High performance SiC/SiOC composites with in situ carbon interface

Abstract

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 reinforcing effect and enhancement of the composite strength compared to chemical vapor deposition (CVD) fiber coatings. After annealing in N2 at 1000 °C for 10 h, the strength retention rate of the composites is 92.21%, showing excellent stability to be used in thermal structural components.