炸药高压燃烧实验技术及其燃速-压力特性研究

The burn rate-pressure characteristics of explosive is the intrinsic factor of ammunition safety, which reflects the potential tendency of enhancing the reaction violence by convective burning mechanism. It is great meaningful to understand the dominant factors and process mechanism of explosive combustion behavior for source control and risk prediction of ammunition accidents. In this work, focusing on the burn rate as a function of pressure, the experimental technology of explosive combustion at high pressure will be studied to develop experimental method of burn pressure-burn consumption in close bomb and burn rate test method, which will realize multi-range and high precision characterization of explosive burn rate-pressure characteristic. Furthermore, the effects of pressurization rate on the burn rate-pressure characteristic will be investigated under ambient and high temperatures to obtain the dependence relation between burn rate and pressure. The key parameters such as burn rate constant and pressure index will be compared to grasp the main controlling external factor. Meanwhile, the combustion specific surface area will be analyzed to acquire the relation between combustion specific surface area and pressure, which will contribute to revealing the combustion surface structure evolution process. This work effort could not only establish a precise characterization method for combustion behavior of explosive at high pressure, but also provide the basis and technical support for formulation design and regulation of explosive in safety, which will help to present valuable reference for the source control of explosive formulation selection and prediction of explosive reaction violence.

炸药燃速-压力特性是弹药安全性的关键内因，反映了反应烈度经对流燃烧机制提升的潜在倾向，深入认识和理解炸药燃烧特性主控因素和过程机理对弹药事故源头控制和风险预测具有重大意义。本项目拟围绕炸药燃速与压力关系，开展高压燃烧实验技术研究，发展高压密闭空腔燃烧压力-燃烧耗量实验方法和燃烧速率测试方法，实现炸药燃速-压力特性多量程、高精度表征；进一步以高聚物粘结炸药（PBX）为对象，研究常温和温度载荷下增压率对炸药燃速-压力特性的影响，获得炸药燃速与压力依赖关系，对比炸药燃烧速率常数和压力指数等关键参数，掌握炸药燃速-压力特性主控外因；同时分析炸药燃烧比表面积变化，获得炸药燃烧比表面积与压力关系，阐明炸药基体燃烧表面结构演化过程。研究结果将建立一种高压燃烧特性精密表征方法，为炸药配方安全性设计调控提供基础和技术支撑，有助于给炸药配方选择源头控制、炸药反应烈度预测提供有价值的依据。

炸药燃速-压力特性是弹药安全性的关键内因，反映了反应烈度经对流燃烧机制提升的潜在倾向，深入认识和理解炸药燃烧特性主控因素和过程机理对弹药事故源头控制和风险预测具有重大意义。本项目以武器安全性需求为背景，针对炸药高烈度反应过程的燃烧阶段，首先开展了炸药高压燃烧实验技术研究，突破了高压预加压、超高压密封等关键技术，发展了密闭空腔燃烧压力-炸药耗量法和炸药燃烧速度原位测试方法，建立了炸药高压燃速-压力关系实验系统，实现了最大预加压300MPa、最高工作压力1GPa的能力，达到了国外同行（LLNL）该方法同等的技术水平，已应用于炸药燃速-压力关系研究。其次，以高聚物粘结炸药（PBX）为对象，通过实验获得了HMX基、TATB基不同PBX炸药在不同压力下的燃速数据，对比分析了不同配方炸药燃速-压力特性的差异，对于HMX基PBX炸药，HMX含量及粘结剂属性对炸药的燃速-压力特性影响较大；但对于TATB基PBX炸药，TATB含量及粘结剂属性对炸药的燃速-压力特性影响较小，认识了典型主炸药燃烧性能的差异和主要影响因素，明确了不同配方炸药反应烈度增长的潜在倾向性，可为后续主炸药配方安全性筛选、调控及设计提供重要支撑。最后，发展了炸药燃烧过程燃烧比表面积计算模型，认识不同配方炸药燃烧比表面积与压力的关系，为炸药反应烈度评估及预测提供新的依据，结果表明，对于HMX基PBX炸药，压装炸药在压力100MPa~180MPa压力范围内其燃烧表面积均出现1~2数量级的增加，而浇注炸药在400 MPa压力范围内燃烧比表面积未出现剧增，炸药物理化学属性及炸药成型工艺是影响炸药基体燃烧表面结构演化的重要因素；对于TATB基PBX炸药，在几百MPa压力范围内，炸药燃烧比表面积均在1附近发生波动，其燃烧机制未发生改变，一直处于热传导燃烧，其安全性能较好。本项目建立了一种精密高压燃烧特性表征方法，为炸药配方安全性设计调控提供基础和技术支撑，有助于给炸药配方选择源头控制、炸药反应烈度预测提供有价值的依据。