The influence of the mechanical properties of a steel substrate on the macroscopic strength of a coated material

The stress-strain localization and fracture in a steel substrate – porous ceramic coating microstructure subjected to compression – is investigated numerically. The effects of the substrate grain size and coating-substrate interface geometry on the mechanical behavior of the coated material are discussed. The elongation of the microstructure for which the first crack is initiated in the coating (crack initiation strain) is shown to increase exponentially with an increase in the substrate grain size. The location of the first crack in the coating is found to vary with the substrate grain size. The strength properties of the composite material are found to be unaffected by a serrated coating-substrate interface.