Mechanism of plastic deformation of powder metallurgy metal matrix composites of Cu–Sn/SiC and 6061/SiC under compressive stress

Under compressive stress, the plastic deformation mechanism of the powder metallurgy (P/M) process metal matrix composite (MMC) varies with the bonding strength of interfaces. The strength of the bonds among the matrix particles, the particle size distribution, and the bonding strength between the matrix particles and the reinforcement dominate the mechanical behaviors of MMC. In this study, simple metal and reinforcement powder were simulated as globular particles in the structure. The different combinations of these globular particles were used to elucidate the mechanism of plastic deformation of metal matrix composites under loaded by compressive stress. Two types of deformation mechanisms operate, depending on the bonding strength of the grain boundary—“grain deformation” and “boundaries slip”. Additionally, the experimental results verified the accuracy of the plastic deformation mechanism proposed herein.