Intermetallic Compounds (IMCs) Formation in Al/Mg Dissimilar Alloy Solid State Joining: Experimental Study and Phase Field Modeling

作者：Song, Kuijing^*; Liu, Xinquan; Ji, Yukai; Wei, Yong; Luo, Junrui; Liu, Fei; Liu, Dashuang; Zhong, Zhihong

来源：Metals and Materials International, 2023, 29(4): 1165-1180.

DOI：10.1007/s12540-022-01292-8

• Intermetallic compound
• Solid state joining
• Phase-field model
• Interdiffusion
• Growth kinetics

Aluminum/magnesium (Al/Mg) alloys have good metallurgical compatibility as well as similar melting and recrystallization temperatures. Therefore, the formation of deleterious IMCs is considered as a major problem in dissimilar Al/Mg alloys joining. In this paper, the metallurgical reaction behavior and atomic diffusion in Al/Mg solid state joining interface are studied. Based on the thermodynamic, kinetic and crystallographic characteristics of ordered phase transformation and atomic diffusion database, a phase field calculation framework of the polycrystalline beta-Al3Mg2 and gamma-Al12Mg17 evolution is developed. Diffusivity, D and interface mobility, M, which significant kinetic parameters are defined as alloy compositions and joining conditions dependent. By a series of simulation, it is proved the simulated interdiffusion microstructural characteristics and element distribution across the joining interface are in coincidence with the corresponding experimental data. The thermally activated IMC evolution in diffusion bonding is in thermodynamic equilibrium, while accelerated IMC evolution in friction stir welding results from thermomechanically activated D and M. The present study contributes to the understanding of interfacial microstructures evolution in solid state joining of dissimilar alloys.