "Niobium alloys and high Temperature Applications" (pdf). Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) (Companhia Brasileira de Metalurgia e Mineração). http://www.cbmm.com.br/portug/sources/techlib/science_techno/table_content/sub_3/images/pdfs/016.pdf
  54. ^ Lindenhovius, J.L.H.; Hornsveld, E.M.; Den Ouden, A.; Wessel, W.A.J.; Ten Kate, H.H.J. (2000). "Powder-in-tube (PIT) Nb/sub 3/Sn conductors for high-field magnets". IEEE Transactions on Applied Superconductivity 10: 975–978. doi:10.1109/77.828394. 
  55. ^ Nave, Carl R. "Superconducting Magnets". Georgia State University, Department of Physics and Astronomy. http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/scmag.html. Retrieved 2008-11-25. 
  56. ^ Glowacki, B. A.; Yan, X. -Y.; Fray, D.; Chen, G.; Majoros, M.; Shi, Y. (2002). "Niobium based intermetallics as a source of high-current/high magnetic field superconductors". Physica C: Superconductivity 372–376 (3): 1315–1320. doi:10.1016/S0921-4534(02)01018-3. 
  57. ^ Grunblatt, G.; Mocaer, P.; Verwaerde Ch.; Kohler, C. (2005). "A success story: LHC cable production at ALSTOM-MSA". Fusion Engineering and Design (Proceedings of the 23rd Symposium of Fusion Technology) 75–79: 1–5. doi:10.1016/j.fusengdes.2005.06.216. 
  58. ^ Lilje, L.; Kakob, E.; Kostina, D.; Matheisena, A.; Möllera, W. -D.; Procha, D.; Reschkea, D.; Saitob, K. Schmüserc, P.; Simrocka, S.; Suzukid T.; Twarowskia, K. (2004). "Achievement of 35 MV/m in the superconducting nine-cell cavities for TESLA". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 524 (1-3): 1–12. doi:10.1016/j.nima.2004.01.045. 
  59. ^ Cherednichenko, Sergey; Drakinskiy, Vladimir; Berg, Therese; Khosropanah, Pourya; Kollberg, Erik (2008). "A Hot-electron bolometer terahertz mixers for the Herschel Space Observatory". Review of Scientific Instruments 79 (3): 0345011–03451010. doi:10.1063/1.2890099. PMID 18377032. 
  60. ^ Volk, Tatyana; Wohlecke, Manfred (2008). Lithium Niobate: Defects, Photorefraction and Ferroelectric Switching. Springer. pp. 1–9. ISBN 9783540707653. 
  61. ^ Pozdeev, Y. (1991). "Reliability comparison of tantalum and niobium solid electrolytic capacitors". Quality and Reliability Engineering International 14 (2): 79–82. doi:10.1002/(SICI)1099-1638(199803/04)14:2<79::AID-QRE163>3.0.CO;2-Y. 
  62. ^ Mallela, Venkateswara Sarma; Ilankumaran, V.; Srinivasa Rao, N. (1 January 2004). "Trends in Cardiac Pacemaker Batteries" (PDF). Indian Pacing Electrophysiol J. 4 (4): 201–212. PMID 16943934. PMC 1502062. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1502062
  63. ^ Godley, Reut; Starosvetsky, David; Gotman, Irena (2004). "Bonelike apatite formation on niobium metal treated in aqueous NaOH" (PDF). Journal of Materials Science: Materials in Medicine 15 (10): 1073–1077. doi:10.1023/B:JMSM.0000046388.07961.81. PMID 15516867. http://www.springerlink.com/content/l5613670648017wp/
  64. ^ Biason Gomes, M. A.; Onofre, S.; Juanto, S.; Bulhões, L. O. de S. (1991). "Anodization of niobium in sulphuric acid media". Journal of Applied Electrochemistry 21 (11): 1023–1026. doi:10.1007/BF01077589. 
  65. ^ Chiou, Y. L. (1971). "A note on the thicknesses of anodized niobium oxide films". Thin Solid Films 8 (4): R37–R39. doi:10.1016/0040-6090(71)90027-7. 
