低热应力下石蜡对压装 RDX 基 PBX炸药性能的影响

摘要

To explore the effect of paraffin on properties of the pressed RDX-based PBX explosive containing aluminium powder under the low thermal stress,the micro-structures of the grains being heated at 55℃ for 57days were observed by scanning electron microscope,focus microscope,projection microscope and X-ray computed tomo-graphy.The volume,mass and density of the grain were measured and the vacuum stability,impact sensitivity, friction sensitivity and compressive strength and shear strength of the grain were performed.Results show that the paraffin in grain melts and connects to each other after being heated,the dispersed binder bond with each other and distributes evenly.The value of mass decreases by 0.1 %,the volume increases by 0.5% and the density decreases by 0.6% and the crack does not observed.The friction sensitivity changes from 8% to 0.The compression strength increases by 30% and the shear strength increases by 83%,showing that the low thermal stress doesn′t affect the impact sensitivity,stability and structure integrity of the grains.The softening migration of paraffin in grain under the low thermal stress makes the distribution uniformity,some of the initial micro-crevices of grain were repaired, which reduces the friction sensitivity of grain and increases the compression strength and shear strength.%为了解石蜡在低热应力下对压装含 Al 粉 RDX 基 PBX 炸药性能的影响，用扫描电镜、聚焦显微镜、透射显微镜、X 线断层摄影仪观察了药柱在55℃加热57d 的的微观结构；测量了药柱的体积、质量和密度，并测试了其真空安定性、摩擦感度、撞击感度、抗压强度、抗剪强度。结果表明，加热后药柱中石蜡软化连接，黏结剂互相粘结；药柱质量减少0．1％，体积增加0．5％，平均密度减少0．6％，未见裂纹；摩擦感度从8％降至0，抗压强度增加30％，抗剪强度增加83％。说明低热应力并未影响药柱的撞击感度、安定性和结构完整性，此时药柱中的石蜡发生软化迁移，分布均匀化，使药柱压制成型时的缺陷得到修复，从而降低了药柱的摩擦感度，并提高了抗压强度和抗剪强度。