Effect of hybrid reinforcement on microstructure and mechanical properties of AZ61 magnesium alloy processed by stir casting method

In this present study, AZ61 magnesium alloys reinforced with a low weight fraction of alumina (Al2O3: 2 wt %) and silicon carbide (SiC: 0.5, 1, 1.5 wt %) nanoparticle hybrid composites were fabricated using the gravitating mechanical stir casting (GMSC) method. The microstructure analysis reveal a monolithic alloy structure composed of alpha-Mg grains with intermetallic secondary (beta-Mg17Al12) phases uniformly distributed at the grain boundaries. The addition of reinforcements to the monolithic alloy reduces their mean size and leads to a breaking down of the beta-Mg17Al12 phases from round to needle like in shape. The hardness, tensile and compressive strength results show a direct relationship with the SiC reinforcement contents, the maximum values obtained the addition being 1 wt% SiC along with AZ61+2 wt%Al2O3 hybrid composite.

Automated summary

The present study found that adding alumina and silicon carbide nanoparticles to AZ61 magnesium alloys can improve the microstructure of the alloy and enhance its hardness, tensile, and compressive strength. The optimal performance was observed when the SiC reinforcement content reached 1wt% in the hybrid composite.