摘要
本文利用EBSD技术对亚稳β型Ti-25Nb-25Ta合金室温拉伸变形过程中{332}〈113〉变形孪晶的演变趋势及交叉现象进行了研究。结果表明:随着变形量的增大,孪晶宽度不断增加,孪晶形态由变形初期的平直细条带状逐渐变为宽窄不一的条带状,至变形末期部分孪晶呈破碎状,孪晶界严重扭曲变形。多数晶粒内产生两种以上{332}〈113〉孪晶变体,部分孪晶能穿越晶界继续生长,某些初次孪晶内部有二次{332}〈113〉孪晶产生。不同变体孪晶间易发生交叉现象。不同{332}〈113〉孪晶变体的交叉作用导致交叉区域出现较大的局部晶格畸变,晶格畸变主要集中于孪晶内部,且交叉界面处的晶格畸变程度最为严重。交叉作用的结果是交叉区域的晶体相对于不同孪晶变体和基体的取向都发生一定程度的改变。
Electron Backscatter Diffraction(EBSD)technique was applied to investigate the evolution tendency and intersection phenomenon of{332}〈113〉deformation twinning in a metastableβ-type Ti-25Nb-25 Ta alloy tensile deformed at room temperature.Results showed that with the increase of deformation,the thickness of{332}twin lathes increased,and their morphology changed gradually from straight thin to various width.At the final stage of the deformation,some twins were broken with their twin boundaries seriously distorted.With the progress of deformation,two or more types of twinning systems were observed to be activated in most of the grains,and it appeared that some twins could pass through the grain boundaries and continually grew in the neighboring grains.Secondary{332}〈113〉twins were also observed inside the some thicker primary twins.{332}〈113〉twins of different orientational variants could undergo twin-twin intersection frequently,resulting in large local lattice distortion in the intersected zone.The lattice distortion due to the intersection was mainly confined within the twinned structure,and the most heavily distorted zones were in the vicinity of intersection boundaries.As a result of the twinning intersection,the crystal orientation of intersected zone was changed to some extent compared with both the matrix and the twins involved in the intersection.
作者
胡常青
刘翠秀
陈斌
赵颉
黄子坤
孙威
HU Chang-qing;LIU Cui-xiu;CHEN Bin;ZHAO Jie;HUANG Zi-kun;SUN Wei(Institute of Microstructure and Property of Advanced Materials,Beijing University of Technology,Beijing 100124,China)
出处
《电子显微学报》
CAS
CSCD
2016年第5期386-392,共7页
Journal of Chinese Electron Microscopy Society
基金
国家自然科学基金资助项目(No.51171004)
