钽及钽钨合金冷轧变形过程中的组织和性能  

Properties and structure of Ta and Ta-W alloys during cold-rolling process

作　　者：王珊[1] 汪明朴[1] 陈畅[1] 夏福中[1] 左波[1] 张婉[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料热处理学报》2012年第6期58-63,共6页Transactions of Materials and Heat Treatment

基　　金：国家高新技术发展'863'计划资助项目(2006AA03Z517);湖南省自然科学基金(05JJ30095)

摘　　要：通过显微硬度分析、X射线衍射分析和TEM详细研究了钽及钽钨合金在冷轧变形过程中的组织和性能演变规律,结果表明:W在Ta中具有晶粒细化和强化作用,Ta、Ta-2.5%W和Ta-7.5%W合金在1400℃温度退火1 h后的再结晶晶粒的平均尺寸为45、20和15μm;在冷轧过程中,随着变形量的增加,钽和钽钨合金的显微硬度都逐步提高,当变形量达到99%时,Ta、Ta-2.5%W和Ta-7.5%W的显微硬度分别达到了243、309和359 HV;在Ta中添加W后,合金的位错密度会得到极大的提高,其中Ta-7.5%W合金的位错密度比Ta的高一个数量级;钽和钽钨合金各取向的晶粒中的位错密度不同,其中{200}、{211}、{222}和{110}取向的位错密度依次增大,这与Taylor因子计算的结果一致;TEM研究表明,{100}取向的晶粒中形成了位错胞结构,而{110}取向的晶粒中形成了形变带组织。Evolution of properties and structure of Ta and Ta-W alloys in the process of cold rolling were investigated by microhardness analysis, optical microstructure （OM） observation and transmission electron microscopy （TEM）. The results indicate that W has effects on strengthening and grain refinement, and the average grain size of Ta, Ta-2. 5% W and Ta-7.5% W alloys is 45, 20 and 15 ~m, respectively. As increasing of cold-rolling reduction, microhardness of Ta, Ta-2. 5% W and Ta-7.5% W alloys is improved gradually, and reaches the maximun values of 243,309 and 359 HV at reduction of 99% , respectively. The dislocation density of the alloys increases markedly by the addition of W. Especially, compared with pure Ta, Ta-7.5% W alloy is one order of magnitude higher in the density of dislocations. The dislocation density is different in cold-rolled Ta and Ta-W grains with different orientations and is consistent with the relationship 1200t 〈 12111 〈 1222/ 〈 t1101, which is confirmed by the results of calculated Taylor factors. TEM analysis indicates that dislocation ceils form in {100}, while deformation bands form in {110}.

关 键 词：TA-W合金 冷轧 织构 位错结构 

分 类 号：TG146.2[一般工业技术—材料科学与工程]