Microstructure and mechanical properties of SiCnp/Al6082 aluminum matrix composites prepared by squeeze casting combined with stir casting

In this work, SiCnp/Al6082 aluminum matrix composites were prepared by squeeze casting (SC) combined with stir casting, and the effects of nano-sized SiC particles (SiCnp) and SC on microstructure and mechanical properties of the 6082 aluminum alloy were investigated. The result shows that the SiCnp were uniformly distributed in the 6082 aluminum matrix alloy using the stir casting. With the addition of the SiCnp, the microstructure of the 6082 aluminum alloy was obviously refined, up to 30.55% grain refinement compared to the 6082 aluminum alloy without the addition of the SiCnp. The as-cast ultimate tensile strength, yield strength and elongation of the SiCnp/Al6082 aluminum matrix composites were enhanced, which increased by 8.92%, 12.16%, and 12.60%, respectively, compared with the 6082 matrix alloy without the SiCnp. After the SC, the compactness of the SiCnp/Al6082 composites was significantly improved, and the grain of the composites was further refined. The ultimate tensile strength, yield strength and elongation of the SiCnp/Al6082 composites fabricated by the SC respectively increased by 29.81%, 43.18%, and 226.28%, compared to the 6082 aluminum alloy obtained by gravity casting (GC).