An indentation hardness-testing temperature model for ceramics and tungsten carbides

This article describes an indentation hardness-temperature model based on a Kachanov-type damage law. The indentation hardness of materials varies with testing temperature. It is found that the surface area of the indentation increases exponentially with the testing temperature during hardness measurements. The change rate of the total contact area of the resulting indentation can be described as a function of the indentation area itself. Two parameters, a softening coefficient and an exponent, are able to determine the change rate of the indentation area with the testing temperature. In particular, the softening coefficient is found to increase as the film thickness increases. This proposed model will enable tribologists to predict the indentation hardness of materials and quantify the influence of various factors affecting indentation hardness.