  66. ^ Azevedo, C. R. F.; Spera, G.; Silva, A. P. (2002). "Characterization of metallic piercings that caused adverse reactions during use". Journal of Failure Analysis and Prevention 2 (4): 47–53. doi:10.1361/152981502770351860. http://www.springerlink.com/content/575x64408lnk560j/
  67. ^ Grill, Robert; Gnadenberge, Alfred (2006). "Niobium as mint metal: Production–properties–processing". International Journal of Refractory Metals and Hard Materials 24 (4): 275–282. doi:10.1016/j.ijrmhm.2005.10.008. 
  68. ^ "25 Euro - 150 Years Semmering Alpine Railway (2004)". Austrian Mint. http://austrian-mint.at/bimetallmuenzen?l=en&muenzeSubTypeId=113&muenzeId=217. Retrieved 2008-11-04. 
  69. ^ "150 Jahre Semmeringbahn" (in German). Austrian Mint. http://www.austrian-mint.at/cms/download.php?downloadId=131. Retrieved 2008-09-04. 
  70. ^ "Coin of Time". Bank of Latvia. http://www.bank.lv/eng/main/all/lvnaud/jubmon/nmp/time/. Retrieved 2008-09-19. 
  71. ^ "Coin of Time II". Bank of Latvia. http://www.bank.lv/eng/main/all/lvnaud/jubmon/nmp/time2/. Retrieved 2008-09-19. 
  72. ^ Henderson, Stanley Thomas; Marsden, Alfred Michael; Hewitt, Harry (1972). Lamps and Lighting. Edward Arnold Press. pp. 244–245. ISBN 0-7131-3267-1. 
  73. ^ Eichelbrönner, G. (1998). "Refractory metals: crucial components for light sources" (PDF). International Journal of Refractory Metals and Hard Materials 16 (1): 5–11. doi:10.1016/S0263-4368(98)00009-2. 
  74. ^ Michaluk, Christopher A.; Huber, Louis E.; Ford, Robert B. (2001). Minerals, Metals and Materials Society, Metals and Materials Society Minerals. ed. "Niobium and Niobium 1% Zirconium for High Pressure Sodium (HPS) Discharge Lamps". Niobium Science & Technology: Proceedings of the International Symposium Niobium 2001 (Orlando, Florida, USA) (Niobium 2001 Ltd, 2002). ISBN 9780971206809. 
  75. ^ US patent 5254836, Okada, Yuuji; Kobayashi, Toshihiko; Sasabe, Hiroshi; Aoki, Yoshimitsu; Nishizawa, Makoto; Endo, Shunji, "Method of arc welding with a ferrite stainless steel welding rod", issued 1993-10-19 
  76. ^ Vilaplana, J.; Romaguera, C.; Grimalt, F.; Cornellana, F. (1990). "New trends in the use of metals in jewellery". Contact Dermatitis 25 (3): 145–148. doi:10.1111/j.1600-0536.1991.tb01819.x. PMID 1782765. 
  77. ^ Vilaplana, J.; Romaguera, C. (1998). "New developments in jewellery and dental materials". Contact Dermatitis 39 (2): 55–57. doi:10.1111/j.1600-0536.1998.tb05832.x. PMID 9746182. 
  78. ^ a b Haley, Thomas J.; Komesu, N.; Raymond, K. (1962). "Pharmacology and toxicology of niobium chloride". Toxicology and Applied Pharmacology 4 (3): 385–392. doi:10.1016/0041-008X(62)90048-0. 
  79. ^ Downs, William L.; Scott, James K.; Yuile, Charles L.; Caruso, Frank S.; Wong, Lawrence C. K. (1965). "The Toxicity of Niobium Salts". American Industrial Hygiene Association Journal 26 (4): 337–346. doi:10.1080/00028896509342740. PMID 5854670. http://www.informaworld.com/smpp/content~content=a789022664~db=all
  80. ^ Schroeder, Henry A.; Mitchener, Marian; Nason, Alexis P. (1 January 1970). "Zirconium, Niobium, Antimony, Vanadium and Lead in Rats: Life term studies". Journal of Nutrition 100 (1): 59–68. PMID 5412131. http://jn.nutrition.org/cgi/content/abstract/100/1/59.

