Effect of microwave melting on the microstructure and mechanical properties of Al-8.5Si-0.4Mg-0.7Cu alloy

The effect of microwave melting on the microstructure, melting process and mechanical properties of Al-8.5Si-0.4Mg-0.7Cu alloy was investigated in present study. Experimental results indicated that the phases of primary Si, eutectic Si, Mg2Si were observed in the as-cast alloy by microwave melting and the aluminides were mainly consisted of alpha-Al-7(Fe, Mn, Cu)(2)Si, Q-Al5Cu2Mg8Si6 and theta-Al2Cu. The grain size of the matrix was significantly refined since more phases of Mg2Si and Al2Cu were distributed on the aluminum substrate by microwave melting. The density and hardness of as-cast alloy by microwave melting were higher than that by conventional melting. The melting time by microwave could be shortened by 50% compared to by conventional melting. The energy consumption by microwave melting could be reduced 63.1% than that by conventional melting.