Abstract:The Al-Zn-Mg-Cu alloy strip can be successfully fabricated by twin roll casting. In order to determine the effect of thickness reduction and heat treatment temperature on the recrystallization behavior, the strips were rolled and subsequently heat treated under various conditions. As a result, a fine grained microstructure (average grain size ~13 μm, average grain aspect ratio ~1.7) and high mechanical properties (UTS ≥360 MPa, δ ≥20%) were obtained by cold rolling with thickness reduction of 60% and heat treatment at 500 °C for 1 h. Also, the effect of the microstructure on mechanical properties of the Al-Zn-Mg-Cu alloy strip was discussed. Consequently, the low cost and high strength Al-Zn-Mg-Cu alloy sheet can be fabricated by twin roll casting by proper thermo-mechanical processes.

Key words: Al-Zn-Mg-Cu; twin roll casting; cold rolling; recrystallization