不同次要相体积分数的亚共晶层-棒转变的多相场模拟  

Multi-phase field simulation of lamellar-rod hypoeutectic transition with different volume fractions of the minor phase

作　　者：杨玉娟[1,2] 严彪[1,2] 

机构地区：[1]同济大学材料科学与工程学院,上海200092 [2]同济大学上海市金属功能材料开发应用重点实验室,上海200092

出　　处：《北京科技大学学报》2010年第8期1029-1034,共6页Journal of University of Science and Technology Beijing

基　　金：中国博士后基金资助项目(No.20090460654);上海市科委资助项目(No.08DZ2201300;No.0752nm004)

摘　　要：利用KKSO多相场模型,对亚共晶模型合金的层-棒转变过程进行模拟.结果表明,共晶形态的层-棒转变不是突变而是在一定成分范围内渐变的.在各向同性界面能条件下,当次要相体积分数远小于1/π时,共晶形态将发生层-棒转变,该相以棒状形式存在;当次要相体积分数在1/π附近时,层片共晶不完全向棒状共晶转变,且随着次要相体积分数的增大,转变时刻推迟;当次要相的体积分数远大于1/π时,层片状共晶不再向棒状共晶转变.共晶形态的层-棒转变趋势与初始层片间距有关,模拟结果与实验结果定性一致.Critical simulations of model hypoeutectic alloys were carried out with the KKSO multi-phase field model to study the lamellar-rod eutectic transition. The result shows that the lamellar-rod eutectic transition does not appear abrupt but occurs over a range of compositions. Under the condition of isotropic interface energy, when the volume fraction of the minor phase is far lower than 1/π, the lamellar-rod transition occurs, and a rod microstructure forms. When the volume fraction of the minor phase is near to 1/π, the la- mellar-rod transition does not occur completely, and it occurs later with the volume fraction of the minor phase increasing. When the volume fraction of the minor phase is far larger than I/π, it does not occur any longer. The simulations also show that the transition is related with initial lamellar spacing, which is in accordance with the experiment results qualitatively.

关 键 词：合金 亚共晶 共晶 形态 模拟 

分 类 号：TG111.5[金属学及工艺—物理冶金]