陶瓷材料断裂韧性与缺口半径　Ⅱ　断裂韧性估算方法  

Fracture Toughness of Ceramics and Notch Radius Ⅱ Fracture Toughness Predicting Method

作　　者：王锋会[1] 郑修麟[1] 路民旭 孙中禹 

机构地区：[1]西北工业大学材料科学与工程系,西安710072 [2]西安石油管材研究中心,西安710061 [3]空军通讯工程学院,西安710070

出　　处：《无机材料学报》1997年第2期218-228,共11页Journal of Inorganic Materials

基　　金：航空科学基金

摘　　要：在陶瓷材料裂纹尖端存在一个断裂过程区，当断裂过程区内平均应力达到断裂强度时．裂纹扩展．本文由理论推导并结合实验数据．得到了断裂过程区的大小是平均晶粒直径的四倍．并由平均应力断裂模型，给出了陶瓷材料断裂韧性和缺口半径及平均晶粒直径之间的关系式，由此关系式可以用宽缺口试件测出的断裂韧性去估算陶瓷材料的本质断裂韧性．Because of the technical diffculty to create an ideal plannar crack with zcro root radius, macronotchedspecimen are of ten prepared for testing the fracture toughness of ceramics. In this paper, the quantitativeexpression of fracture toughness of ceramics and notch radius was investigated. Based on the theory thatthere exists a fracturc proccss zone in front of crack tip and average stress fracture model, a relationbetween fracture toughness and notch radius was derived, with this relation, the fracture toughness ofceramics can be predicted from tested value of macronotched specimens. Combined the fracture processzone with the experiment results from the available literature, it is showed that the scale of fracture processzone is four times of average grain diameter. Compared with the experimental results, we have a conclusionthat when the notch radius reach to the average grain diametcr, the tested results can yield the true valueKIc under 6% deviation.

关 键 词：缺口半径 断裂 韧性 估算模型 陶瓷材料 

分 类 号：TQ174.15[化学工程—陶瓷工业]