Effect of Pre-Crack Size and Testing Temperature on Fatigue Strength Properties of Crack Healed Mullite.
Effect of Pre-Crack Size and Testing Temperature on Fatigue Strength Properties of Crack Healed Mullite.
复制标题
预裂纹尺寸和测试温度对裂纹愈合莫来石疲劳强度性能的影响。
DOI：
10.2472/jsms.50.920
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Shigemi Sato
中科院分区：
文献类型：
--
作者：
K. Ando;Kiichi Tuji;K. Furusawa;Tuyoshi Hanagata;M. Chu;Shigemi Sato
根据JIS标准对莫来石/碳化硅复相陶瓷进行了烧结和三点弯曲试验。每个试件均形成直径为100~200μm的半椭圆形表面裂纹。通过三种试件(光滑试件、裂纹试件和裂纹愈合试件)在室温下系统地测定了裂纹的愈合行为和循环疲劳强度。并对其在室温、700℃和1000℃下的静态疲劳强度进行了系统的测试，主要结论如下：(A)莫来石/碳化硅复相陶瓷具有修复裂纹的能力。(B)裂纹愈合后的试件表现出比未愈合试件更高的循环和静态疲劳强度，这是由裂纹愈合引起的。(C)裂纹愈合部分具有足够的疲劳强度，且大部分断裂发生在裂纹愈合区域之外。(D)裂纹愈合后的试件在室温下具有足够的循环疲劳和静态疲劳强度。(E)裂纹愈合样品在700℃和1000℃下的静态疲劳强度与室温下的值相似。
Mullite/SiC composite ceramics was sintered and subjected to three-point bending on specimens made according to the appropriate JIS standard. Semi-elliptical surface crack of 100-200μm in diameter was made on each specimen. By using three kind of specimens (smooth, cracked and crack healed), crack-healing behavior and cyclic fatigue strengths were determined systematically at room temperature. And static fatigue strengths was determined systematically at room temperature, 700°C and 1000°C. The main conclusions obtained are following: (a) Mullite/SiC composite ceramics has ability to heal a crack. (b) Crack healed specimen showed higher cyclic and static fatigue strength than as-received specimen, and this fact was caused by crack healing. (c) Crack healed part has enough fatigue strength and most fracture occurred outside the crack-healed zone in crack-healed specimen. (d) Crack-healed specimen has a sufficient strength for cyclic fatigue and static fatigue at room temperature. (e) The static fatigue strength of crack-healed samples at 700°C and 1000°C were similar to the values at room temperature.