关键词: 半固态铸造, 叠轧, 深变形, 超细晶, 再结晶, 维氏硬度

Abstract: The ultra-fine grain alloy A2017 was prepared the way the molten alloy A2017 was poured onto tilting corrugated board and then became two semisolid cast slabs for accumulative roll-bonding process to make them composite under the condition the equivalent strain was 4.0, of which the mean grain size was 0.5 p. During the accumulative roll-bonding process the Vichers hardness of workpieces increases then decreases and increases slowly once again along with the increasing number of passes. A2017's microstructure was transformed into stable state from metastable at a certain annealing temperature, i.e., the grain growth is slow at 200°C for 1 hour, while the grains grow obviously if the annealing temperature is higher than 200°C. The microstructure reveals static recovery/recrystallization process with increasing annealing temperature, and the effect of work hardening disappears gradually with Vichers hardness decreased.