Elevated temperature strength and thermal shock behavior of hot-pressed carbon fiber reinforced TiC composites

In order to improve the elevated strength and thermal shock resistance of TiC materials, 20vol% short carbon fiber-reinforced TiC composite (Cf/TiC) was produced by hot pressing. With carbon fiber addition, the strength and fracture toughness of TiC is increased remarkably, and the elastic modulus and thermal expansion coefficient are decreased. The strength value of Cf/TiC composite is 593 MPa at room temperature and 439 MPa at 1400°C, and the fracture toughness value at room temperature is 6.87 MPa m1/2. The thermal stress fracture resistance parameter, R, thermal stress damage resistance parameter, RIV, and thermal stress crack stability parameter, Rst, are all increased. The residual strength decreases significantly when the thermal shock temperature difference, ΔT, is higher than 900°C, and the residual strength is 252 MPa when ΔT is 1400°C. Carbon fiber reinforced-TiC composite exhibits superior resistance to thermal shock damage compared with monolithic TiC. The catastrophic failure induced by severe thermal stresses can be prevented in Cf/TiC composite.