Interconnected SiC–Si network reinforced Al–20Si composites fabricated by high pressure solidification

The microstructures and mechanical properties of the interconnected SiC–Si network reinforced Al–20Si composites solidified under high pressures were investigated. The results demonstrate that the complete interconnected SiC–Si network can be obtained by high pressure solidification, and the connected micron-sized pores are uniformly distributed in the interconnected SiC–Si network. The compressive strength and microhardness of the SiC/Al–20Si composites solidified under 3 GPa were 723 MPa and 229 HV_0.05, respectively. Furthermore, the fracture process of SiC/Al–20Si composites was studied by in situ TEM tensile testing. The result shows that the crack first initiated and propagated at the Al/Si interface under an external load, and the SiC particles in the interconnected SiC–Si network can effectively hinder the crack propagation, thus enhancing the strength.