摘要
本文应用双扭法研究了四种电瓷材料静态疲劳裂纹扩展规律。试验结果表明:在空气介质中,所有试验电瓷材料均存在明显的裂纹亚临界扩展现象,且随裂纹尖端应力强度因子(K_1)增大呈现三个阶段关系。在不同介质中,裂纹扩展的敏感性按下列顺序变小:水、空气和煤油。试验还表明电瓷材料静态疲劳裂纹扩展规律与材料的配方、环境和受力等因素有关。
Crack propagation law under static fatigue state for some electric porcelains has been studied by means of double torsion specimens. Test results show that, with stress corrosion and unhomogeneity of microstructure cracks propagate easily under static loading if the applied stress is less than fracture stress. Cracks propagate mainly with microcracks, holes or cracking of glass phases in all electric porcelains. The relationship between crack propagation velocity(V) and crack-tip stress intensity(K_1) consists of three different stages. At the first stage(Ⅰ) there is a simple exponent relationship, namely: V=AK_1~n. On the basis of the above test,we suggest that the crack propagation law for all electric porcelains depends on sintering composition of test materials, environment and loading conditions.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1989年第2期125-130,共6页
Journal of The Chinese Ceramic Society
关键词
电工陶瓷
裂纹
扩展规律
electric porcelain
crack propagation
double torsion
stress intensity
