Hard coatings

The terminology ‘hard coatings’ can be used in generic sense to include all coatings providing requisites resistance to the specific use environment. Thus ‘hard coatings’ would include not only tribological coatings but also optically hard coatings used in high power lenses, electronically hard coatings used in radiation environment, etc. In this paper we discuss ‘hard coatings’ in this general sense to show the common structure/property correlations determining the environmental resistance of these coatings in specific applications.