Study on AP and PVDF for Improving the Ignition and Combustion Performance of Boron Particles

Boron (B) particles offer the advantage of high energy density for ramjet applications but suffer from challenges including difficult ignition, low combustion efficiency, and agglomeration. This study employed ammonium perchlorate (AP), a common propellant oxidizer, and polyvinylidene fluoride (PVDF), a fluorine-containing compound, to improve the ignition and combustion characteristics of boron particles. Two types of samples were prepared: boron particles coated with AP, and boron particles mechanically mixed with PVDF. Thermal analysis indicated that both AP coating and PVDF addition facilitated the thermal decomposition of boron, significantly lowering its decomposition temperature. Laser ignition experiments under two different atmospheres revealed that AP coating consistently intensified boron combustion. The ignition delay time was reduced and the combustion temperature was increased. However, the effectiveness of PVDF addition may be influenced by the ambient oxygen concentration. Consequently, both AP coating and PVDF addition are advantageous for enhancing boron combustion.