Microstructure and Mechanical Properties of the SiCp/A357 Composites Materials

In this study, SiCp/A357 composites containing 10% SiCp by mass were successfully fabricated using the semi-solid stir casting technique. The investigation focused on the microstructure, interfacial characteristics, and mechanical properties of the SiCp/A357 composites. The experimental findings indicated uniform distribution of SiCp within the matrix, with minimal interfacial reaction at the matrix and SiCp interface. Additionally, the interfacial bonding between SiCp and the matrix was found to be highly robust. The composites achieved an ultimate tensile strength of 233.4 MPa and an elongation of 7.67% prior to heat treatment. Following T6 heat treatment, the tensile strength showed significant improvement, reaching 431.9MPa, while the elongation decreased to 5.7%. The orientation relationship between the matrix and reinforcement was investigated, and first-principles calculations were employed to analyse the interfacial bonding between the reinforcement and the matrix. The simulations confirmed effective bonding, which consistent with the experimental observations.