Analysis of continuous stiffness data measured during nanoindentation of titanium films on glass substrate

An empirical function was proposed to describe the continuous stiffness curves, i.e., Er2/H versus h (where Er is the reduced modulus, H is the composite hardness and h is the indenter penetration depth), measured with nanoindentation tests for titanium films on glass substrate. By analyzing the variations of the parameters included in this empirical equation with film thickness, the physical meanings of this empirical equation were discussed. It was shown that the mechanical properties of the substrate and the film may be extracted from such analyses.