Catalytic Effect of Added Fe2O3 Amount on Thermal Decomposition Behaviors and Burning Characteristics of Ammonium Nitrate/Ammonium Perchlorate Propellants

Ammonium nitrate (AN) and ammonium perchlorate (AP) are investigated as propellants for their thermal decomposition behaviors and burning characteristics. The performance effects of AP particle size, AP content in the oxidizer (xi), and a catalytic amount of Fe2O3 on the propellants are evaluated. A dependency exists between the thermal decomposition behaviors of the propellants and both AP particle size and xi. Addition of Fe2O3 further affected the thermal decomposition behaviors of the propellants; these behaviors are not dependent on the added amount. Furthermore, the burning characteristics are dependent on the AP size, xi, and the amount of Fe2O3 added. The low-pressure ignitability of the propellants containing 2% Fe2O3 with xi = 0.2 and 0.4 is inferior to the propellant with xi = 0 (no AP) and the propellants containing 4% Fe2O3 with xi = 0.2 and 0.4. An increase in 4% Fe2O3 caused a positive catalytic effect, causing an equal or higher burning rate of the propellants than that of 2% Fe2O3, except in the case of AN/AP propellants with coarse AP at xi = 0.4 and 0.6 above 4 MPa.