Application of hertzian tests to measure stress-strain characteristics of ceramics at elevated temperatures

Abstract

A new method for evaluating the elastic-plastic properties of ceramics from room temperature up to the onset of creep based on Hertzian indentation testing is proposed. Indentation stress-strain curves are compiled for representative alumina and zirconia ceramics at prescribed temperatures. Deconvolution of the indentation stress-strain curves for each material provides a measure of Young's modulus, yield stress, and work-hardening coefficient as a function of temperature, enabling construction of true stress-strain curves. The stress-strain curves flatten out with increasing temperature, in accordance with an expected increased plastic response at elevated temperatures. © 2006 The American Ceramic Society.