Fabrication, microstructure and high temperature stability of carbon fiber reinforced SiYOC composites

Abstract Continuous carbon fiber reinforced SiOC composites (C/SiOC) show promise for high-temperature application. Whereas, the high temperature resistances of SiOC ceramic matrix and carbon fiber are mismatched, which significantly restricts the long-term application of C/SiOC composites at high temperatures above 1250 °C. In this paper, heterogeneous element Y was introduced in C/SiOC composite by taking Y-doped MK resin as raw material to modify the structure of the SiOC ceramic matrix. Characteristics and high temperature evolution behaviors of SiYOC ceramic matrix in the inert environment were investigated. The microstructure, mechanical properties and high-temperature evolution of C/SiYOC composites were analyzed. The density, flexural strength and fracture toughness of the as-fabricated C/SiYOC composites were 1.89 g/cm3, 261.7 MPa and 13.54 MPa•m1/2, respectively. In the process of high-temperature treatment, the mechanical properties of C/SiYOC composites decreased obviously at 1500 °C due to the decomposition of SiYOC ceramics matrix and the carbothermal reductions between matrix and fibers.