Microstructure and damping properties of Mg–Si binary hypoeutectic alloys

The effects of Si content and solution heat treatment on the microstructure and damping properties of as-cast Mg–Si hypoeutectic alloys were investigated. Si has the capacity to refine grains of pure magnesium. The three contents of Mg–Si hypoeutectic alloys are all high-damping alloys. The damping value of the as-cast Mg–0.5 wt-%Si alloy was higher than that of the Mg–0.3 wt-%Si and Mg–0.8 wt-%Si alloys in the small strain amplitude area. Compared to the as-cast state, the solution heat-treated Mg–Si hypoeutectic alloys show an increase in damping values, which are close to each other for the three contents in the small strain amplitude area, and decrease with increasing Si content in the high strain amplitude area as in the as-cast state.