Effects of Heat Treatment Process on Microstructure and Mechanical Properties of SiC_p Enhanced Al10SiMg Composites Prepared by Selective Laser Melting

SiC_p enhanced Al10SiMg composite was prepared using prect laser melting (SLM).The effects of different heat treatment processes on the microstructure evolution and mechanical properties of SiC_p/Al10SiMg composites were studied.The results show that, after T2 (artificial aging) treatment, the microstructure changes of composites are not obvious, but the mechanical properties are improved.After T6 (solid heat treatment+artificial aging) treatment, the copocrystalline silicon grid disappear, and the opersaturating Si particles are precipitated from the matrix to the soften Al matrix.The tensile strength and hardness of the composite are significantly reduced, but the elongation rate is improved.As the solid dissolution temperature increases (500-525℃), the Mg₂Si phase is first precipitated.The content of the intermetallic compound AlFeSi, at about 500 ℃increases with the solid dissolution temperature increasing.During T6 heat treatment, the hardness and tensile strength of the composite increase with the solid dissolution temperature increasing.The principle is that the precipitation of the Mg₂Si phase and the precipitation reinforcement of the intermetal compounds overcome the thickening of the microstructure and the softening of the matrix.