AD95陶瓷的层裂强度及冲击压缩损伤机理研究

采用激光位移干涉测试技术测量了AD95 陶瓷在一维应变冲击压缩下的自由面或样品/窗口界面粒子速度剖面, 确定了层裂强度及其与加载应力的变化关系, 在此基础上讨论了冲击压缩损伤程度与加载应力的关系. 研究结果表明: AD95陶瓷发生冲击压缩损伤的阈值应力约为3.7 GPa, 小于其雨贡纽弹性极限(HEL, 约5.47 GPa); 小于阈值应力不发生冲击压缩损伤, 层裂强度随加载应力的增加逐渐增大; 大于阈值应力冲击压缩损伤快速发展, 层裂强度迅速降低; 在HEL附近层裂强度降低到零, 丧失了抗拉能力, 表明材料发生了严重的冲击压缩损伤.

The spall strength and shock compressive damage of AD95 ceramics

The relationship between spall strength and impact stress of AD95 ceramics which is in a one-dimensional strain state is determined by velocity profile measurement of the free surface or the sample/window interface. All fiber displacement interferometer system for any reflector is used in velocity measurement. Further the relationship between shock compressive damage degree and impact stress is discussed. The results indicate that the stress threshold of AD95 ceramics against shock compressive damage is about 3.7 GPa, which is less than its Hugoniot Elastic Limit (HEL, about 5.47 GPa). When impact stress is less than the threshold, no compressive damage occurs, and the spall strength increases with impact stress gradually. When impact stress is greater than the threshold, shock compressive damage occurs and develops rapidly which leads to the decrease of the spall strength with impact stress. The spall strength falls to zero when the impact stress increases up to about the HEL, which indicates that the material has lost the ability to resist the tensile stress and severe shock compressive damage has happened.