低速撞击下JO-8和B炸药的响应特性

采用30 kg小落锤对JO-8和B炸药进行了低速撞击加载试验,并对撞击过程和试验后样品分别进行了高速摄影和扫描电镜分析。撞击试验发现JO-8炸药的临界点火阈值为360 N,B炸药的阈值为300 N,这表明JO-8炸药具有更高的抗撞击能力;高速摄影发现两种炸药均经历冲击、塑性流动、飞散、反应等阶段,反应在炸药损伤后发生,JO-8炸药的反应滞后于B炸药;扫描电镜表明,B炸药在低速撞击下的损伤模式以界面脱粘、沿晶断裂为主,JO-8炸药以剪切变形和穿晶断裂为主。B炸药的制备工艺决定了TNT包裹RDX的微观结构,而TNT具有较低的晶体力学性能,导致其在加载下首先发生断裂;JO-8炸药的制备工艺决定了粘结剂包裹HMX晶体的微观结构,粘结剂改善了炸药晶体的脆性特征,致使JO-8炸的损伤模式不同;与B炸药相比,JO-8炸药发生点火延滞的原因在于JO-8炸药具有更高的压缩强度。

Response Characteristic of JO-8 Explosive and Composition B under Low-speed Impact

JO-8 and Composition B were investigated by low-speed impact loading test using the small hammer of 30 kg, and their impacting courses were studied by the high speed photography, and the residue after impacting were analyzed by the scanning electric microscopy(SEM). Results show that the ignition threshold of JO-8 is 360 N and that of Composition B is 300 N, which indicate that JO-8 has better anti-impact property than Composition B. Two explosives exercise shocking, plastic flowing, flying and reacting, and the reacting happens after the explosive is damaged with the residual explosive. The damage pattern of Composition B is focused on the interface debond and rupture across the crystal, and the JO-8 explosive is on the shear distort and rupture through the crystal. Because of the preparation process of Composition B, RDX is surrounded by TNT, and the lower mechanical properties of TNT cause the Composition B rupture under impact loading before that of JO-8. While the addition binder improves the brittle characteristics of the explosive HMX and made its damage pattern different from the composition B. The good compressed strength makes JO-8 explosive ignition delay.