In this work, the Al-10Si-2.5Cu-0.8Fe alloy was used as the base alloy to squeeze casting with different content Mg-10Al master alloy addition. The effects of microstructure and mechanical properties were investigated by XRD, OM, SEM, and tensile test analysis. The results show that with the increase of Mg addition, the morphology of eutectic Si in the alloy changes from strip to fiber and the size is obviously reduced. Al₈Mg₃FeSi₆ phase in the microstructure gradually grows, and the splitting effect on the matrix structure is increased. The tensile strength and elongation of the alloy increased first and then decreased with the increase of Mg content. When the Mg content is 1.38%, the tensile strength of the alloy reached a maximum of 289 MPa and the elongation is 2.24%. The hardness of the alloy gradually increases. When the Mg content is 2.51%, the hardness reaches 121.8 HV. The cleavage surface in the fracture becomes fine with the increase of Mg content, the number of dimples increases, and the fracture mode transitions from quasi-cleavage fracture to brittle fracture.

Safe and efficient recycling of industrially generated machined chips is a high-priority technological issue. In this study, the effect of SiC particles (SiCp) on the microstructure and mechanical properties of SiCp/AZ91D composites is systematically analyzed, and the reinforcement mechanism of SiCp on composites is investigated. Different contents of SiCp/AZ91D composites are fabricated by solid-state synthesis. The results show that the incorporation of SiCp refined the grains of SiCp/AZ91D composites, which is related to the uniform distribution of SiCp at the grain boundaries. The strong bonding of SiCp with the AZ91D matrix inhibited the generation and extension of cracks, which led to the simultaneous increase in the yield strength (YS) and elongation (EL) of the SiCp/AZ91D composites. The mechanical properties of the 3 wt.% SiCp/AZ91D composites are the most superior, with an average grain size, Vickers hardness, ultimate tensile strength (UTS), YS, and EL of 6.69 ± 4.48 μm, 89.5 ± 2.5 HV, 341 ± 11 MPa, 172 ± 8 MPa, and 4.43 ± 0.18%, respectively. The reinforcement mechanisms of SiCp/AZ91D composites are mainly grain refinement and dislocation strengthening. Solid-state synthesis is an effective method for recycling magnesium alloy chips.