High performance SiC/SiOC composites with in situ carbon interface

A novel SiC/SiOC composite was prepared via the polymer infiltration and pyrolysis (PIP) process by using a low-cost poly-methyl-silsesquioxane resin as matrix precursor and continuous thin SiC fibers as reinforcements. A carbon coating is in situ formed on SiC fiber prior to the composite processing. The high yield of the resin resulted in a short period of the composites achieving densification. The composites exhibited pseudoplastic fracture with a high flexural strength of 315.10 MPa and a fracture toughness of 21.6 MPa m1/2. With the help of the in situ coating, the SiC fibers pulled out of the matrix independently, leading to optimization of the rein-forcing effect and enhancement of the composite strength compared to chemical vapor deposition (CVD) fiber coatings. After annealing in N2 at 1000 degrees C for 10 h, the strength retention rate of the composites is 92.21%, showing excellent stability to be used in thermal structural components.