2016 Volume 2 Pages 16-00436
It is known that thermal resistance exists at interfaces in bonded dissimilar materials due to imperfect mechanical and chemical bonding as well as phonon scattering at the interface. This thermal resistance influences the temperature distribution as well as thermal stresses in the bonded material. The purpose of this work is to explore the effect of interfacial thermal resistance on thermal fracture behavior of bonded materials. In particular, we consider an edge crack in the coating layer that is bonded to a substrate. The thermal stress intensity factor for the edge crack considering the thermal resistance at the coating-substrate interface is calculated using an integral transform/integral equation method. The numerical results for an Al2O3 coating on a Si3N4 substrate show that the thermal stress field deviates from that for the coating/substrate system without considering interfacial thermal resistance. The thermal stress intensity factor is increased by the interfacial thermal resistance, which indicates that the thermal shock resistance of the coating/substrate system can be degraded by the presence of thermal resistance at the interface between the coating and substrate.
