Mechanical Properties of Porosity-Free Beta Tricalcium Phosphate (<i>β</i>-TCP) Ceramic by Sharp and Spherical Indentations

Abstract

Instrumented indentation has been developed for determining the mechanical properties of materials but an accurate determination of these properties requires attention on contact stiffness analysis, indentation size effect, elastic modulus mode of calculation, role of stress distribution around the indent and its introduction in expanding cavity models for tensile mechanical properties determination. In the present work, models for hardness, elastic modulus and plastic properties determination by indentation are briefly reviewed and applied for the characterization of a porosity-free β -TCP bioceramic. As a main result the elastic modulus is found to be equal to 162 GPa resulting from the application of different approaches based on the use of various sharp and spherical indenters. Additionally, Martens and contact macrohardnesses were found to be independent on the dwell-time and equals to 4.1 and 6.3 GPa, respectively. Finally, models based on Hollomon’s and Ludwik’s laws as well as expanding cavity models were critically analyzed in light of their capacity to determine the yield stress and to represent the behavior law of the material. As a main result, the yield stress of the β -TCP is found to be equal to 2 GP a.