基于热压耦合护理工艺的熔铸炸药凝固过程数值模拟

Numerical Simulation on Solidification of Melt-cast Explosive Based on Thermocompression Coupling Nursing Process

为了消除熔铸炸药装药过程中形成的药柱内部缺陷,分别以三硝基甲苯(TNT)、二硝基苯甲醚(DNAN)基熔铸炸药为研究对象,模拟分析了不同工艺条件下药料内部缺陷的形成机制及其晶体形态的演变规律,并结合加压补缩、冲头保温和水浴降温等工艺探索凝固护理对熔铸炸药成型质量的影响规律。结果表明,药柱在单一加压护理工艺下由外向内逐层凝固,容易在芯部形成V字型缩孔与缩松区域,且护理温度越高、缺陷区域越大;进一步结合冲头保温与水浴降温等护理工艺不仅可以促进药料的纵向梯度凝固及其内部缺陷的可控迁移,还可以借助水浴环境有效提高其换热效率以缩短凝固周期,从而实现“微缺陷”或“零缺陷”药柱的高效率制备。

To eliminate the internal defects formed in the charge process of melt-cast explosive,the 2,4,6-trinitrotoluene(TNT)and 2,4-dinitroanisole(DNAN)based melt-cast explosives were taken as the research objects,and the forming mechanism of internal defects and the evolution law of crystal morphology in different process conditions were simulated and analyzed.The influence of solidification nursing on the molding quality of melt-cast explosive was also investigated by combining pressure feeding,punch heat preservation and water bath cooling.The results show that the charge is solidified layer by layer from outside to inside under a single pressure nursing process.It is easy to form V-shaped shrinkage cavity and porosity area in the core.Meanwhile,the higher the nursing temperature,the larger the defect area.Further combination of punch heat preservation and water bath cooling can not only promote the longitudinal gradient solidification of slurry and the controllable migration of its internal defects,but also effectively improve its heat exchange efficiency by means of water bath environment to shorten the solidification time.Thus,high efficiency preparation of"micro defect"or"zero defect"charge is realized.