马氏体相变加速亚稳β钛合金变形晶粒细化（英文）  

Enhanced Grain Refining Efficiency Assisted by Martensitic Transformation in Metastable β-Titanium Alloy

作　　者：陈威[1] 姚姗姗[1] 刘若蕾[1] 孙巧艳[1] 肖林[1] 孙军[1] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049

出　　处：《稀有金属材料与工程》2015年第7期1601-1606,共6页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51301127);National Key Basic Research Program of China('973'Program)(2014CB644002);Natural Science Basic Research Plan in Shaanxi Province of China(2014JQ6205);the Fundamental Research Funds for Central Universities of China(xjj2014126)

摘　　要：利用重复冲击变形技术对比研究了α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。The microstructural evolution and formation mechanism of nanograins in Ti-2Al-2.5Zr α-titanium alloys and Ti-10V-2Fe-3Al metastable β-titanium alloys subjected to multi-impact process at ambient temperature were investigated using optical microscopy, X-ray diffraction and transmission electron microscopy.The results show that deformation twinning, dislocation activities and shear banding successively dominate plastic deformation in Ti-2Al-2.5Zr alloy.In contrast, deformation-induced martensitic phase transformation becomes prevalent in Ti-10V-2Fe-3Al alloy.Martensitic subdivision, shear banding and reverse martensitic transformation contribute to grain refinement.Moreover, nanograins are finally achieved in both titanium alloys at a strain of 1.2, but grain refining efficiency is more significant in Ti-10V-2Fe-3Al alloy.The accelerated grain refinement could be attributed to the assistance of martensitic phase transformation.

关 键 词：钛合金 重复冲击变形 马氏体相变 形变孪生 纳米晶 

分 类 号：TG146.23[一般工业技术—材料科学与工程]