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孪生是密排六方结构(HCP)金属中协调塑性变形的重要方式，理解孪生行为对设计高强韧Mg合金具有重要意义.本研究中以典型的Mg-xGd(x=4%, 8%, 12%, 16%, 20%,质量分数)二元合金为模型合金，使用电子背散射衍射仪(EBSD),系统研究了其室温压缩过程中的孪生变形行为.研究结果表明：当Gd质量分数小于12%时，合金的室温压缩以■孪晶为主；继续添加Gd,孪生类型逐渐由■孪晶变为■孪晶，当Gd添加量(质量分数，下同)为16%时，■孪晶开始出现，且随着Gd添加量的增加，■孪晶也越来越多.稀土元素Gd的含量是室温压缩条件下形成■孪晶的决定性因素，只有当Gd的添加量达到一定值时，才会形成■孪晶.研究结果还表明，Gd的添加量越多，压缩应变量越大，压缩速率越大，■孪晶越容易形成.
Abstract：Twinning is a critical deformation mechanism in hexagonal close-packed(HCP) metals, playing a pivotal role in plasticity. Understanding the factors that govern twinning behavior is essential for the design of high-strength, tough Mg alloys. In this study, typical Mg-xGd(x=4%, 8%, 12%, 16%, 20%,mass fraction) binary alloys have been used as model alloys. Electron backscatter diffraction(EBSD) has been used to systematically investigate the twinning deformation behavior during room temperature compression. The findings demonstrate that when the mass fraction of Gd is less than 12%, the dominant twinning mode is ■ twinning. As the Gd content increases, a gradual transition to ■ twinning occurs. Notably, upon reaching a Gd content(mass fraction, the same below) of ■ twinning first appears and becomes more prevalent with increasing Gd concentrations. The content of rare earth element Gd is the decisive factor in the formation of ■ twins under room-temperature conditions. ■ twins could only form when the amount of Gd added reaches a certain value. The research results also show that the higher the amount of Gd added, the greater the compression strain, the higher the compression rate, and the easier it is for ■ twins to form.
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基本信息:
DOI：10.14186/j.cnki.1671-6620.2026.01.008
中图分类号:TG146.22
引用信息:
[1]张欣,李姗姗,任玉平,等.Mg合金中■孪晶的形成条件[J].材料与冶金学报,2026,25(01):60-69.DOI:10.14186/j.cnki.1671-6620.2026.01.008.
基金信息:
国家自然科学基金青年基金项目(52101129); 中央高校基本科研业务费项目[DUT23RC(3)062]
2026-01-04
2026-01-04
2026-01-04