镍基高温合金雀斑缺陷数值模拟  

Numerical Simulation of Freckle Defects in Nickel-based Superalloys

作　　者：刘东戎[1] 任莹 郭二军[1] LIU Dong-rong;REN Ying;GUO Er-jun(School of Material Science and Engineering, Harbin University of Science and Technology, Harbin, 150080, China)

机构地区：[1]哈尔滨理工大学材料科学工程学院,哈尔滨150080

出　　处：《哈尔滨理工大学学报》2020年第2期118-124,共7页Journal of Harbin University of Science and Technology

基　　金：黑龙江省自然科学基金(2017045);国家自然科学基金(51101045)。

摘　　要：为深入理解镍基高温合金定向凝固过程中雀斑缺陷的演化特点,基于SIMPLE(semi-implicit method for pressure linked equations)算法,采用流体力学三大方程计算模拟研究CMSX-2合金定向凝固过程中雀斑形成。借助文献中模拟结果验证模型,考察了几何形状和合金成分对铸件凝固过程中的流场、固相分数场及溶质偏析分布的影响。模拟结果表明:带有收缩截面的铸件形状易促进雀斑产生。铸件合金成分中Al元素会促进雀斑形成,而Ta元素则对抑制雀斑形成起到了较好作用。In order to deeply understand the formation characteristics of freckle defects in the process of directional solidification of nickel-based superalloy,three major equations of fluid mechanics were used to simulate the formation of freckles during the directional solidification of CMSX-2 superalloy based on the SIMPLE(Semi-Implicit Method for Pressure Linked Equations)algorithm.The simulations in the reference were used to validate the model.The effects of geometric shape and alloy composition on the flow field,solid fraction field and solute segregation distribution during solidification of the casting were investigated.The simulations show that freckles are easily formed in the casting with shrinkage section.The Al element in the alloy composition promotes the formation of freckles,while the Ta element plays a very good role in suppressing the formation of freckles.

关 键 词：镍基高温合金 雀斑 数值模拟 

分 类 号：TG244[金属学及工艺—铸造]