铵油炸药微观结构及其对雷管起爆感度的影响

Microstructures of ANFO and Their Effects on Detonator Initiation Sensitivity

炸药微观结构对性能影响显著,为更好认识铵油炸药(ANFO)微观结构及其对起爆感度的影响,采用扫描电镜法(SEM)和密度测试法表征不同状态铵油炸药颗粒的微观结构,通过切片技术观测ANFO炸药颗粒内部的微观特征,借鉴板痕试验原理测试样品雷管起爆感度。结果表明,未膨化ANFO炸药颗粒内部及外部孔洞和裂纹很少,颗粒表面较膨化ANFO炸药光滑;膨化ANFO炸药颗粒表面存在大量孔洞、裂纹和突起,表面凹凸不平,颗粒内部存在大量毛孔和孪晶。研究同时表明,膨化AN颗粒内的晶体生长过程并未进行完全。多孔的颗粒结构和凹凸不平的颗粒表面有利于提高ANFO的雷管起爆感度。

In order to understand the microstructures of ammonium nitrate-oil explosives（ANFO） and their effects on detonator initiation sensitivity, different types of ANFO were made from fuel oil and four different states AN, and the scanning electric microscopy （SEM） and density measuring method were both used to characterize their microstructures. Then, the section technique was used for the first time to observe their intragranular microstructures, and plate dent test was conducted to evaluate the detonator initiation sensitivity. Results show that unexpanded ANFO particles have few pores and cracks inside and outside of the particles, and its surface is more smoother than that of expanded ANFO particles. While expanded ANFO particles have many holes and cracks, there are abundant voids and twin crystals lying in the interior of expanded ANFO particles, and the growth of crystals is incomplete. The microstructures of porous particles and protruding particle surface are helpful to enhance the detonator initiation sensitivity of ANFO.