重熔时间对固溶态Ti@(Al-Si-Ti)p/A356 复合材料组织和性能的影响

A kind of particle-reinforced A356 aluminum matrix composite [Ti@ (Al-Si-Ti)p/A356] with "core-shell" structure was fabricated by powder thixoforming technique, and the composites formed for different reheating time were solid Solution treated at 545 C for 1 h. The effects of reheating time on microstructure evolution of the matrix alloy and "core-shell" structured particles, as well as tensile properties were investigated. The results indicate that with the increase of the reheating time, the primary a-Al particles in the solution-treated composites are continuously coarsened, and the eutectic morphology is spheroidized and coarsened with content decrease. The "core-shell" structured particles further react to thickening until the Ti core is consumed. The mechanical properties of solution-treated composites are desirable when reheating time is 40 min, where the yield strength, tensile strength and elongation is 172.1 MPa, 263.9 MPa and 20.0%, which is 7.3%, 11.7% and 12.4% higher than that of as-cast ones, respectively.