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!  

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com/ / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drill、Tapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer. 

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。   

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

 

beeway 發表在 痞客邦 留言(0) 人氣()

1801 年,英國化學家查理斯·哈契特(Charles Hatchett)在一種稱為燒綠石(pyrochlore)的礦物中發現了鈮,由於鈮和鉭非常相似,起初他還曾將兩者混淆,他將這種物質暫命名為 「鈳」。1809年,另一位英國化學家威廉·海德·伍拉斯頓(William Hyde Wollaston)錯誤的將「鉭」與「鈳」歸為同一種物質。1846年,一位德國化學家亨烈赫·羅沙(Heinrich Rose)提出鉭礦里應該還含有另一種元素,並命名為「鈮」。到1864至65年間,一些科研成果表明其實「鈳」與「鈮」是同一種元素,在之後的一個世紀 里,這兩種稱法是通用的。直至1949年,這種元素才被正式定名為「鈮」。因為人們曾長期用鈮鐵礦的名字(Columbium,譯作)來稱呼鈮,所以現在偶爾還會聽到該名稱。

[編輯] 鈮的化學性質

鈮 的化學性質在很多方面跟同族(第5族,即VB族)的前面的元素相似。高溫下,鈮會跟絕大多數非金屬單質反應:室溫即與氟單質反應,200 °C即與氯氣和 氫氣反應,400 °C與氮氣反應,產物通常是填隙式且不是整比化合物。鈮置於空氣中200 °C開始被氧化,卻能夠抵抗熔融鹼金屬和酸(包括王水、鹽 酸、硫酸、硝酸和磷酸等)的腐蝕。鈮能被熱的,濃的無機酸腐蝕,包括氫氟酸或氫氟酸/硝酸混合酸。儘管鈮能顯示出所有正常的氧化態(從+5到−1),其最 穩定的價態為+5價。

鈮能夠形成+5價氧化物五氧化二鈮(Nb2O5),+4價的二氧化鈮(NbO2)還有+3價的三氧化二鈮 (Nb2O3)和較為罕見的氧化態+2價的一氧化鈮(NbO)。 最穩定的氧化態為+5,五氧化物跟非整比的二氧化物是最常見的鈮氧化物。鈮的五氧化物主要用於生產電容器,光學玻璃,或作為製備鈮的其他化合物的起始材 料。製備這些化合物,我們可以將其五氧化二物溶解在鹼性氫氧化物溶液中,或是將之與其他金屬的氧化物共同熔融。例如製備鈮酸鋰(LiNbO3)、鈮酸鑭 (LaNbO4)。對於鈮酸鋰的結構,鈮酸根離子(NbO3−)不是作為單體存在,而是三角形扭曲的鈣鈦礦結構的一部分,而對於鈮酸鑭的結構則包含孤立的 NbO4−離子。鈮酸鋰作為一種鐵電物質,被廣泛應用於手機和光調製器,以及聲表面波器件的生產,屬於ABO3結構類似鉭酸鋰和鉭酸鋇的鐵電體。

鈮 能夠形成+5,+4,+3價鹵化物(NbX5,NbX4和NbX3),也能生成多核配合物和非整比化合物。五氟化鈮(NbF5)為白色固體,熔點 79.0 °C;五氯化鈮(NbCl5)是黃白色固體,熔點203.4 °C。兩者都能發生水解反應,在高溫條件下能夠與過量的鈮單質反應,生成黑色極易 潮解的四氟化鈮(NbF4)和四氯化鈮(NbCl4)。鈮的三鹵化物能夠通過氫氣還原其五鹵化物製得,而其二鹵化物則不存在。高溫下一氯化鈮的光譜能夠被 檢測到。鈮的氟化物可用於分離鈮和鉭的混合物。五氯化鈮在有機化學中被用作觸發烯烴的Diels-Alder反應的Lewis酸。五氯化鈮還能作為原料製 備有機金屬化合物二氯二茂鈮((C5H5)2NbCl2),可作為製備其它有機鈮化合物的起始原料。其他二元化合物如氮化鈮(NbN)在低溫條件下顯示出 超導性,現已用於紅外探測器;碳化鈮則是一種硬度很大的,熔點很高的陶瓷材料,在製造商品上用於製造切割工具的一部分。鍺化鈮(Nb3Ge),錫化鈮 (Nb3Sn)還有鈮鈦合金,都被用作超導磁體的超導導線。其它的化合物有硫化鈮和其它幾種鈮的填隙型化合物,如鈮跟硅的填隙型化合物等,此處不再細說。

 



引用出處: 

 http://zh.wikipedia.org/zh-hk/%E9%93%8C

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!  

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com/ / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drillTapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer. 

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。   

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

 

beeway 發表在 痞客邦 留言(0) 人氣()

来源: 阿里巴巴冶金资讯 稀有金属钽和铌在元素周期表中属于同族元素,由于它们的物理和化学性质很相似,而且又共同生长在同一个矿体内,因而被人们称为金属中的"孪生兄弟"。 

 

    钽和铌是英国化学家查尔斯·哈切特与瑞典化学家艾克贝格在1801年和1802年先后发现的。钽铌铁矿是钽和铌的主要矿石,在钨矿和某些稀土矿中也有少量 的钽和铌存在。钽却呈银白色,铌的外表很象钢。钽和铌都是高熔点金属,它们的熔点分别为2996℃和2468℃。钽和铌的化学性质极其稳定,不仅不怕硝 酸、盐酸,也不怕王水。钽富有延展性,可以拉成比头发丝还要细的钽丝,或者碾成比纸还要薄的钽箔。钽和铌都具有抗压、耐磨损的特性,也都是卓越的超导材 料。 

 

    由于钽和铌具有上述种种优异的性能,因而被广泛用于各个领域。

 

