A multiscale model is being built in order to better understand and predict high-temperature corrosion and erosion properties of thermal spray coatings and materials in general. The approach uses molecular dynamics to predict diffusion kinetics, constrained free energy to determine reactions, and FEA to simulate structure. To obtain oxidation behavior data for validation, surface polished bulk materials and thermal spray coatings were exposed to various temperatures and exposure times. Oxidation depth and diffusion were assessed by optical emission spectroscopy and cross-sectional SEM examination and surface oxidation in grain and lamellae boundaries was characterized by 3D profilometry and SEM-EDS. Rough validation of the model was achieved using indentation test data, and a more complete validation will be done when high-temperature erosion test results are available.