In-situ study of the fracture behavior of SiCf/SiC composite material under three-point bending

Abstract

The mechanical properties and fracture behavior of a SiCf/SiC composite material were studied by in-situ three-point bending testing. The deformation and cracking behavior of SiCf/SiC composite material was captured by the equipped scanning electron microscope. The experimental results indicate that the fracture property was highly related to the microstructure of the matrix and the SiC fibres. The in-situ observation showed that the composite material exhibited complex crack initiation and propagation process under three-point bending. Vertical microcracks initiated at the root of the preset notch and propagated vertically till blocked by the horizontal fibers. Driven by the large loca stress, horizontal cracks were also found initiated adjacent to the notch root and propagated horizontally along the interface between the fibers and the matrix.