Mg-Al合金Mg_(17)Al_(12)连续析出相形貌的相场模拟  

PHASE FIELD SIMULATION ON MORPHOLOGY OF CONTINUOUS PRECIPITATE Mg_(17)Al_(12)IN Mg-Al ALLOY

作　　者：韩国民[1] 韩志强[1] AlanA.Luo AnilK.Sachdev 柳百成[1,3] 

机构地区：[1]清华大学机械工程系先进成形制造教育部重点实验室 [2]Chemical Sciences and Materials Systems Laboratory,General Motors Global Research and Development Center,Warren,MI48090-9055,USA [3]清华大学汽车工程系汽车安全与节能国家重点实验室

出　　处：《金属学报》2013年第3期277-283,共7页Acta Metallurgica Sinica

基　　金：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;清华大学自主科研计划项目2011Z02160资助~~

摘　　要：基于KKS相场模型模拟了Mg-Al合金Mg_(17)Al_(12)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.The morphology evolution of the continuous precipitate Mg17Al12 in aging process was studied using KKS phase field model. In the model, the chemical free energy and chemical potential for the precipitate phase and matrix were obtained by using Thermo-Calc software and database. The effects of interfacial energy anisotropy were taken into account by introducing interface anisotropy function, and the effects of micro elastic strain energy were introduced based on the theory of micro elastic strain energy formulated by Khachaturya. It is demonstrated that the precipitate phase has a lath shape when only the interfacial energy anisotropy was considered regardless of the micro elastic strain energy.The precipitate phase grows into a diamond shape when only the micro elastic strain energy was taken into account regardless of the interracial energy anisotropy. When both the effects of the interracial energy anisotropy and the micro elastic strain energy were considered in the simulation, the precipitate phase has a lath shape with lozenge ends, which is in agreement with experimental observations. The interfacial energy anisotropy affects the overall morphology of the precipitate, and combining the interracial energy anisotropy and the micro elastic strain energy results in the lath shape with lozenge ends.

关 键 词：MG-AL合金 连续析出相 形貌演化 热力学计算 界面能各向异性 微观弹性应变能 相场模型 

分 类 号：TG111.4[金属学及工艺—物理冶金]