Oxidation-induced stresses in ceramic-metal interfaces

The oxidation-induced stresses, which are known to control the interface de gradation and eventual failure of ceramic-metal interfaces at high temperat ures, are calculated using a constitutive framework coupled with the diffus ion of oxidant species through a multi-phase solid. The proposed constituti ve model accounts for the phase transformation associated with the oxidisin g phase, and incorporates the effect that the local volumetric expansion of the newly formed oxide has in the generation of inelastic volumetric strai ns and stresses. The formulation is implemented into the finite element met hod and used to investigate the evolution of the interfacial stresses induc ed by the gradual oxidation of a typical thermal barrier coating system.