高聚物粘结炸药铣削时的边缘崩块形成机理分析

针对高聚物粘结炸药边缘质量的控制与优化问题，采用显微摄像和扫描电子显微镜，研究奥克托今基某高聚物粘结炸药件铣削时边缘崩块的宏观与细观特征及其形成机理。研究结果表明：大切深下铣削边缘产生向工件内部扩展的断裂裂纹而出现边缘崩块，控制切深不大于0.1 mm时可以获得较好的边缘完整性；崩块区域的损伤炸药颗粒以穿晶断裂和孪晶分裂方式破坏，因而完整的炸药颗粒较少；裂纹扩展至自由表面时拉应力与剪应力起主导作用，产生沿晶裂纹、粘接剂开裂以及坑窝等损伤。

Preliminary Research on Formation Mechanisms of Edge Spalling in PBX Milling

In view of controlling and optimizing of edge quality of polymer bounded explosive (PBX), the macroscopic and microscopic characteristics as well as the formation mechanisms of edge spalling formed by milling a HMX-based PBX are studied using microscopic photography and scanning electron microscope (SEM). Research results show that the edge spalling is formed by crack expanding toward inside workpiece at a large cutting depth, while the edge integrity is better when the cutting depth is not larger than 0.1 mm. Intact particles are few in the region of edge spalling due to transcrystalline fracture and twin crystal separation of damaged explosive particles, and the micro-damages, such as crack along crystalline boundary, polymer cracking and void, are mainly due to tensile stress and shear stress when a crack expands toward free-surface.