Nanomechanics to 1000 °C for high temperature mechanical properties of bulk materials and hard coatings

Abstract

It is important to measure nanomechanical properties of materials for extreme environments at temperatures that match their operating conditions so that the data are more relevant than those obtained from room temperature measurements. Reliable high temperature mechanical property data improves our understanding of the linkage between the small-scale mechanical behaviour and the performance and design of advanced materials systems for increasingly extreme environments. Accurate high temperature nanomechanical measurements require significantly more careful instrumental and experimental design than at room temperature. It is important to consider (i) instrumental stability and thermal drift (ii) the test environment and its influence on the stability of the indenter and sample (iii) modifications to the experimental load history and analysis procedures to minimise the effect of greater time-dependency. In this review of best practice and published studies effective strategies for mitigating these effects and achieving reliable, validated data are discussed with illustrative examples on thin films and bulk materials operating in extreme environments in applications in the nuclear, aerospace, fuel cell and cutting tool industries to 1000 °C.