摘要
准确测试陶瓷材料断裂韧性K_(IC)的关键是预制具有原生裂纹的试样。本文首先对桥压法预制原生裂纹进行了研究,然后针对桥压法存在的问题提出了一种简便而有效的陶瓷材料原生裂纹的预制方法——静态膨胀法。研究结果表明:静态膨胀法中裂纹的扩展是稳态的;通过调节影响膨胀剂压力的多种因素,可以准确地控制裂纹扩展的深度,预制出合适的原生裂纹,对几种陶瓷材料试验后得到了满意的结果。为准确评价结构陶瓷的断裂韧性提供了一种有效可行的方法。
The specimen with natural sharp cracks are important for measuring the fracture toughness KIC of structural ceramic materials. In this paper .bridge-indentation method is adopted to precrack in ceramic specimens, and the advantage as well as disadvantage are discussed. A new method, the static-expansion (SE) method to precrack is devised. The results show that the crack growth is stable in SE method and the precrack length of specimens can be accurately controlled by adjusting the factors effecting on the static expansive a-gent. It provides a effective means to evaluate accurately the fracture toughness of ceramic materials.
基金
国家自然科学基金(59302017)
关键词
断裂韧性
桥压法
静态膨胀法
结构陶瓷
力学性能
fracture toughness
precrack
bridge-indentation method
static-expansion method
