Influence of Ta/Al ratio on the microstructure and creep property of a Ru-containing Ni-based single-crystal superalloy  

作　　者：Wei Song Xinguang Wang Jinguo Li Jie Meng Yanhong Yang Jinlai Liu Jide Liu Yizhou Zhou Xiaofeng Sun 

机构地区：[1]Shi-changxu Innovation Center for Advanced Materials,Superalloys Division,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China [2]School of Materials Science and Engineering,University of Science and Technology of China,Shenyang 110016,China

出　　处：《Journal of Materials Science & Technology》2021年第30期16-23,共8页材料科学技术（英文版）

基　　金：financially supported by the National Science and Technology Major Project under(No.2017-Ⅵ-0002-0072);the National Key R&D Program of China(No.2017YFA0700704);the National Natural Science Foundation of China(Nos.51671188,51601192 and 51701210);the Youth Innovation Promotion Association,Chinese Academy of Sciences and State Key Lab of Advanced Metals and Materials Open Fund(No.2018-Z07)。

摘　　要：Two alloys with different Ta and Al contents were applied to study the influence of Ta/Al ratio on the microstructural evolution and creep deformation under high temperature.The increase of Ta/Al ratio made theγ/γ'lattice misfit more negative and enhanced the volume fraction ofγ'phase,which produced cubic and smallγ'phase in the initial microstructures.These initial tinyγ'phases impeded the dislocations movement and delayed the course of complete raftedγ'phase during the origination of creep deformation,which prolonged the time of the primary creep stage.Moreover,the increase of Ta/Al ratio and addition of Ru produced the denser and stable dislocation networks,the high APB energy and better solution strengthening,which hindered the climbing and sliding of dislocations,and restrained the formation of superdislocations in theγ'precipitate.The second creep stage was extended,and the minimum creep rate was reduced.Hence,the increase of whole creep life of the alloy containing high Ta/Al ratio was attributed to the prolongation of the primary and second creep stages,and the low minimum creep rate.The appearance of the topological inversion phenomenon during the tertiary creep stage was the primary cause for the sudden increase of the creep strain rate of the alloy containing low Ta/Al ratio.However,the high creep strain rate of the alloy containing high Ta/Al ratio during the tertiary creep stage was related to the occurrence and extending of the cracks near the voids.Both alloys would lose efficacy within 20 h-30 h.

关 键 词：Ni-based superalloys Ta/Al ratio High temperature creep Interfacial dislocation networks γ'rafting 

分 类 号：TG132.3[一般工业技术—材料科学与工程]