Finite element analysis of γ'-phase raft mechanism in Ni-based single crystal superalloy  

作　　者：吴文平 郭雅芳 汪越胜 

机构地区：[1]Institute of Engineering Mechanics,Beijing Jiaotong University,Beijing 100044,China

出　　处：《中国有色金属学会会刊：英文版》2006年第A03期1990-1994,共5页Transactions of Nonferrous Metals Society of China

基　　金：Projects(10572019, 10672016)supported by the National Natural Science Foundation of China;project(2005SM0035) supported by the Science Foundation of Beijing Jiaotong University, China

摘　　要：The finite element method was applied to study the mechanics of rafting ofγ' precipitates in a single crystal Ni-based superalloy with the [001] orientation. The results show that the creep and rafting are closely related with the stress and strain energy density distributions in the matrix channels. The application of an external stress leads to differential levels of von Mises stress and strain energy density, and the largest value of the stress appears at the corners of the matrix near the interface. Creep dislocations penetrate preferentially into the most highly stressed matrix channels where theγ'-phase rafting is also enlarged. Meanwhile, the von Mises stress ofγmatrix andγ' precipitate increases with the increase of temperature, thus the rafting becomes easier at a higher temperature. Moreover, according to the analysis of slip systems for the Ni-based superalloy, the critical external load for bowing a dislocation through a matrix channel at 950℃is about 180 MPa, which is consistent with the related experimental results.The finite element method was applied to study the mechanics of rafting of γ＇ precipitates in a single crystal Ni-based superalloy with the [001] orientation. The results show that the creep and rafting are closely related with the stress and strain energy density distributions in the matrix channels. The application of an external stress leads to differential levels of von Mises stress and strain energy density, and the largest value of the stress appears at the comers of the matrix near the interface. Creep dislocations penetrate preferentially into the most highly stressed matrix channels where the ）,＇-phase rafting is also enlarged. Meanwhile, the yon Mises stress of ）, matrix and ）,＇ precipitate increases with the increase of temperature, thus the rafting becomes easier at a higher temperature. Moreover, according to the analysis of slip systems for the Ni-based superalloy, the critical external load for bowing a dislocation through a matrix channel at 950 ℃ is about 180 MPa, which is consistent with the related experimental results.

关 键 词：镍 高温合金 有限元分析 机械性能 晶体 

分 类 号：TG132[一般工业技术—材料科学与工程]