Precipitation and responding damping behavior of heat-treated AZ31 magnesium alloy

Microstructure observation and dynamic mechanical analysis were carried out to investigate the precipitation and responding damping behaviors of AZ31 magnesium alloy. All the strain amplitude-dependent damping curves of the aged alloys are located between the curves of solutionized and as-cast alloys, although they have different critical strain amplitudes. The G-L theory is employed to explain the damping mechanism involving the interaction between the dislocation and the precipitated phase. In addition, a damping peak is observed at temperatures close to 330 °C for AZ31 magnesium alloy, which is related to the β-Mg₁₇Al₁₂ phase dissolution.