Effects of Thermal-Mechanical Cycling on Tension Properties of AZ31 Magnesium Alloy

Effects of thermal-mechanical cycling on tension properties of an extruded AZ31 alloy are studied. The results show that the strength of the examined AZ31 alloy samples varies with thermal cycles, increasing from non-cycle to 50 cycles and then decreasing to 380 cycles. The plastic elongation exhibits out of steps tendency which has maximum at 100 cycles and decreases after that. Microstructure development indicates that dislocation and twinning induced by accumulated internal stress vary with thermal cycling. And the tension fracture surface of the thermal cycled samples shows that fracture of cycled samples transits from cleavages and facets into dimple and second phase crack dominated feature. It is believed that dislocation and twinning evolution during thermal cycling are responsible for the observed tension deformation and fracture behaviors.