Effect of Ta on the Microstructure of High Performance Ni-based Powder Metallurgy Superalloy
Effect of Ta on the microstructures of nickel-based powder metallurgy superalloy with different Ta content was investigated experimentally and by thermodynamic calculation.It was shown that most Ta element exists in γ phase.The γ matrix also contains some Ta,while little of Ta exists in MC carbides.Ta substitutes part of Ti,Nb to make the(Ti,Nb)C transform to(Ti,Ta,Nb)C.In addition to the MC carbides,a small amount of M23C6 carbides was also observed on the grain boundaries which was ribbon-like.It was also observed that Ta has little effect on the primary γ phase,but has a great influence on the secondary γ phase.Ta promoted the tendency of splitting of the secondary γ phase,causing it turn to a more stable state.As the Ta content increased,the lattice constants of γ and γ all increased,and the degree of misfit between γ/γ changed which led to the change of morphology.Besides,Ta content has a certain influence on the formation of tertiary γ phase.
Superalloy Powder metallurgy Microstructure Carbides γ
Wang Zhicheng Wang Hao Hu Benfu Huang Hailiang Zhang Hongfei Shao Yinlong
School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China
国际会议
北京
英文
1125-1133
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）