BPN组分粒径对Slapper-BPN型EFDI发火感度的影响

Influence of Particle Size of BPN Components on the Ignition Sensitivity of the Slapper-BPN Type EFDI

为了研究硼/硝酸钾(BPN)组分粒径对Slapper-BPN型爆炸箔爆燃点火器(EFDI)发火感度的影响,设计并制备了由不同粒径的硼粉和硝酸钾组成的多个BPN配方,采用激光粒度仪表征了硼粉的粒径,讨论了硼粉粒径数量分布和体积分布的特点;通过扫描电镜(SEM)获得硝酸钾粒径对BPN药剂界面形貌的影响;根据差示扫描量热法(DSC)数据,计算了不同配方BPN的指前因子、表观活化能、最低热解温度和热爆炸临界温度,分析了BPN组分粒径对其动力学性能的影响;根据兰利法获得了不同配方BPN的临界发火电压及标准误差,讨论了BPN动力学性能和药剂界面形貌对其发火感度的影响。结果表明,BPN组分粒径主要从BPN的热分解性能和药柱界面形貌影响EFDI发火感度;BPN组分粒径变大,会使BPN药剂的最低热解温度变高,从而降低了EFDI发火感度;BPN组分粒径变小,改变了BPN药柱界面形貌,会使BPN药柱颗粒堆积更密实,减小药剂颗粒空隙,阻碍BPN的传火传热通道,在低密度装药条件下,会明显降低EFDI发火感度。因此,硼粉粒径一致性对低密度BPN发火感度的标准差具有一定影响。

To investigate the effect of the particle size of boron/potassium nitrate(BPN)components on the ignition sensitivity of Slapper-BPN type of exploding foil detonation initiator(EFDI),several BPN formulations consisted of boron powder(B)and potassium nitrate(KNO 3)with different particle sizes were designed and prepared.The particle size of B powder was characterized by a laser particle size analyzer,and the characteristics of the quantity and volume particle size distributions of B powder were discussed.The influence of KNO 3 particle size on the interface morphology of BPN agents were obtained through scanning electron microscopy(SEM).Based on the differential scanning calorimetry(DSC)data,the pre-exponential factor,apparent activation energy,the lowest thermal decomposition temperature,and the thermal explosion critical temperature of different BPN formulations were calculated,and the influence of BPN component particle size on its kinetic performance was analyzed.According to the Langlie method,the critical ignition voltage and standard error of different BPN formulations were obtained,and the effect of BPN kinetic performance and interface morphology of the agent on the ignition sensitivity were discussed.The results indicate that the particle size of BPN components mainly affect the ignition sensitivity of EFDI from the thermal decomposition properties of BPN and the interface morphology of BPN grain.The increase in particle size of BPN components makes the lowest thermal decomposition temperature of BPN agents increase and reducies the ignition sensitivity of BPN.The decrease in particle size of BPN components alters the interface morphology of BPN grain,resulting in a denser accumulation of BPN particles,reducing the gaps between particles and agents,hindering the heat transfer channels of BPN,which finally reduces the ignition sensitivity of EFDI under low-density charging conditions.Therefore,the consistency of B powder particle size has a certain impact on the standard deviation of low-density BPN ignition sensitivity.