    钽的表面能形成致密稳定、介电强度高的无定形氧化膜,易于准确方便地控制电容器的阳极氧化工艺,同时钽粉烧结块可以在很小的体积内获得很大的表面积,因此 钽电容器体积小、容量大、漏电流低、使用寿命长、综合性能优异,是最优秀的电容器, 不仅在常规条件下比陶瓷、铝、薄膜等其它电容器体积小、容量高、功能稳定,而且能在许多为其它电容器所不能胜任的严峻条件下正常工作。由于钽电容器具有其 它诸多电容器不可比拟的优异特性,在微电子科学和表面贴装技术领域,几乎无可等效替代的其它电容器与之竞争,因此60~65%的钽以电容器级钽粉和钽丝的 形式用于制作钽电容器。钽电容器已日益广泛应用于通讯(程控机、交换机、手机、传呼机、传真机、无绳电话)、计算机、汽车、家用和办公用电器、 仪器仪表、航天航空、国防军工等领域.由于铌与钽是同属一族的伴生金属,性能上有许多相似之处,用于制作电容器性能仅次于钽,其相对于铝电容器,具有比容 高、等效串联电阻低、易于片式化等优点,经发展有可能替代铝电容器的10%左右;铌与钽相比,制作电容器的主要缺点是漏电流大(一般是钽的5~10倍)、 击穿电压低(<10V)、工作温度低(<105℃),不适合制作可靠性要求高和额定电压 

 

    高的电容器,但在低电压(<10V)、大容量(>100μF)的范围,铌电容器有可能部分替代该档次的钽电容器。铌电容器的开发利用,对钽铌行业来说是一件大好事,可以获得新的发展机遇。 

 

    近十年来,我国钽铌冶炼与加工也 取得了突破性的发展。各钽铌冶炼厂(院),加强了科研工作,进行了技术改造,不断完善工艺和装备,调整了产品结构,开发新产品,使产品质量大大提高。宁夏 东方有色金属集团公司从1990年开始先后进行了钽粉、钽丝生产技术改造,引进了国外关键装备,使钽粉及钽丝的生产技术大大提高了一步,钽粉比容达到了 12000~30000~50000~70000μFV/g,研制水平达150000μFV/g。钽丝生产达到了直径Φ0.3~0.17mm,研究水平已 达到Φ0.10mm,我国的钽粉、钽丝质量水平已达到了国际水平。 

 

    在冶金工业中,铌主要用于制造耐高温的合金钢和提高钢的强度。在冶炼碳素钢时,只需添加万分之几的铌,便可以使钢的强度提高三分之一以L。用铌和钽与钨、铝、镍、钴、钒等一系列金属合成的超级合金,是超音速喷气式飞机、火箭和导弹等的良好结构材料。 

 

    在机械工业中,用碳化铌、碳化钽等硬质合金制造的刀具,能经受近3000℃的高温,其硬度可以与世界上最坚硬的物质---金刚石相媲美。 

 

    在医学上,钽是理想的生物适应性材料。它与人体的骨骼、肌肉组织以及液体直接接触时,能够与生物细胞相适应,具有极好的亲和性,几乎不对人体产生刺激和副 作用。钽不仅可用于制作治疗骨折用的接骨板、螺钉、夹杆等,而且可以直接用钽板、钽片修补骨头和用钽条来代替因外伤而折断的骨头。钽丝和钽箔可以缝合神 经、肌健以及1.5毫米以上的血管,极细的钽丝可以代替肌腱甚至神经纤维。用钽丝织成的钽纱、钽网可以用来修补肌肉组织。 

 

引用出處: 

 http://info.china.alibaba.com/news/detail/v6-d5632469.html

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!  

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com/ / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drillTapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer.

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。   

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz.

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

 

beeway 發表在 痞客邦 留言(0) 人氣()

钽:原子序数 73,原子量180.9479,元素名来源于古希腊神话中宙斯之子的名字。1802年瑞典化学家厄克贝里再钽铁矿中发现这一元素,1903年俄国化学家博 尔顿分离出纯钽。钽是一种稀有金属,在地壳中的含量为0.0002%,在自然界中常与铌共存。主要矿物有钽铁矿、细晶石等。钽有两种天然同位素:钽 180、181。

纠错  编辑摘要

目录

  • 1 概述
  • 2 性质
  • 3 发现
  • 4 特性
  • 5 性质
  •  

  • 1 概述
  • 2 性质
  • 3 发现
  • 4 特性
  • 5 性质
  • 6 资源
  • 7 制取
  • 8 用途
  • 9 钽合金
  • 10 参考资料

 

 

钽 - 概述

 

