Ignition and Combustion of Composite Solid Propellants Based on a Double Oxidizer and Boron-Based Additives

The use of boron-based powder materials in solid propellant compositions is an effective method for increasing the energy characteristics in the combustion chamber due to increasing the released energy through the combustion of boron particles. In this study, powders of amorphous boron and aluminum borides, obtained by the method of self-propagating high-temperature synthesis—the SHS method, which were added to the composite solid propellant composition based on a double oxidizer and an energy fuel binder, are studied. The paper presents the characteristics of thermal decomposition, ignition, and combustion for solid propellant samples. The tested samples are ignited using a continuous CO2 laser in the air in the heat flux density range of 90 to 200 W/cm2. The combustion of propellant samples is carried out in a manometric bomb in a nitrogen atmosphere at pressures ranging from 0.5 to 7.0 MPa. It is shown that the use of amorphous boron and aluminum boride powders in the solid propellant composition reduce the ignition delay time and increase the burning rate of the samples compared to the aluminum-based propellant composition, due to the increase in temperature near the surface of the reaction layer of the sample and the specific heat release during the oxidation and burning of boron.