Application of infrared radiation heating method to evaluation of thermal shock resistance of cermet

Thermal shock resistance of cermets was tried to evaluate by the infrared radiation heating method that a thin circular disk is heated and fractured by infrared ray concentrated on the central area with a constant heat flux. Thermal shock fracture toughness R_2c could be measured for specimens with an edge notch, while thermal shock strength R_1c could not for the specimens without the notch. It was thought, however that R_2c might depend on radius of curvature of the edge notch. Using the data of R_2c, thermal shock strength R_1c was calculated from the consideration of stress concentration. As a result, it was considered that thermal shock strength R_1c could be applied to evaluation of thermal shock resistance of cermet ,and thermal shock resistance of Ti(C,N)-Mo₂C-Ni cermets increased with an increase in the content of nitrogen and Ni.