VW53镁合金室温压缩过程中的孪生行为研究

Twinning behavior of VW53 magnesium alloy during compression at room temperature

摘要:

本文研究了Mg-5.65Gd-3.15Y-0.48Zr（VW53）镁合金室温压缩过程中的孪生行为及其对组织性能的影响，通过将固溶态VW53镁合金在室温下进行不同应变的压缩实验，然后利用光学金相显微镜（OM）、扫描电子显微镜（SEM）和电子背散射衍射（EBSD）等技术对试样进行微观组织观察和分析，并测试试样的维氏显微硬度。结果表明：VW53镁合金在室温压缩过程中，主要产生{10-12}拉伸孪晶和{11-21}拉伸孪晶，随着应变增加{10-12}孪晶会形核、生长、合并、甚至吞并整个晶粒，而{11-21}孪晶不会发生显著的扩展合并。孪晶界可以阻碍位错移动和分割细化晶粒，随着应变的增加，孪晶界相互交截和分割细化晶粒的程度提高，可以有效提高VW53镁合金力学性能。

Abstract:

In the study, the twinning behavior of VW53 magnesium alloy in solid solution was studied by compression experiments under different strains at room temperature, and the effects of twinning on microstructure and properties were investigated. The microstructure of VW53 magnesium alloy was observed and analyzed by optical metallography (OM), scanning electron microscopy (SEM) and electron backscattering diffraction (EBSD). Vickers microhardness was tested. The results show that {10-12} tensile twins and {11-21} tensile twins are mainly produced during the compression process of VW53 magnesium alloy at room temperature. With the increase of strain {10-12} twins will nucleate, grow, merge, and even annex the entire grain {10-12} twins will nucleate, grow, merge, and even annex the entire grain, while {11-21} twins will not expand and merge significantly. With the increase of strain, the degree of cross-cutting of twin boundary and segmentation of refined grain increase, which can effectively improve the mechanical properties of VW53 magnesium alloy.