Examining the mechanical properties of B4C/SiC hybrid reinforced 7075Al matrix composites using fast hot pressure sintering technique

Due to the limited improvement in ductility and strength of the Al matrix by single particle reinforcement, we have focused on hybrid particle-reinforced Al matrix composites in response to the increasing demand for better strength-ductility matching of ceramic particle-reinforced Al matrix composites. In this study, the B4C/SiC/ 7075Al composites were prepared from micron-sized B4C, SiC and 7075Al powders using powder metallurgy and fast hot pressure sintering technology. The microstructure, densification behavior and mechanical properties were investigated under different sintering conditions. It is demonstrated that the B4C/SiC particles hybrid reinforced 7075Al matrix composites were superior to that of the Al-based composites doped with single ceramic particles. The B4C/SiC/7075Al composites had the optimized mechanical properties at the sintering temperature of 460 degrees C and pressure of 150 MPa, and the hardness, flexural strength and fracture toughness reached 119 +/- 2 HRA, 501 +/- 26 MPa and 9.71 +/- 0.32 MPa & sdot;m1/2, respectively. The B4C/SiC/7075Al composites achieved simultaneous enhancement of strength and ductility, which was attributed to grain refinement, load transfer and geometrically necessary dislocations (GNDs) strengthening effects. This work highlights a promising strategy for designing novel particle-reinforced aluminum matrix composites with simultaneous strength and ductility enhancement.