An atomic insight into effect of grain boundary on diffusion behavior of Cu/Al dissimilar materials undergoing ultrasonic welding  

作　　者：Jing-wei Yang Chu-hao Xie Jie Zhang Zong-ye Ding Jian Qiao 

机构地区：[1]School of Mechatronic Engineering and Automation,Foshan University,Foshan,528225,Guangdong,China [2]School of Mechanical Engineering,University of Science and Technology Beijing,Beijing,100083,China [3]Shanghai Key Laboratory of Materials Laser Processing and Modification,School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai,200240,China [4]State Key Laboratory of Advanced Brazing Filler Metals&Technology,Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.,Zhengzhou,450001,Henan,China

出　　处：《Journal of Iron and Steel Research International》2024年第10期2555-2567,共13页钢铁研究学报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China under Grant(Nos.51805084 and No.51904187);Guangdong Basic and Applied Basic Research Foundation(Nos.2023B1515120086 and 2023A1515140124);the Fundamental Research Funds for the Central Universities(No.00007706).

摘　　要：The diffusion processes in bicrystalline Cu/Al joints,characterized by typical high-angle grain boundaries(GBs),were investigated using molecular dynamics simulations.It was found that GBs facilitated the diffusion of both Cu and Al atoms,predominantly enhancing the migration of Cu atoms into Al matrix.According to mean squared displacement results,the movement of Al atoms within Al matrix was more vigorous than that of Cu atoms.The mechanisms of atomic rearrangement,dislocation movement,stacking fault formation,and dynamic recrystallization were analyzed.During the compression and initial welding stages,the mismatch in lattice constants and the twisting of grains initiated a squeeze-induced rearrangement of Al atoms at the interface,leading to the formation of dislocations and vacancies.During the advanced stages of welding,the plastic deformation primarily occurred within Al matrix,marked by the emergence of dislocations,stacking faults,and GB sliding.Particularly,the shearing effect during the ultrasonic welding process,combined with GB sliding,collectively induced grain recrystallization at the interface.Furthermore,the diffusion between Cu/Al joints could be enhanced by increasing the vibration frequency,due to a significant rise in the number of amorphous regions.

关 键 词：Grain boundary Molecular dynamics Diffusion behavior Ultrasonic welding Dissimilar material 

分 类 号：TG113[金属学及工艺—物理冶金]