Fabrication of high density three-dimensional carbon fibre reinforced nitride composites by precursor infiltration and pyrolysis

Three-dimensional carbon fibre reinforced nitride composite materials were fabricated by precursor infiltration and pyrolysis using a hybrid precursor. The curing stage of precursor infiltration and pyrolysis was investigated and improved. The densification behaviour, mechanical properties and ablation properties of the composites were studied. The results show that high pressure curing method can be used to fabricate high density composites. With the increase of density from 1.50 to 1.65 g cm(-3), the flexural strength increases from 156.4 to 192.3 MPa, and the elastic modulus increases from about 45.9 to 56.3 GPa, while the linear ablation rate decreases from 0.069 to 0.056 mm s(-1). The load-displacement curves show that carbon fibres cause efficient reinforcement, and the composites have good toughness.