Insights into thin film blistering of gold coating on metal substrate

•Blisters are observed in Au sputter-coating on Ni-based single crystal superalloy.•Their diameters increase, but diameter-to-height ratios don’t, with film thickness.•They prefer to form on the γ-matrix rather than the γ′-precipitate or Si substrate.•DFT calculations indicate a higher tendency of moisture adsorption on γ than on γ′.•Mechanical modelling shows blistering is driven by pocket of energy concentration.