Thermal shock resistance of ceramic coatings

A methodology is established for the evaluation of the thermal shock resistance of ceramic coatings. The problem is formulated by considering a thin coating to a thick substrate subjected to a sudden cooling on the coating surface. Time-varied thermal stresses and stress intensity factors for various parameters of the problem are obtained. The crack initiation behavior and the thermal shock resistance of the coating are studied. The crack length dependency behavior of the thermal shock resistance of the coating is discussed. Two critical size parameters, which control the applicability of the stress-based criterion and the fracture mechanics-based criterion to the determination of the thermal shock resistance of coatings, are explored.