许峰
,
张喜燕
,
程佑铭
稀有金属材料与工程
利用动态塑性变形(DPD)和准静态压缩变形(QSC)技术对纯钛圆柱样品进行对比压缩试验,研究了不同应变速率下纯钛形变孪晶和微结构演变.结果发现:2种变形方式的变形机制相似,低应变时以形变孪生为主,孪生饱和后转变为位错滑移主导;高应变速率促进了形变孪晶的产生,激发{1124}压缩孪晶的形成,同时使变形机制转变临界应变提前至0.2;纯钛在高应变速率和高应变(ε≥0.6)下出现绝热剪切带(ASB).
关键词:
应变速率
,
纯钛
,
变形机制
,
形变孪晶
,
绝热剪切带
陈威
,
姚姗姗
,
刘若蕾
,
孙巧艳
,
肖林
,
孙军
稀有金属材料与工程
利用重复冲击变形技术对比研究了a钛合金Ti-2Al-2.5Zr和亚稳β钛合金Ti-10V-2Fe-3Al变形过程中的微观组织演化及纳米晶的形成机制.金相形貌、X射线衍射及透射电镜观察显示,对于Ti-2Al-2.5Zr合金,塑性变形先后经历了形变孪生、位错活动、剪切等3个过程.与之相反,对于Ti-10V-2Fe-3Al合金,马氏体相变主导着合金的变形.相变分割、剪切及逆向马氏体相变持续贡献于合金的晶粒细化.同时发现,尽管变形到应变量1.2时两类合金组织内均出现纳米晶,但是大量的透射形貌观察显示Ti-10V-2Fe-3Al合金中生成的纳米晶晶粒尺寸更小,纳米晶区域更大.这表明,变形过程中激活马氏体相变可加速材料的晶粒细化.
关键词:
钛合金
,
重复冲击变形
,
马氏体相变
,
形变孪生
,
纳米晶
W Liang~1
,
2)
,
Q. Li~2) and D.ZYang~2)(Centre of Measuring and Testing Taiyuan University of Technology
,
Taiyuan 030024
,
China Institute of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin 150001 China Manuscript received 13 November 1995)
金属学报(英文版)
An in situ study of twinning at crack tip in a TiAl-base alloy has been performed.The result shows that twinning with long shear vector(2/6) [112] can generate on(111) plane, even though usually it is very difficult to occur because of the high energy barrier. It was further shown that (1/6) [112](111) twinning is considerably easier to generate. Furthermore,(1/2)<110) ordinary dislocations were very active and dominated nearly the whole plastic zone, in spite of low Schmid factors. On the other hand, however <101) and (1/2) <112] superdislocations with higher Schmid factors can hardly be observed.
关键词:
:TiAl-base alloy
,
null
,
null
