Study on the Preparation of Al2O3/Al-15Si-4Mg composite material

In this research, microstructure refinement treatment was carried out by adding different content of lanthanum to Al-15Si-4Mg alloy. The effect of heat treatment process on the alloy after metamorphism was studied, and the optimal performance matrix was selected for A12O3/Al composite research. The results show that La has good metamorphism effect on Al-15Si-4Mg alloy. With the increase of La metamorphic agent content, the eutectic silicon structure was obviously refined. When the La content reached 1wt.%, the refining effect was the best. The hardness of the alloy was 111HBS. When the optimum amount of La was 1wt.%, the XRD phase and EDS spectrum analysis show that the alloy without modification was mainly composed of Al, Si and Mg2Si, and the metamorphic alloy also forms a rich La phase. The mechanical properties can be significant improved by the heat treatment process. After the heat treatment, the acicular structure of the eutectic silicon structure became smooth and smooth, which reduced the splitting effect on the aluminum matrix. The hardness was 113HBS. The toughness of the material can be significantly improved by the heat treatment process. The sample with 1wt.% La was selected as the matrix of the A12O3/Al composite. A12O3 Al was prepared by liquid sintering method and no rich La phase but MgAl2O4 was found near the interface which is well reactivate wetted.