摘要
目的:研究口腔临床修复中WL和HT氧化锆陶瓷的弯曲强度可靠性和循环载荷下亚临界裂纹扩展(SCG)情况。方法:采用Weibull分布分析由三点弯曲强度实验获得的2组样本(n=15)的弯曲强度数据和由循环疲劳实验获得的2组样本(n=15)的循环疲劳断裂次数数据;通过帕里斯定律(Pairs Law)分析试样在循环载荷下的亚临界裂纹扩展情况,SCG行为通过疲劳裂纹扩展速率(da/d N)和最大应力强度因子(KImax)的函数关系来表述。结果:WL和HT的三点弯曲强度Weibull模数分别为10.64和12.04;应力腐蚀指数n分别为23.71和32.87;亚临界裂纹扩展(SCG)导致其失效的概率分别为90%和76.7%;发生亚临界裂纹扩展时的亚临界应力强度因子KImax仅相当于其临界应力强度因子的49.6%和50.9%。结论:WL和HT在循环载荷下存都在亚临界裂纹扩展,HT陶瓷的亚临界裂纹扩展的最低速率低于WL陶瓷(νHT<νWL)。
Objective：To evaluate the reliability of flexural strength and subcritical crack growth（SCG）of WL and HT zirconia ce-ramics under cyclic loading.Methods：Bar-shaped speciments of WL（n =30）and HT（n =30）were fabricated and loaded in three-point bending and cyclically fatigued.The flexural strength and the number of cycles to fracture were obtained from three-point flexural test and cyclic fatigue test respectively.Data were examined using Weibull statistics.Pairs law was used to analysize the subcritical crack growth（SCG）,the behavior of which was described in terms of crack velocity as a function of maximum stress intensity factor （KImax ）.Results：The Weibull module（m）of WL and HT was 10.64 and 12.04,the stress corrosion cracking susceptive indexes（n） 23.71 and 32.87,the SCG 90% and 76.7%,the KImax 49.6% and 50.9% of its maximum stress intensity factor（KIC ）,respectively. Conclusion：WL and HT produce pronounced SCG.The minimum fatigue crack growth rate of HT is lower than that of WL（νHT 〈νWL ）.
出处
《实用口腔医学杂志》
CAS
CSCD
北大核心
2015年第5期611-614,共4页
Journal of Practical Stomatology
关键词
牙科氧化锆陶瓷
Weibull分析
弯曲强度
循环疲劳
亚临界裂纹扩展
应力腐蚀指数
Dental zirconia ceramic
Weibull statistics
Flexural strength
Cyclic fatigue
Subcritical crack growth
The stress corrosion cracking susceptive indexes
