摘要
研究Y含量对挤压Mg−xY(x=0.5,1,1.5,质量分数,%)板材在沿挤压方向单轴拉伸和压缩下的晶粒尺度孪生行为的影响。基于电子背散射衍射(EBSD),获得大量数据(包括2691个晶粒和977个孪晶),并对其运用自动孪晶变体分析方法。结果表明,无论拉伸还是压缩,都是{1012}拉伸孪晶(TTW)主导变形,并出现大量反常孪生行为(施密特因子(m)<0)。反常孪生行为在拉伸下随着Y含量增加更加明显,表明更高含量的Mg−Y合金中孪生变体选择更加随机。然而,在压缩下依赖于Y含量的反常孪生行为是相反的。研究还发现,反常拉伸孪晶的比例在拉伸和压缩下分别与相应母晶粒中基面和柱面滑移的最大施密特因子(m_(max))密切相关,表明当前Mg−Y合金中孪生和滑移或许有着密切联系。
The influence of Y content on the grain-scale twinning behavior in extruded Mg−xY(x=0.5,1,5,wt.%)sheets under uniaxial tension and compression along the extruded direction was statistically investigated.An automatic twin variant analysis was employed,based on large data sets obtained by electron backscatter diffraction(EBSD),including 2691 grains with 977 twins.The{1012}tension twinning(TTW)dominance and prevailing anomalous twinning behavior(Schmid factor(m)<0)under both tension and compression were found.The anomalous twinning behavior was more pronounced as Y content increased under tensile loading,indicating a promoted stochasticity of twin variant selection for more concentrated Mg−Y alloys.However,the trend for the Y-content dependent anomalous twinning behavior was opposite in compression.The fractions of the anomalous TTWs were found to be well correlated with the maximum Schmid factor(m_(max))values of basal slip and prismatic slip in the corresponding parent grains for compression and tension,respectively,indicating that twinning and dislocation slip might be closely related in the present Mg−Y alloys.
作者
柴艳琴
尹冬弟
华珅
黄广号
周浩
郑江
王渠东
Yan-qin CHAI;Dong-di YIN;Shen HUA;Guang-hao HUANG;Hao ZHOU;Jiang ZHENG;Qu-dong WANG(Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;Nano and Heterogeneous Materials Center,School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;Shenyang National Laboratory for Materials Science,International Joint Laboratory for Light Alloys(Ministry of Education),College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China;National Engineering Research Center of Light Alloys Net Forming,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)
基金
the National Natural Science Foundation of China(Nos.51401172 and 51601003)
Fundamental Research Funds for the Central Universities,China(No.2682020ZT114)
open funding of International Joint Laboratory for Light Alloys(MOE),Chongqing University,China。
