The temperature-dependent fracture strength model for ultra-high temperature ceramics

Breaking down the entire structure of a material implies severing all the bonds between its atoms either by applying work or by heat transfer. Because bond-breaking is indifferent to either means, there is a kind of equivalence between heat energy and strain energy. Based on this equivalence, we assume the existence of a constant maximum storage of energy that includes both the strain energy and the corresponding equivalent heat energy. A temperaturedependent fracture strengthmodel is then developed for ultrahigh temperature ceramics (UHTCs). Model predictions for UHTCs, HfB₂, TiC and ZrB₂, are presented and compared with the experimental results. These predictions are found to be largely consistent with experimental results.