Microstructure, growth kinetics and mechanical properties of interface layer for roll bonded aluminum-steel clad sheet annealed under argon gas protection

In this paper, an annealing treatment was performed to eliminate the work hardening effect of cold roll-bond clad sheets, and the effect of annealing temperature and time on the microstructure evolution at steel/aluminum interface and mechanical properties of aluminum-steel clad sheet were investigated. Results showed that the longer the time and the higher the temperature are, the thicker the inter-diffusion zone become. Fe2Al5 phase preferentially formed at the inter-diffusion layer at 600 °C. As the annealing temperature increased, another FeAl3 phase gradually formed. The thickness of intermetallic compound layers over 10 μm would seriously deteriorated the mechanical properties of aluminum-steel clad sheet. Furthermore, the relationship of the thickness of inter-diffusion layer with the annealing time and temperature was established, which played a vital role in predicting the working time of aluminum-steel clad sheet.