Growth kinetics and thickness prediction of interfacial intermetallic compounds between solid steel and molten aluminum based on thermophysical simulation in a few seconds

The growth kinetics of intermetallic compounds (IMCs) generated by initial interfacial reaction (interaction time < 10 s) between solid steel and molten aluminum was investigated using a thermophysical simulation method. According to the morphology evolution of the eta (Fe(2)A(15)) and theta (Fe4Al13) phase layers in the isothermal experiments in seconds, it is confirmed that the reaction diffusion controls the eta phase growth and the 0 phase precipitates from the liquid phase during cooling. The growth kinetics models of the eta phase maximum and average thickness are proposed as well. The results showed that the maximum growth was governed by the interfacial reaction, whereas the average thickness was governed by a diffusion and interfacial reaction process. Considering the application of the kinetics model in welding-brazing of Fe/Al dissimilar metals, a mathematical model to predict the average thickness of 11 phase was established using the finite difference method in thermal cycles as well. The predicted results are consistent with the experimental results, indicating that the model is of good accuracy.