Influence of residual stresses on thermal stress resistance of refractory ceramic

The conditions of formation of residual stresses (RS) in a thermo-loaded ZrC disk at the cost of relaxation of thermal stresses are considered. The creation of RS was carried out during the heating of samples by an electron beam and induction methods at different rates in a range 1600–2300 K. The kinetics of formation and distribution of RS depending on temperature, nonuniformity of the temperature field and temperature exposure period is investigated. The influence of the sign and level of residual stresses on the thermal stress resistance and fracture character are established. Acceptable modes of thermal loading, eliminating sample fracture under RS or the formation of a favourable stress field increasing the thermal stress resistance are defined.