增韧氧化铝陶瓷的层裂强度及压缩损伤研究

采用一级轻气炮对增韧ZTA 95/10陶瓷进行一维应变冲击压缩,通过激光干涉测速技术测量样品的自由面速度剖面,计算经过冲击压缩后残余的层裂强度,分析了其与加载应力的关系,并与未增韧的AD95陶瓷进行了对比,讨论了冲击压缩损伤程度随加载应力的变化关系以及增韧效果. 结果表明:加载应力在其雨贡纽弹性极限σ_HEL(约4.1 GPa)以下,ZTA 95/10陶瓷的层裂强度基本稳定,平均值为0.39 GPa,材料未发生压缩损伤;超过σ_HEL,层裂强度逐渐降低,开始发生压缩损伤;层裂强度在1.5倍σ_HEL附近降低到0,表明压缩损伤程度比较严重. 与AD95陶瓷相比,加载应力在3.7 GPa(AD95陶瓷的冲击压缩损伤阈值应力)以下,两种陶瓷的层裂强度基本相当;加载应力进一步增大,AD95陶瓷的层裂强度快速降低,而增韧后的ZTA 95/10陶瓷的层裂强度下降并不明显,表明ZTA 95/10陶瓷的压缩损伤程度远小于AD95陶瓷,这在一定程度上体现了增韧效果. 

The Spall Strength and Shock Compressive Damage of ZTA 95/10 Ceramics

ZTA 95/10 ceramics were shocked under one dimensional strain by light gas gun. The free surface velocity profiles were measured by laser interferometer system. Further the residual spall strength and shock compressive damage were discussed and compared with AD95 ceramics. Results indicate that when impact stress is less than σ_HEL(about 4.1 GPa), the spall strength of ZTA 95/10 is stable and the average value is 0.39 GPa, which means that there is no compressive damage occurred; when impact stress is greater than σ_HEL, the spall strength decreases gradually, which means that damages begin to generate; the spall strength falls to zero at about 1.5 times of σ_HEL, which implies that severe damages have generated. Compared with AD95 ceramics, we can see that when impact stress is less than 3.7 GPa (the stress threshold of AD95 ceramics to shock compressive damage), the spall strengths of ZTA 95/10 and AD95 are equivalent; with the increase of impact stress, the spall strength of AD95 decreases rapidly, while the decrease of spall strength for ZTA 95/10 is unconspicuous, which indicates that the compressive damage of ZTA 95/10 is not severe as that of AD95.