Deformation mechanism of AZ31 magnesium alloy at room temperature studied by macro and micro texture measurements
Deformation mechanism of AZ31 magnesium alloy at room temperature studied by macro and micro texture measurements
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宏微观织构测量研究AZ31镁合金室温变形机制
DOI：
10.2464/jilm.66.628
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
T. Ishigaki
中科院分区：
文献类型：
--
作者：
Y. Onuki;A. Hoshikawa;S. Sato;T. Ishigaki
利用光时中子衍射和电子背散射衍射技术，研究了AZ 31镁合金挤压棒材在单向拉伸变形过程中织构的变化。中子衍射织构测量揭示了变形过程中拉伸轴在整个标度体积中分布的转变。拉伸轴的浓度最初在213 <$0 ° C处观察到。随着应变的增加，主峰出现在0.91 <$100 μ m处，初始峰减弱。在变形过程中，合金的总密度降低. EBSD显示{10 1 <$1}压缩孪生和随后的双孪生激活。孪晶区的取向远离α 0 β取向群。随着应变的增加，孪晶的数量逐渐增加。另一方面，基体的变形是通过滑移变形实现的，导致在109 1 <$10 0 °处形成峰。基于以上结果，可以得出结论，镁合金塑性差的原因可能不是缺乏α-Al_2O_3 + α-Al_2O_3滑移，而是孪晶和孪晶内部的变形集中。
The authors measured texture change during uniaxial tensile deformation of extruded bar of AZ31 magnesium alloy by time-of-flight neutron diffraction and EBSD (electron backscatter diffraction). Texture measurement by neutron diffraction revealed the transition of tensile axis distribution in overall gauge volume during the deformation. The concentration of the tensile axis initially observed at 〈 213 ¯ 0 〉 . With increasing strain, the dominant peak appeared at 〈 9 1 ¯ 10 0 〉 and the initial peak weakened. It was also found that the total density of 〈 hki 0 〉 decreased during the deformation. EBSD showed activations of {10 1 ¯ 1} compression twinning and following double twinning. The twinned region were oriented away from the 〈 hki 0 〉 orientation group. The amount of twinning gradually increased with increasing strain. On the other hand, the deformation of the matrix was achieved by slip deformation, resulting in the formation of the peak at 〈 9 1 ¯ 10 0 〉 . Based on the above results, it was concluded that the reason for poor ductility of magnesium alloys may not be a lack of 〈 c+a 〉 slip but twinning and deformation concentration inside of the twins.