Work-of-indentation as a means to characterize indenter geometry and load–displacement response of a material

Normalized indentation works, referred to as the total and elastic energy constants, have been shown to be effective in the representation and analysis of experimental load–displacement data. However, their physical meaning, influencing factors, variation range and relationships with other nanomechanical quantities are not precisely known. In this study, the load–displacement data obtained as a result of simulations of elastic and elasto-plastic indentations are extensively analysed to enhance our understanding concerning these two energy-based parameters. It has been shown that while the total energy constant describes the state of an indenter tip and the type of contact regime, the elastic energy constant characterizes the response of a material to indentation. In addition, their applications in the evaluation of key nanomechanical quantities such as the indenter tip radius, the nominal hardness and the contact depth are also discussed. (paper)