无机材料学报

• 研究论文 • 上一篇    下一篇

陶瓷的断裂韧性与缺口半径 Ⅰ.断裂韧性测试技术

王锋会; 刘 (韦华)++; 路民旭+; 郑修麟   

  1. 西北工业大学材料科学与工程系; 西安710072; + 西安石油管材研究中心; 西安 710068; ++西安建筑科技大学力学教研室
  • 收稿日期:1995-10-18 修回日期:1995-12-07 出版日期:1997-02-20 网络出版日期:1997-02-20

Fracture Toughness of Ceramics and Notch Radius Ⅰ. Fracture Toughness Testing Technique

WANG Fenghui; LIU Wei++; LU Minxu+; ZHENG Xiulin   

  1. Department of Materials Science and Engineering; Northwestern Polytechnical Universify Xi an 710072 China; +Xi ar Tubular Goods Research Center Xi an 710068 China
  • Received:1995-10-18 Revised:1995-12-07 Published:1997-02-20 Online:1997-02-20

摘要: 本文用一种新的简单方法制备了不同半径的尖缺口,用单边切口梁试件测试了不同缺口半径氧化铝陶瓷的断裂韧性.对七种不同测试方法测得的、同一种材料的断裂韧性进行了对比,讨论陶瓷材料断裂韧性的最佳测试方法和测试中对缺口半径的要求.

关键词: 陶瓷材料, 断裂韧性, 缺口半径

Abstract: The dependence of Kic on the notch-root radius was tested with the notch radius as small as a few micrometers in a polycrystalline alumina ceramics. The results show that the fracture toughness decreases as the notch radius decreases, when the notch radius approximately equal, to or lowcr than the average grain diameter, the fracturc tonghness becomes constant, this implies that the critical notch tip radius has the same sizc as the average grain diameter. The fracture toughness of a same alumina was also tested by seven different methods, ie.e. bridge indentation, compressive cyclic fatigue, precrack before sintered and polished sharp notch methods with the SENB specimens; wedge press and precrack before sintered methods with DCB specimens; indentation method with disc. the results show that SENB specimens with polished sharp notch or compressive cyclic fatigue precrack yield the true Kic value.

Key words: alumina, fracture toughness, sharp notch