Ni80A高温合金等温压缩过程中低能孪晶界密度在时空域的分布及演化  

Distribution and evolution of low-energy twin boundary density in time−space domain during isothermal compression for Ni80A superalloy

作　　者：赵江 权国政[1,2] 张钰清 熊威 Jiang ZHAO;Guo-zheng QUAN;Yu-qing ZHANG;Wei XIONG(Chongqing Key Laboratory of Advanced Mold Intelligent Manufacturing,College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China;State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;Collaborative Innovation Center of Advanced Nuclear Energy Technology,Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education,Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]重庆大学材料科学与工程学院重庆市先进模具智能制造重点实验室,重庆400044 [2]华中科技大学材料成形与模具技术国家重点实验室,武汉430074 [3]清华大学核能与新能源技术研究所先进反应堆工程与安全教育部重点实验室先进核能技术协同创新中心,北京100084

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第11期3387-3405,共19页中国有色金属学报（英文版）

基　　金：supports from the National Natural Science Foundation of China(No.52175287);the Open Fund of State Key Laboratory of Materials Processing and Die&Mould Technology,China(No.P2021-001).

摘　　要：调控合金热变形中低能晶界(Σ3^(n)孪晶界)密度是提高合金晶界相关性能的重要手段。为揭示在电热成形过程中孪晶界密度的分布、演化及其与晶粒尺寸和储能相关的内在机制,建立电-热-力多场、宏微观多尺度耦合有限元模型。一系列Ni80A高温合金在等温压缩过程中的模拟结果表明:在加热和保温阶段,孪晶界密度基本不变;在压缩阶段,孪晶界密度先快速增加而后倾向于降低。等温压缩样中孪晶界密度的分布在高温和中等应变速率下更加均匀。与细晶粒尺寸、高储能及高动态再结晶程度相对应的热变形参数区间有助于提高孪晶界密度。Adjusting the density of low-energy boundary,i.e.,Σ3^(n) twin boundary,in a thermal-plastic deformation process is a significant approach to enhance grain boundary-related properties for an alloy.In order to uncover the distribution and evolution of twin boundary density in a current-heating forming process,and their inner mechanisms dependent on grain size and stored-energy,an electrical-thermal-mechanical multi-field coupling and macro-micro multi-scale coupling finite element model was established.Simulation results of isothermal compression processes for Ni80A superalloy show that twin-boundary density keeps constant in the heating and holding stages,while it increases quickly and then intends to decrease in the compressing stage.Its distribution gets more homogeneous under high temperature and medium strain rate.The processing parameter domains corresponding to finer grain size and higher stored-energy,as well as higher dynamic recrystallization degree,contribute to promoting the twin boundary density.

关 键 词：Σ3n孪晶界 多尺度耦合模拟 电热成形 镍基高温合金 

分 类 号：TG132.3[一般工业技术—材料科学与工程]