Mg-Al合金Mg17Al12连续析出相形貌的相场模拟
收稿日期: 2012-09-10
修回日期: 2012-12-30
网络出版日期: 2013-03-11
基金资助
国家自然科学基金项目51175291, 科技部国际科技合作计划课题2010DFA72760和2011DFA50909及
PHASE FIELD SIMULATION ON MORPHOLOGY OF CONTINUOUS PRECIPITATE Mg17Al12IN Mg-Al ALLOY
Received date: 2012-09-10
Revised date: 2012-12-30
Online published: 2013-03-11
基于KKS相场模型模拟了Mg-Al合金Mg17Al12单个连续析出相的形貌演化. 相场模型中, 各相自由能及化学势由Thermo-Calc热力学计算软件计算. 构造各向异性函数时考虑了界面能各向异性的影响, 基于Khachaturyan微观弹性应变能理论考虑了微观弹性应变能的影响. 结果表明: 仅考虑界面能各向异性不考虑微观弹性应变能, 析出相呈板条状形貌; 仅考虑微观弹性应变能不考虑界面能各向异性, 析出相呈菱形; 综合考虑界面能各向异性和微观弹性应变能, 析出相呈板条状形貌, 端部呈平行四边形, 此形貌特征与实验观察结果吻合; 界面能各向异性决定析出相的板条状形貌特征, 微观弹性应变能导致端部产生平行四边形特征.
韩国民 , 韩志强 , Alan A. Luo , Anil K. Sachdev , 柳百成 . Mg-Al合金Mg17Al12连续析出相形貌的相场模拟[J]. 金属学报, 2013 , 49(3) : 277 -283 . DOI: 10.3724/SP.J.1037.2012.00531
The morphology evolution of the continuous precipitate Mg17Al12 in aging process was studiedusing KKS phase field model. In the model, the chemical free energy and chemical potential for the precipitatephase and matrix were obtained by using Thermo-Calc software and database. The effects of interfacial energyanisotropy were taken into account by introducing interface anisotropy function, and the effects of micro elasticstrain energy were introduced based on the theory of micro elastic strain energy formulated by Khachaturya. It isdemonstrated that the precipitate phase has a lath shape when only the interfacial energy anisotropy wasconsidered regardless of the micro elastic strain energy.The precipitate phase grows into a diamond shape whenonly the micro elastic strain energy was taken into account regardless of the interfacial energy anisotropy. Whenboth the effects of the interfacial energy anisotropy and the micro elastic strain energy were considered in thesimulation, the precipitate phase has a lath shape with lozenge ends,which is in agreement with experimental observations. The interfacial energy anisotropy affectsthe overall morphology of the precipitate, and combiningthe interfacial energy anisotropy and the micro elastic strain energy results in the lath shape with lozenge ends.
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