Fracture toughness of different PVD coatings

Indentation technique was used to characterize the mechanical properties (elastic modulus, hardness and toughness) both of PVD coatings and autocatalitic chemical deposition ones. TiN and TiCN films were respectively deposited on a duplex stainless steel substrate using PVD technique; moreover a NiP films (P content about 8%) and a NiP/B4C composite ones were used as comparison materials. The effect of different substrate surface finishing (polishing and shot peening) was evaluated.