钽为黑灰色金属,有延展性,熔点2996°C,沸点5425°C,密度16.6克/厘米³,金属钽具有体心立方结构。

钽 的化学性质特别稳定,常温下除氢氟酸外不受其它无机酸碱的侵蚀;高温下能溶于浓硫酸、浓磷酸和强碱溶液中;金属钽在氧气流中强烈灼烧可得五氧化二钽;常温 下能与氟反应;高温下能与氯、硫、氮、碳等单质直接化合。钽最早用于制灯丝,后被钨丝代替;化学工业中钽用于制造耐酸设备;由于钽不被人体排斥,可用作修 复骨折所需的金属板、螺钉等,还用于制造外科刀具和人造纤维的拉线模等。

 

钽 - 性质

 

元素符号: Ta

原子序数: 73

相对原子质量:(12C = 12.0000)

 

原子体积:(立方厘米/摩尔):0.90

元素在海水中的含量:(ppm):.000002

地壳中含量:(ppm):2

氧化态:Main  Ta+5

Other  Ta-3, Ta-1, Ta+1, Ta+2, Ta+3, Ta+6

晶体结构:晶胞为体心立方晶胞,每个晶胞含有2个金属原子。

 

晶胞参数:

a = 330.13 pm

b = 330.13 pm

c = 330.13 pm

α = 90°

β = 90°

γ = 90°

 

莫氏硬度:6.5

声音在其中的传播速率:(m/S) 3400

 

电离能 (kJ /mol) 

M - M+ 761

M+ - M2+ 1500

M2+ - M3+ 2100

M3+ - M4+ 3200

M4+ - M5+ 4300

 

钽 - 发现

 

发现人:1802年由AG Ekeberg (瑞典,乌普萨拉)发现。

来源:主要存在于钽铁矿中,同铌共生。

钽 是由瑞典化学家埃克贝里(A.G.Ekeberg)在1802年发现的,按希腊神话人物Tantalus(坦塔罗斯)的名字命名为tantalum。 1903年德国化学家博尔顿(W.von Bolton)首次制备了塑性金属钽,用作灯丝材料。1940年大容量的钽电容器出现,并在军用通信中广泛应用。第二次世界大战期间,钽的需要量剧增。 50年代以后,由于钽在电容器、高温合金、化工和原子能工业中的应用不断扩大,需要量逐年上升,促进了钽的提取工艺的研究和生产的发展。中国于60年代初 期建立了钽的冶金工业。

 

钽 - 特性

钽的质地十分坚硬,硬度可以达到6-6.5。它的熔点高达2996℃  ,仅次于钨和铼,位居第三。钽富有延展性,可以拉成细丝式制薄箔。其热膨胀系数很小,每升高一摄氏度只膨胀百分之六点六。除此之外,它的韧性很强,比铜还要优异。

钽 还有非常出色的化学性质,具有极高的抗腐蚀性。无论是在冷和热的条件下,对盐酸、浓硝酸及“王水”都不反应。将钽放入200℃的硫酸中浸泡一年,表层仅损 伤0.006毫米。实验证明,钽在常温下,对碱溶液、氯气、溴水、稀硫酸以及其他许多药剂均不起作用,仅在氢氟和热浓硫酸作用下有所反应。这样的情况在金 属中是比较罕见的。钽所具有的特性,使它的应用领域十分广阔。在制取各种无机酸的设备中,钽可用来替代不锈钢,寿命可比不锈钢提高几十倍。此外,在化工、 电子、电气等工业中,钽可以取代过去需要由贵重金属铂承担的任务,使所需费用大大降低。  钽被制造成了电容装备到军用设备中。美国的军事工业异常发达,是世界最大军火出口商。世界上钽金属的产量一半被用在钽电容的生产上,美国国防部后勤署则是 钽金属最大的拥有者,曾一度买断了世界上三分之一的钽粉。

 

钽 - 性质

钽 在低于150℃的条件下,是化学性质最稳定的金属之一。与钽能起反应的只有氟、氢氟酸、含氟离子的 酸性溶液和三氧化硫。在室温下与浓碱溶液反应,并且溶于熔融碱中。致密的钽在200℃开始轻微氧化,在280℃时明显氧化。钽有多种氧化物,最稳定的是五 氧化二钽。钽和氢在250℃以上生成脆性固溶体和金属氢化物。在800-1200℃的真空下,氢从钽中析出,钽又恢复塑性。钽和氮在300℃左右开始反应 生成固溶体和氮化合物;在高于2000℃和高真空下,被吸收的氮又从钽中析出。钽与碳在高于2800℃下以三种物相存在:碳钽固溶体、低价碳化物和高价碳 化物。钽在室温下能与氟反应,在高于250℃时能与其他卤素反应,生成卤化物。

 

