含硼推进剂一次燃烧固相产物氧化反应特性

Oxidation Characteristics of Solid Phase Primary Combustion Products of Boron-Based Propellants

关键词:  硼基推进剂  二次燃烧  含氧添加剂  热氧化  激光点火燃烧

Key words:  Boron-based propellant  Secondary combustion  Oxygenated additives  Thermal oxidation  Laser ignition and combustion

摘要:

对硼基推进剂一次燃烧固相产物进行研究，是获得硼基推进剂二次燃烧氧化特性的重要手段。为比较在硼基推进剂初始配方中添加KClO4和CL-20两种含氧添加剂对其二次燃烧氧化特性的影响，通过场发射扫描电镜、常压热分析系统和自主研发的激光点火试验系统对硼基推进剂一次燃烧固相产物样品进行了试验研究。结果表明，样品的热氧化过程主要包含三次失重过程和一次增重过程。先后经历了H3BO3分解析出的水分蒸发、NH4Cl分解、C和BmCn氧化、B的氧化过程。在硼基推进剂初始配方中使用CL-20代替KClO4，可使样品的放热量由7.62kJ/g提升到8.33kJ/g。样品的激光点火燃烧过程中可以观察到B，C两种元素的特征光谱。添加了KClO4的样品中还能观察到KCl的特征光谱。在硼基推进剂中添加CL-20比添加KClO4更有利于其一次燃烧固相产物的点火和自持燃烧，可使其二次燃烧的平均燃烧温度由1512°C提升到1633°C。

Abstract:

Study on primary combustion products is important to obtain the secondary combustion characteristics of the boron-based propellant. To compare the secondary combustion characteristics of boron-based propellants with different oxidizers (KClO4 and CL-20)，two primary combustion products were studied using a field emission scanning electron microscope，a thermogravimetric balance，and a laser ignition experimental system. Results indicate that the thermal oxidation process of the samples mainly contain three mass loss stages and one mass gain stage. The water evaporation caused by decomposition and precipitation of H3BO3，NH4Cl decomposition，C oxidation，BmCn oxidation，and B oxidation processes taken place successively. The heat release of the sample can be enhanced from 7620J/g to 8333 J/g by adding CL-20 instead of KClO4 in the original formula of boron-based propellant. Characteristic spectra of B and C elements were observed in laser ignition and combustion processes of both samples. The characteristic spectrum of KCl was also observed in combustion process of the sample with KClO4. CL-20 has better influence on the ignition and combustion of the primary combustion products than KClO4，and can increase the average combustion temperature from 1512 °C to 1633 °C.