Interfacial Blister Evolution of Coated Surfaces Under Severe Thermal and Pressure Transients

Abstract

The effects of severe thermal- and pressure-transients on coated substrates with indentation-induced, blister defects were analyzed using experimental and finite-element methods. An explicit FEA approach was first used to assess the transient thermal- and stress-states and the propensity for fracture related damage and evolution, under uniform convection and pressure transients across the surface; cohesive zone properties were evaluated in a previous study before being applied in an implicit indentation simulation. The indentation simulation results then served as the initial conditions for explicit modeling of interfacial flaw evolution due to thermal and pressure transients. Various conditions were analyzed including thermal and gun tube boundary conditions, and the effects of coating thermal capacitance. Given the need for robust coatings, the experimental and modeling procedures explored by this study will have important ramifications for coated tube design.