Elastic anisotropy of coatings by AFM analysis of microindentations

Atomic force microscope analysis of low load Vickers and Knoop indentation marks was performed to obtain a statistically consistent method for the mechanical characterisation of physical vapour deposition (PVD) coatings and the evaluation of elastic anisotropy. Indents shape analysis were elaborated with three different models for the evaluation of Young's modulus. Subsequently, roughness, elastic/plastic behaviour and intrinsic hardness have been numerically evaluated. Results showed that the intrinsic hardness evaluation of the films for applied loads as low as 50 mN is statistically supported by atomic force microscopy analysis of the indents, especially when diagonal length is smaller than 2/3 m. Moreover, some of magnetron sputtering PVDPlease confirm definition of MS. coatings showed mechanical anisotropy: normal to surface Young's modulus was higher than in plane Young's modulus. Such information would not have been obtained by nanoindentation testing alone and could be extremely important for the process development and production of high performance coatings for specific tribological applications. © 2014 Institute of Materials, Minerals and Mining.