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

作　　者：Weiguo Li Fan Yang Daining Fang 

机构地区：[1]College of Resource and Environment Science, Chongqing University, 400030 Chongqing, China [2]AML, Department of Engineering Mechanics, Tsinghua University, 100084 Beijing, China [3]College of Engineering, Peking University, 100871 Beijing, China

出　　处：《Acta Mechanica Sinica》2010年第2期235-239,共5页力学学报（英文版）

基　　金：The project was supported by the National Natural Science Foundation of China （90505015 and 10702035）.

摘　　要：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 strength model 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.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 strength model 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.

关 键 词：Ultra-high temperature ceramics · Equivalent energy · Critical failure energy · Strength model 

分 类 号：TB33[一般工业技术—材料科学与工程] V254.2[航空宇航科学与技术—航空宇航制造工程]