Al-Mg合金孪晶变形的第一性原理研究（英文）

发布时间：2018-04-30 09:56

本文选题：广义层错能 + 本征层错能　；参考：《Transactions of Nonferrous Metals Society of China》2017年06期

【摘要】：镁元素可以降低铝的本征层错能,因而Al-Mg合金被认为具备孪晶变形的潜力。然而在多种大变形Al-Mg合金中很难发现变形孪晶。为了探究Al-Mg合金的孪晶变形潜能,采用第一性原理计算研究镁和空位对铝广义层错能的影响。研究发现Mg和空位均具有层错Suzuki偏析特性,并且会降低Al的本征层错能。但是随着镁含量的提高,铝的本征层错能不会持续降低,孪晶特性参数τa也不会持续升高。基于Al-Mg合金的孪晶特性参数τa,我们预测即使在高固溶镁含量下,Al-Mg合金依然很难发生孪晶变形。镁和空位所引起的本征层错能的降低在一定程度上能够提高大变形Al-Mg合金的加工硬化速率并且促进变形带的形成。
[Abstract]:Magnesium can reduce the intrinsic stacking fault energy of aluminum, so Al-Mg alloy is considered to have the potential of twin deformation. However, it is difficult to find deformation twins in many kinds of large deformation Al-Mg alloys. In order to explore the twinning deformation potential of Al-Mg alloy, the effect of magnesium and vacancy on the generalized stacking fault energy of aluminum was studied by first principle calculation. It is found that both mg and vacancy have the characteristics of stacking fault Suzuki segregation and decrease the intrinsic stacking fault energy of Al. However, with the increase of magnesium content, the intrinsic stacking fault energy of aluminum will not decrease and the twin characteristic parameter 蟿 a will not continue to increase. Based on the twin characteristic parameter 蟿 _ a of Al-Mg alloy, we predict that twinning deformation of Al-Mg alloy is still very difficult even when the content of solid magnesium is high. The reduction of intrinsic stacking fault energy caused by magnesium and vacancy can improve the work hardening rate of large deformation Al-Mg alloy and promote the formation of deformation zone to a certain extent.
【作者单位】： Department
【基金】：Project(222173) supported by the FRINATEK project ‘BENTMAT’ from the Research Council of Norway
【分类号】：TG146.21

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