钽 - 资源

钽 和铌的物理化学性质相似,故多共生于自然界的矿物中。已查明的世界钽的储量(以钽计)约为134000短吨,扎伊尔占首位。1979年世界钽矿物的产量 (以钽计)为788短吨(1短吨=907.2公斤)。中国钽的储量,1993年为83470吨,当年的产量18.027吨。

 

钽 - 制取

 钽 铌矿中常伴有多种金属,钽冶炼的主要步骤是分解精矿,净化和分离钽、铌,以制取钽、铌的纯化合物,最后制取金属。矿石分解可采用氢氟酸分解法、氢氧化钠熔 融法和氯化法等。钽铌分离可采用溶剂萃取法(常用的萃取剂为甲基异丁酮、磷酸三丁酯、仲辛醇和乙酰胺等)、分步结晶法和离子交换法

 

钽 - 用途

用途:用于金属合金。五氧化钽用于电容器。钽也用于切削工

钽电解电容

具, 真空灯丝,照相机镜头。钽在酸性电解液中形成稳定的阳极氧化膜,用钽制成的电解电容器,具有容量大,体积小和可靠性好等优点,制电容器是钽的最重要用 途,70年代末的用量占钽总用量2/3以上。钽也是制作电子发射管、高功率电子管零件的材料。钽制的抗腐蚀设备可用于生产强酸、溴 、氨等化学工业。

 

金 属钽可作收音机发动机的燃烧室的结构材料。钽钨、钽钨铪、钽铪合金用作火箭、导弹和喷气发动机的耐热高强材料及控制和调节装备的零件等。钽易加工成形,在 高温真空炉中作支撑附件、热屏蔽、加热器和散热片等。钽可作骨科和外科手术材料。碳化钽用于制造硬质合金。钽的硼化物、硅化物和氮化物及其合金用作原子能 工业中的释热元件和液态金属包套材料。氧化钽用于制造高级光学玻璃和催化剂。

 

钽 - 钽合金

 

tantalum alloys ,以钽为基加入其他元素组成的合金。钽的阳极氧化膜很稳定,耐蚀,介电性能优异,适于制造电解电容器。钽抗化学腐蚀能力强,除氟化氢、三氧化硫、氢氟酸、 热浓硫酸和碱外,能抗御一切有机和无机酸的腐蚀,因而可用作化学工业和医学的耐蚀材料。钽的碳化物是制造硬质合金的重要添加剂。此外,钽也用于某些电子管 中。1958年,Ta-10W合金投入生产。20世纪60年代,钽合金作为高温结构材料用于航天工业上。钽和钽合金产品有板材、带材、箔材、棒材、线材、 异型件和烧结制品等。中国在50年代末开始研究钽的冶炼和塑性加工,60年代中期已能生产钽及其合金的制品。

 

合金强 化 在难熔金属中,钽的低温塑性是最好的,它的塑性-脆性转变温度低于-196℃。研制钽合金必须考虑保持钽的优异的低温塑性。钽合金多采用固溶强化的方法, 也采用固溶和沉淀强化相结合的方法来提高强度,在周期表中钽的毗邻元素有的能在钽中完全固溶,有的溶解度很大。强化效果最明显的置换固溶元素是铼、钨、锆 和铪。 加入元素量如超过一定范围,会损害钽的低温塑性。一般认为加入的原子百分比应少于12~14%。间隙元素氮、碳和氧对提高钽的强度效果不大,却使钽的低温 塑性和加工塑性受到明显的损害。这些间隙元素与活性元素锆或铪形成弥散的沉淀相时,才有明显的强化效果。由Ta-10W发展出来的Ta-10W- 2.5Hf-0.01C合金是固溶和沉淀强化相结合的典型合金。钽和几种典型的钽合金的力学性能。

 

坯锭:钽及其合金坯料可 用粉末冶金工艺或 熔炼工艺生产。粉末冶金工艺多用于生产小型钽制品和加工用的坯料。用热还原法或电解法制得的粉末钽原料,经压制成型后进行真空烧结。烧结工艺取决于对产品 的使用要求。一次烧结(1600~2200℃)用于生产熔炼用电极和多孔阳极。二次烧结用于生产锻造、轧制和拉拔等塑性加工用的坯料。两次烧结之间常进行 锻造或轧制,加工率约50%。二次烧结温度为2000~2700℃。

 

真空自耗电弧和电子束熔炼工艺是制取钽及其合金铸

钽丝

锭的常用方法。电子束熔炼工艺主要用于钽的提纯,自耗电弧熔炼工艺可制取大直径和合金成分更均匀的铸锭,自耗电弧熔炼的电极可用烧结棒或电子束熔炼锭制成,熔炼法得到的铸锭晶粒粗大,常需开坯破碎铸态晶粒以提高塑性。为使钽进一步提纯或制备单晶可使用电子束区域熔炼法。

