Manufacture of porous SiC/C ceramics with excellent damage tolerance by impregnation of LPCS into carbonized pinewood

Porous SiC/C ceramics are manufactured by impregnation of a novel liquid polycarbosilane (LPCS) into carbonized pinewood under vacuum followed by ceramization. The morphology of the original pinewood structure is remained after ceramization without the formation of cracks and other defects. A high compressive strength of ∼37.23 MPa is achieved when the porous SiC/C ceramized at 1500 °C having an apparent porosity of ∼70 vol% and a density of ∼0.72 g/cm3. Investigation based on the Hertzian contact test demonstrates that the porous SiC/C ceramic is a “quasi-plastic” material. The originally shear-driven deformation contributes to its superior mechanical properties and is helpful in enhancing its damage tolerance. Our results highlight that the low density and high porosity SiC/C ceramic with superior mechanical properties and excellent contact damage resistance prepared by this new method is attractive for applications as light-weight structural and functional materials.