Effects of pyrolysis temperatures on the microstructure and mechanical properties of 2D-Cf/SiC composites using polycarbosilane

Two-dimensional carbon fiber cloth reinforced silicon carbide (2D-Cf/SiC) composites were fabricated with polycarbosilane (PCS) and divinylbenzene (DVB) as precursors and SiC as inert fillers. The effects of the pyrolysis temperatures in the first cycle on the microstructure and mechanical properties of Cf/SiC composites were investigated. The results showed that increasing the pyrolysis temperature of the first cycle could weaken the interfacial bonding between carbon fiber and SiC matrix. As a result, the composites fabricated with higher pyrolysis temperature exhibit better mechanical properties. When the pyrolysis temperature of the first cycle was raised from 1000 °C to 1600 °C, the flexural strength, shear strength and fracture toughness were elevated from 200.7 MPa, 16.8 MPa and 7.4 MPa m1/2 to 319.2 MPa, 29.8 MPa and 15.0 MPa m1/2, respectively.