Use of scaling functions to determine mechanical properties of thin coatings from microindentation tests

The indentation of elastic±plastic coatings deposited on elastic substrates is studied in this work. The functional expressions that relate the load±indentation behaviour to coating and substrate material properties are derived using dimensional analysis in conjunction with ®nite element simulations. Based on these scaling functions, a method is proposed to determine the coating Youngʹs modulus, yield strength and strain hardening properties from the microindentation tests. A method to obtain improved estimates of the material hardness is also discussed. While the analyses are based on a conical (i.e. Rockwell) indenter, the indenter angle used in the simulations was selected so that the results can also be used to extract mechanical properties from measurements using the pyramidal indenters such as Vickers and Berkovich types