A unified model for determining hardness and Young’s modulus of thin films based on a revised Chicot–Lesage (1995) approach

A unified analytical model is proposed for the simultaneous determination of hardness and Young’s modulus of thin films from indentation measurements. The approach is based on the Chicot and Lesage (1995) composite hardness model, in which the original assumptions are revisited to improve the mechanical description of film–substrate systems. In particular, the evolution of the film contribution with indentation depth is reformulated, allowing a consistent extraction of both hardness and elastic modulus using a single framework. The revised model accounts for substrate influence without requiring multiple fitting procedures or independent elastic measurements. Validation is carried out on various representative thin film systems, showing good agreement with experimental indentation data and reference values. The proposed methodology provides a simplified and physically consistent tool for mechanical characterization of thin films, well suited for routine analysis.