 

塑 性加工 纯钽的塑性良好,变形抗力小,加工硬化率较小,各种型材和异型零部件都可用塑性加工方法制得。纯钽在室温下可轧成板材、带材、箔材、管材和棒材,加工率可 达90%以上。为减轻氧化,纯钽塑性加工常在室温或 500℃以下进行。钽合金由于强度高和铸锭塑性差,须先在1200℃以上进行开坯,以后的加工工艺与纯钽相同。开坯的挤压比应大于4,锻造比应大于2。锭 坯在加热开坯时,要防止气体污染而使材料塑性下降。为保证产品有良好冲压和旋压性能,要用交叉轧制。交叉轧制前的加工率应保持在80%左右。钽板通过旋压 和深冲可制成杯、帽、管、锥体、喷管等不同形状的零件。供拉丝用的旋锻棒直径一般为2.5毫米。由于钽质软,易和模具粘结和划伤表面,拉丝时常先使线材表 面经过阳极氧化形成氧化膜,并用蜂蜡润滑。

焊接:真空电子束焊接和惰性气体保护钨极焊接工艺,可制取塑性-脆性转变温度低的焊件。这种焊 接工艺制得的焊接钽管,可满足化工部门的使用要求。钽还可和不锈钢、钛合金、镍合金和碳钢焊接在一起。用高能率成形(爆炸法)可使钢和钽复合成双金属,是 制造大型耐蚀设备内衬的有效方法。

切削加工:钽和钽合金容易磨损和粘结刀具,宜用高速钢刀具,并用四氯化碳等有机溶剂冷却。磨削加工宜用碳化硅砂轮,因氧化铝砂轮易使磨面龟裂。

热处理:主要有退火和固溶时效处理。为防止大气污染,钽合金的热处理必须在10-4托的真空中或高纯惰性气体中进行,有时甚至需要用钽箔把产品包裹起来。

 

钽 - 参考资料

http://www.cnitdc.com/kepu/kpzc.asp?smallid=35&smallname=%E9%92%BD%EF%BB%BF

歡迎來到Bewise Inc.的世界,首先恭喜您來到這接受新的資訊讓產業更有競爭力,我們是提供專業刀具製造商,應對客戶高品質的刀具需求,我們可以協助客戶滿足您對產業的不同要求,我們有能力達到非常卓越的客戶需求品質,這是現有相關技術無法比擬的,我們成功的滿足了各行各業的要求,包括:精密HSS DIN切削刀具協助客戶設計刀具流程DIN or JIS 鎢鋼切削刀具設計NAS986 NAS965 NAS897 NAS937orNAS907 航太切削刀具,NAS航太刀具設計超高硬度的切削刀具醫療配件刀具設計複合式再研磨機PCD地板專用企口鑽石組合刀具粉末造粒成型機主機版專用頂級電桿PCD V-Cut捨棄式圓鋸片組粉末成型機航空機械鉸刀主機版專用頂級電汽車業刀具設計電子產業鑽石刀具木工產業鑽石刀具銑刀與切斷複合再研磨機銑刀與鑽頭複合再研磨機銑刀與螺絲攻複合再研磨機等等。我們的產品涵蓋了從民生刀具到工業級的刀具設計;從微細刀具到大型刀具;從小型生產到大型量產;全自動整合;我們的技術可提供您連續生產的效能,我們整體的服務及卓越的技術,恭迎您親自體驗!!  

BW Bewise Inc. Willy Chen willy@tool-tool.com  bw@tool-tool.com  www.tool-tool.com skype:willy_chen_bw mobile:0937-618-190 Head &Administration Office No.13,Shiang Shang 2nd St., West Chiu Taichung,Taiwan 40356 http://www.tool-tool.com/ / FAX:+886 4 2471 4839 N.Branch 5F,No.460,Fu Shin North Rd.,Taipei,Taiwan S.Branch No.24,Sec.1,Chia Pu East Rd.,Taipao City,Chiayi Hsien,Taiwan

