摘要
本文借助像差校正透射电子显微镜研究了富钴镍基高温合金在高温拉伸变形过程中不同尺度的γ′相对合金变形机制的影响。研究发现,随着γ′相尺寸的增加,基体位错以位错对的方式切割γ′相逐渐转变为以Orowan机制绕过γ′相,并在其周围形成位错环;而不全位错能否切入γ′相主要取决于层错的类型(内禀或外禀),与γ′相的尺寸无关。同时发现,层错之间的交互作用能够促使内禀层错转变为外禀层错并可逐步增加错排片层数量,最终演变为可剪切所有尺寸γ′相的变形孪晶。本文对γ′相尺寸效应的影响以及层错转变为孪晶的过程的研究将有利于对后续合金设计提供理论参考。
The scaling effect ofγ′phase on the tensile deformation of cobalt⁃rich nickel⁃based superalloy at high temperature is investigated through aberration⁃corrected transmission electron microscopy.The results suggest that with the increase ofγ′phase’s size,the activation manner of matrix dislocations prefers to bypassγ′phase following the Orowan mechanism and leaves dislocation loops around theγ′phase rather than cuttingγ′phase.While the potential of partial dislocations penetratingγ′phase is mainly governed by the mode of stacking faults(intrinsic or extrinsic),rather than the size ofγ′phase.It is also found that the interaction between stacking faults can promote the transformation of intrinsic stacking faults into extrinsic stacking faults and gradually increase the number of staggered sheets,thus evolve into deformation twins,which can shear intoγ′phase without size limitation.The investigations on the scaling effect ofγ′phase and the process of stacking faults transforming into twins,may be beneficial to the subsequent alloy design.
作者
齐东卿
赵鹏
崔传勇
叶恒强
杜奎
QI Dong-qing;ZHAO Peng;CUI Chuan-yong;YE Heng-qiang;DU Kui(Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang Liaoning 110016;School of Chemistry and Chemical Engineering,Shandong University,Jinan Shandong 250100;Ji Hua Laboratory,Foshan Guangdong 528200,China)
出处
《电子显微学报》
CAS
CSCD
北大核心
2022年第5期499-506,共8页
Journal of Chinese Electron Microscopy Society
基金
国家自然科学基金资助项目(Nos.52171020,91960202)
山东省自然科学基金资助项目(No.ZR2021QE103)
关键词
富钴镍基高温合金
γ′相
位错
层错
孪晶
cobalt⁃rich nickel⁃based superalloy
γ′phase
dislocation
stacking fault
twin
