A dual triangular pyramidal indentation technique for material property evaluation

In this study, a method using dual triangular pyramidal indenters is suggested for material property evaluation. First, we demonstrate that the load-depth curves and the projected contact areas from conical and triangular pyramidal indentations are generally different. Nonequal projected contact areas of two indenters and nonplanar contact line of Berkovich indenter are the main sources of different indentation characteristics of two indenters. For this reason, an independent approach to the triangular pyramidal indentation is needed. With finite element (FE) indentation analyses for various materials, we investigate the relationships between material properties, indentation parameters, and load-depth curves. Based on the FE solutions, we suggest mapping functions for evaluating material properties from indentations by two triangular pyramidal WC indenters, which differ in their centerline-to-face angles. Elastic modulus, yield strength, and strain hardening exponent are obtained with an average error of <3%.