Welcome to BW tool world! We are an experienced tool maker specialized in cutting tools. We focus on what you need and endeavor to research the best cutter to satisfy users demand. Our customers involve wide range of industries, like mold & die, aerospace, electronic, machinery, etc. We are professional expert in cutting field. We would like to solve every problem from you. Please feel free to contact us, its our pleasure to serve for you. BW product including: cutting toolaerospace tool .HSS  DIN Cutting toolCarbide end millsCarbide cutting toolNAS Cutting toolNAS986 NAS965 NAS897 NAS937orNAS907 Cutting Tools,Carbide end milldisc milling cutter,Aerospace cutting toolhss drillФрезерыCarbide drillHigh speed steelCompound SharpenerMilling cutterINDUCTORS FOR PCD’CVDD(Chemical Vapor Deposition Diamond )’PCBN (Polycrystalline Cubic Boron Nitride) Core drill、Tapered end millsCVD Diamond Tools Inserts’PCD Edge-Beveling Cutter(Golden FingerPCD V-CutterPCD Wood toolsPCD Cutting toolsPCD Circular Saw BladePVDD End Millsdiamond tool. INDUCTORS FOR PCD . POWDER FORMING MACHINE Single Crystal Diamond Metric end millsMiniature end millsСпециальные режущие инструменты Пустотелое сверло Pilot reamerFraisesFresas con mango PCD (Polycrystalline diamond) ‘FresePOWDER FORMING MACHINEElectronics cutterStep drillMetal cutting sawDouble margin drillGun barrelAngle milling cutterCarbide burrsCarbide tipped cutterChamfering toolIC card engraving cutterSide cutterStaple CutterPCD diamond cutter specialized in grooving floorsV-Cut PCD Circular Diamond Tipped Saw Blade with Indexable Insert PCD Diamond Tool Saw Blade with Indexable InsertNAS toolDIN or JIS toolSpecial toolMetal slitting sawsShell end millsSide and face milling cuttersSide chip clearance sawsLong end millsend mill grinderdrill grindersharpenerStub roughing end millsDovetail milling cuttersCarbide slot drillsCarbide torus cuttersAngel carbide end millsCarbide torus cuttersCarbide ball-nosed slot drillsMould cutterTool manufacturer. 

Bewise Inc.  www.tool-tool.com

ようこそBewise Inc.の世界へお越し下さいませ、先ず御目出度たいのは新たな

情報を受け取って頂き、もっと各産業に競争力プラス展開。

弊社は専門なエンドミルの製造メーカーで、客先に色んな分野のニーズ

豊富なパリエーションを満足させ、特にハイテク品質要求にサポート致します。

弊社は各領域に供給できる内容は:

(1)精密HSSエンドミルのR&D

(2)Carbide Cutting tools設計

(3)鎢鋼エンドミル設計

(4)航空エンドミル設計

(5)超高硬度エンドミル

(6)ダイヤモンドエンドミル

(7)医療用品エンドミル設計

(8)自動車部品&材料加工向けエンドミル設計

弊社の製品の供給調達機能は:

(1)生活産業~ハイテク工業までのエンドミル設計

(2)ミクロエンドミル~大型エンドミル供給

(3)小Lot生産~大量発注対応供給

(4)オートメーション整備調達

(5)スポット対応~流れ生産対応

弊社の全般供給体制及び技術自慢の総合専門製造メーカーに貴方のご体験を御待ちしております。     

Bewise Inc. talaşlı imalat sanayinde en fazla kullanılan ve üç eksende (x,y,z) talaş kaldırabilen freze takımlarından olan Parmak Freze imalatçısıdır. Çok geniş ürün yelpazesine sahip olan firmanın başlıca ürünlerini Karbür Parmak Frezeler, Kalıpçı Frezeleri, Kaba Talaş Frezeleri, Konik Alın Frezeler, Köşe Radyüs Frezeler, İki Ağızlı Kısa ve Uzun Küresel Frezeler, İç Bükey Frezeler vb. şeklinde sıralayabiliriz. 

BW специализируется в научных исследованиях и разработках, и снабжаем самым высокотехнологичным карбидовым материалом для поставки режущих / фрезеровочных инструментов для почвы, воздушного пространства и электронной индустрии. В нашу основную продукцию входит твердый карбид / быстрорежущая сталь, а также двигатели, микроэлектрические дрели, IC картонорезальные машины, фрезы для гравирования, режущие пилы, фрезеры-расширители, фрезеры-расширители с резцом, дрели, резаки форм для шлицевого вала / звездочки роликовой цепи, и специальные нано инструменты. Пожалуйста, посетите сайт  www.tool-tool.com  для получения большей информации.

BW is specialized in R&D and sourcing the most advanced carbide material with high-tech coating to supply cutting / milling tool for mould & die, aero space and electronic industry. Our main products include solid carbide / HSS end mills, micro electronic drill, IC card cutter, engraving cutter, shell end mills, cutting saw, reamer, thread reamer, leading drill, involute gear cutter for spur wheel, rack and worm milling cutter, thread milling cutter, form cutters for spline shaft/roller chain sprocket, and special tool, with nano grade. Please visit our web  www.tool-tool.com  for more info.

 

beeway 發表在 痞客邦 留言(0) 人氣()