B/CuO复合燃料的制备及其对Mg/PTFE富燃料推进剂的影响

为了研究纳米氧化铜(CuO)改性硼(B)对镁/聚四氧乙烯(Mg/PTFE)富燃料推进剂的影响，利用球磨法制备了B/CuO复合燃料，将其添加到Mg/PTFE富燃料推进剂中，利用混合模压成型法制备含有不同比例的复合燃料的推进剂药柱。利用扫描电镜、TG-DSC分别测试了B/CuO复合燃料的微观形貌和热反应性能；利用红外测温仪、X射线衍射、TG-DSC分别测试了推进剂的燃烧速度、燃烧温度、反应产物以及热反应性能。结果表明:复合燃料混合较为均匀，局部有团聚；n(B)∶n(CuO)=32∶3的复合燃料的放热量高于B的放热量，燃烧效率最高，为73.1%，点火温度比B低66 ℃。含此复合燃料的推进剂的燃烧速度和质量燃烧速度均高于Mg/PTFE,分别提高了25.6%和3.1%，平均燃烧温度降低了16 ℃，最高燃烧温度则提高了6 ℃，但是相对于含B的Mg/PTFE推进剂，含此复合燃料的推进剂的燃烧速度和质量燃烧速度分别下降2.91%和19.51%，平均燃烧温度下降了94 ℃和121 ℃；复合燃料推进剂一次燃烧的凝聚相产物主要有MgF₂、MgO、C、Cu以及Mg₃F₃（BO₃）；一次燃烧反应过程主要是PTFE的分解以及F₂和Mg的反应，二次燃烧反应过程则主要为C、Mg以及复合燃料的氧化。

Preparation of B/Cuo Composite Fuel and Its Influence on Mg/PTFE Fuel-rich Propellant

In order to study the effect of boron modified by nano-CuO on Mg/PTFE fuel-rich propellant, B/CuO composite fuel was prepared by ball-milling method and put into Mg/PTFE fuel-rich propellant as additives, and then three kinds of Mg/PTFE fuel-rich propellants with different types of B/CuO composite fuel were prepared by mixing and molding technology. Microstructure and thermal reactivity property of B/CuO composite fuel were tested by SEM and TG-DSC respectively. Burning rate, burning temperature, reaction product and thermal reactivity performances were tested by thermal infrared imager, X-ray diffraction and TG-DSC. Results show that the fuel is mixed relatively uniform, but aggregates partially. Heat generation of B/CuO composite fuel, in which n(B)∶n(CuO) is 32∶3, is higher than boron powder, its combustion efficiency (73.1%) is the highest, and ignition temperature is 66 ℃ lower than that of boron powder. Compared with Mg/PTFE propellant, combustion velocity and mass combustion velocity of Mg/PTFE fuel-rich propellant containing this composite fuel increase by 25.6% and 3.1% respectively, average combustion temperature decreases by 16 ℃, and the highest combustion temperature improves by 6℃. While compared with Mg/PTFE propellant containing B, combustion velocity and mass combustion velocity of Mg/PTFE fuel-rich propellant containing this composite fuel decrease by 2.91% and 19.51% respectively, and average combustion temperature and the highest combustion temperature decrease by 94 ℃ and 121℃. The primary combustion products of propellant containing composite fuel powder were MgF₂, MgO, C, Cu and Mg₃F₃(BO₃).The primary combustion reactions are PTFE decomposition and reaction between F₂ and Mg. While the secondary combustion reactions involve oxidations of C, Mg, and composite fuel.