Effect of heating-rate on failure temperature of pre-loaded magnesium alloy

The response and failure of magnesium alloy AZ31 specimens subjected to different pre-loaded-stress levels and heating rates were investigated with a Gleeble-1500 thermo-mechanical material testing system. It is found that the increases of either pre-loaded stresses or heating-rates decrease the failure temperatures of the specimens. The metallographs of the tested specimens were also observed. It is shown that the high heating-rate may cause stronger local thermal inconsistency, which remarkably increases the microdefects and reduces the macroscopic mechanical properties of the material.