Microstructure and mechanical properties of 3D-net SiC/Zr amorphous matrix composites

The 3D-net SiC/Zr amorphous matrix composites reinforced by porous ceramic were fabricated using pressure-infiltration-quenching method. The phase structure, interfacial morphology and failure surface were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA), and the effect of the 3D-net SiC preform on the structure of the composites and the effect of interfaces on mechanical properties of the composites were discussed. The results show that ceramic preform is composited with Zr to form cross-net structure with double continuous phase. The diffusion distribution of elements(Si and Zr)in interfacial field indicates that there is a diffusion layer between ceramic phase and the matrix with the thickness of about 1 μm. The interfacial bond mechanism of 3D-net SiC/Zr amorphous matrix composites includes mechanical combination and diffusion bond, and the strength of interface combining strength and toughness of composites is appropriate. The destroy of the 3D-net SiC is the main factor leading to the fracture of the composites, and viscous folw existing in the amorphous alloy acts as bridging agent during crack extension.