Effect of heat treatment on adiabatic shear susceptibility in ZK60 magnesium alloy

Adiabatic shear susceptibility was investigated in the ZK60 magnesium alloy by means of the radial collapse of a thick-walled cylinder. The adiabatic shear susceptibility of ZK60 magnesium alloy samples with different heat treated conditions were evaluated in light of their self-organization characteristics of adiabatic shear bands, such as shear- band spacing, shear- band average length, shear- band average propagated velocity. It is shown that the shear- band spacing in the (as-quenched) sample was 5.2 mm with the effective strain of 0.72 and 4.72 mm with the effective strain of 0.95, one order of magnitude more than that of the peak-aged sample, with shear- band spacing of 0.49 mm (εef=0.72) and 0.38 mm (εef=0.95), respectively. Calculations indicated that the average velocity of shear band propagates nearly 2.5 times faster in the peak-aged sample (271 m/s) than in that of the (as-quenched )sample (105 m/s). Experimental results show that the peak-aged sample has higher adiabatic shear susceptibility, due to precipitates and the higher strength of the peak-aged samples.