结构陶瓷的高温疲劳强度衰减理论  

High Temperature Fatigue Strength Degradation Theory for structure Ceramics

作　　者：金宗哲[1] 包亦望[1] 岳雪梅[1] 

机构地区：[1]中国建筑材料科学研究院高技术陶瓷研究所

出　　处：《高技术通讯》1994年第12期31-36,共6页Chinese High Technology Letters

基　　金：863计划资助项目

摘　　要：提出了陶瓷材料疲劳强度衰减理论并由此导出了各种疲劳关系式。建立了疲劳基本方程ｄσ＿ｒ／ｄ＿ｉ＝一Ａσ（ｔ）￣ｎｔ￣（－ｍ），得出了疲劳寿命公式Ｔ＝Ｍ（σ＿０－σ）／Ａσ￣ｎ（静疲劳时Ｍ＝１，连续增载疲劳时Ｍ＝ｎ＋１，循环疲劳时Ｍ＝（ｎ＋１）／（１＋Ｒ＋Ｒ￣２＋……＋Ｒ￣ｎ），逐级加载时，并导出不同疲劳方式下疲劳寿命间的关系。同时，用多种Ｓｉ＿３Ｎ＿４材料在高温中作了论证试验，结果与理论一致。Fatigue strength degradation theory for structure ceramics was presented and the relationshipe betweenfatigue strength and lifetime in various fatigue types were accordingly derived。 The basic fatigue equationwas formed as dσ_r/di=一Aσ(t)￣nt￣(-m)。 Fatigue lifetime was then derived as T=M(σ_0一σ)/Aσ￣n,where M=1for static fatigue,M=n+1 for steadily increasing loading fatigue,M=(n+1)/(1+R十R￣2+……+R￣n)for cyclic fatigue and for step Ioad fatigue。The relationships betweenthe lifetimes of different fatigue types were also derived. Tests at 1200℃on severaI Si_3N_4 materials and theresu I ts are in accordan ce with the theory.

关 键 词：强度衰减 疲劳 高温 陶瓷 结构陶瓷 

分 类 号：TQ174.758[化学工程—陶瓷工业]