Corrosion behavior of CVI 2D C_f/SiC composites under high temperature burner rig tests

The two dimensional (2D) C_f/SiC composite specimens prepared by chemical vapor infiltration (CVI) were tested at high temperature under burner rig tests. The surface physicochemical properties and microstructure characteristics of the specimens before and after 1400 °C gas frontal impact were analyzed to propose the corrosion and damage mechanism. The results show that the carbon fibers and SiC matrix on the surface of the specimens exposed to combustion gas were oxidized successively, and the specimens showed a weight loss due to the corrosion and oxidation underhigh-temperature wet oxygen environment. The notches of exposed carbon fibers at the edge and the crack developments caused by the thermal expansion mismatch between the fiber and the matrix can cause the oxidation failure of carbon fibers, resulting in similar matrix spallings.