Heat treatment effect on the damping capacities of Mg₂Si/AZ91D composites

Abstract

10 wt% of fly ash cenospheres (FAC) powder fragments with average size of 200 μm were added to the AZ91D Mg alloy slurry to prepare Mg₂Si/AZ91D composites by stirring casting method. Then solution treatment was carried out for the composites. The effects of the solution treatment at 420°C on the morphology of Mg₂Si particles and damping capacities were discussed. The results showed that after the solution treatment, the distribution of Mg₂Si particles in the composite becomes more uniform, and the damping capacities are higher than those of as-cast composite. The results of damping capacity revealed that damping of composites at room temperature is dependent on strain, and can be explained by G-L dislocation theory. At elevated temperatures, interface damping becomes a new contributor to the damping capacity. After the solution treatment, the distribution of Mg₂Si particles in the composite becomes more uniform, and the damping capacities are higher than those of as-cast composite.