Mechanisms of destruction of plasma-sprayed heat protecting coatings in heat cycling

The article presents the results of heat cycling tests of plasma-spayed heat protecting coatings consisting of two layers: a lower metal layer based on the alloy CoCrAIY, and an upper ceramic layer based on zirconium dioxide. To stabilize the ZrO₂ partially, the following additives were used: 30% CeO₂, 8% Y₂O₃, 6.2% Y₂O₃. The article examines the conditions of crack propagation on the metal-ceramic interface in dependence on the thickness of the ceramic layer. It is noted that it is expedient to provide an interface between metal and ceramic with nonuniform adhesive bond so that there are sections with higher resistance to the development of destruction.Translated from Problemy Prochnosti, No. 2, pp. 44–47, February, 1994.