Study of the Growth Behavior of Intermetallic Compounds at the Liquid-Solid Interface of Bal88si/Cu

Since the formation of intermetallic compounds at the copper-side interface for the duration of the copper/aluminum brazing process leads to a reduction in the mechanical properties of the brazing joint, and the diffusion and reaction process between the molten filler metal and the base material is difficult to control, the purpose of this thesis is to investigate the diffusion between the filler metal and the base material through the wetting test of the filler metal on the copper base material, controlling the heating temperature and holding time, analyzing the microstructure of the interfacial compounds using SEM and EDS, studying the diffusion behavior of the filler metal and the base material, and the Effective Heat of Formation (EHF) model was used to predict the formation of the first phase of the interfacial compound and to analyze the growth kinetics of the interfacial compound. The experimental results show that the diffusion layer of the BAl88Si/Cu interface is composed of Cu 9 Al 4 , Cu 3 Al 2 , Cu 4 Al 3 and CuAl under the heating temperature of 600 °C and the holding time of 10 min, and the thickness of the diffusion layer increases significantly with the holding time. According to the EHF model, the first intermetallic compound formed at the interface is predicted to be CuAl 2 which is consumed during the reaction and diffusion process. The activation energies of Cu 9 Al 4 and the total diffusion layer are 125.33 kJ/mol and 184.93 kJ/mol, respectively