ICME Simulation of APS Process and Damage in Ceramic Coatings

Abstract

Abstract This work shows an enhanced Integrated Computational Material Engineering (ICME) method for modeling of multi-material coating of Air Plasma Spray (APS) Ceramic Coating Process. ICME simulation of the APS process includes defects and the effect of defects (bending, curvature, delamination, and cracks), in-service analysis under Burner-Rig and furnace thermal loading conditions, and the effect of high temperature on Thermal Barrier Coatings (TBC) over the metallic substrate of dog bone specimens to demonstrate durability and damage tolerance (D&DT). To achieve this end, a multi-physics-based ICME methodology and virtual design of experiment (DOE) tools are developed to virtually generate multi-layered materials including high-temperature coatings for use in engine/aircraft high-temperature exhaust regions. The ICME innovation centers around: 1) Thermo-Physics Modeling (plasma, vapor, liquid, solid) to predict the material’s thermal profile, voids, densities, and thermal conductivities; 2) Multiscale Material Modeling of the top coat, bond coat, and substrate to predict material performance: a) temperature-dependent strength, stiffness, residual stresses and strains considering the effect of defects, and b) rumpling, surface waviness, and Thermal Growth Oxidation (TGO); 3) Structural Analysis and D&DT to predict coating and substrate failure evolution (i.e., delamination, oxidation, etc.) during thermo-mechanical in-service loading; and 4) Simulation of residual stress/strains due APS process. The simulation also shows rumpling and TGO growth have little effect on the as-built APS TBC specimen. Verification was performed using test data on TBC/Haynes230 systems under thermal loading. Tests and predictions were in close agreement. Both test and prediction showed an as-built specimen exhibiting bending during APS process and delamination during Burner-Rig testing.