镍基高温合金的连续动态再结晶形核机制和退火孪晶演变与晶粒生长的关系  

Continuous dynamic recrystallization nucleation mechanism and annealing twin evolution with respect to grain growth in a nickel-based superalloy

作　　者：汪彦江 贾智 高泽玺 刘德学 WANG Yan-jiang;JIA Zhi;GAO Ze-xi;LIU De-xue(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals(Lanzhou University of Technology),Lanzhou 730050,China;School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals(Lanzhou University of Technology),Lanzhou 730050,China [2]School of Materials Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China [3]School of Materials Science and Engineering,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2023年第1期49-60,共12页中南大学学报（英文版）

基　　金：Project(18JR3RA134) supported by the Science Foundation for Distinguished Young Scholars of Gansu Province,China;Project(CGZH001) supported by the Lanzhou University of Technology Support Plan for Excellent Young Scholars,China;Project(51665032) supported by the National Natural Science Foundation of China;Project(20YF8WA064) supported by the Key R&D Program of Gansu Province-International Cooperation Project,China。

摘　　要：采用电子背散射衍射(EBSD)和透射电子显微镜(TEM)技术对镍基高温合金热压缩变形行为进行了表征。所研究的高温合金在热压缩变形后的主要组织特征是亚晶粒、动态再结晶(DRX)核、DRX晶粒生长和退火孪晶的发展。考虑到变形晶粒之间的近似取向和动态再结晶结果,在低温和高应变率下,除了孪晶辅助再结晶形核外,以亚晶粒结合和旋转为特征的连续动态再结晶(CDRX)形核机制也起着主要作用。MC和γ′析出相在低温(900和1000℃)时促进了DRX的形核,但阻碍了再结晶的生长。高变形温度下的晶粒生长依赖于大角度晶界迁移引起的晶粒相互吞并,这消耗了部分退火孪晶,只有少数退火孪晶在取向偏转后保持稳定。The hot compression deformation behavior of a nickel-based superalloy was characterized by electron backscattered diffraction(EBSD) and transmission electron microscopy(TEM) techniques. The main microstructure characteristics of the studied superalloy after hot compression deformation featured the development of subgrains,dynamic recrystallization(DRX) nuclei, DRX grain growth, and annealing twins. Considering the approximate orientation between deformed grains and the dynamic recrystallization results, we concluded that the continuous dynamic recrystallization(CDRX) nucleation mechanism characterized by subgrain bonding and rotation played a major role at low temperatures and high strain rate in addition to twinning-assisted recrystallization nucleation. The presence of MC and γ′ phase precipitated phases at low temperatures(900 and 1000 ℃) facilitated the nucleation of DRX but hindered the growth of recrystallization. Grain growth at high deformation temperatures depended on the mutual annexation of grains induced by high-angle grain boundary migration, which consumed part of the annealing twins, and only a few annealing twins remained stable after orientation deflection.

关 键 词：镍基高温合金 高应变速率 连续动态再结晶 退火孪晶 析出相 

分 类 号：TG132.3[一般工业技术—材料科学与工程]