Mg-Y-Nd-Zn合金中LPSO的存在对孪晶形成的影响  

Effect of existing LPSO structure on twin formation in Mg-Y-Nd-Zn alloy

作　　者：汪涛[1] 孙威[1] 王子荣[1] 杨旭[1] 封钰明 刘林林[1] WANG Tao SUN Wei WANG Zi- rong YANG Xu FENG Yu-ming LIU Lin-lin(Institute of Microstructure and Property of Advanced Materials,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学固体微结构与性能研究所,北京100124

出　　处：《电子显微学报》2016年第5期393-398,共6页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.50571002;No.51171004)

摘　　要：利用背散射电子衍射(EBSD)和透射电子显微镜(TEM)技术研究了含LPSO结构的Mg-1.1Y-0.4Nd-0.8Zn(at.%)合金中的孪晶形成特征。结果发现14H型LPSO结构的存在对压缩变形所生成孪晶类型影响不大,但会使孪晶板条尺寸减小且与板条边界交截产生台阶。受14H型LPSO结构存在的影响,(1012)孪晶表现出两种生长形态:在LPSO片层较窄且分布稀疏区域,孪晶可直接切过并使LPSO片层发生3.7°弯折;而在LPSO片层较厚其密度较高区域,孪晶无法穿越LPSO片层,但其可通过在随后片层的另一端重新形核生长方式继续进行传播。Twin formation in the deformed Mg-1. 1Y-0. 4Nd-0. 8Zn（ at. %） alloy has been studied by a combination of EBSD and TEM examinations. The results show that the existing 14 H type LPSO structure has less influence on the twinning mode when the alloy subjected to compressive deformation,but can result in a decrease of twin size and in occurrence of intersecting steps in the twinning surfaces as well. Concerning the effect of pre-existing LPSO structure on the（ 1012） twinning process,two kinds of growth features have been observed. When the（ 1012） twin growth proceeds in a region distributed with thin and widely-spaced LPSO slabs,the twinning can cross the LPSO layers by bending them to a angle of 3. 7°. When encountering thick and closely-spaced LPSO slabs,the twinning can not cross them,but instead can initiate again in the Mg matrix beyond these LPSO slabs through a process including nucleation and growth. This process can occur in sequence such that deformation twinning appears to propagate forward.

关 键 词：镁合金 长周期 孪晶 室温变形 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG115.215.3[金属学及工艺—金属材料]