Catalytic effect of ferric oxide on burning characteristics of propellants using ammonium perchlorate with varied particle properties

Abstract

Fe2O3 is an excellent burning catalyst for ammonium perchlorate (AP)-based propellants. There is no sufficient experimental data yet on the burning characteristics of propellants supplemented with Fe2O3. In this study, the burning characteristics of propellants supplemented with less than 4% Fe2O3 were investigated using 69–80% coarse, fine, or fine porous AP. The catalytic effect on the burning rate increased with increasing pressure for the propellant using coarse AP, whereas an opposite effect was observed for the propellant using the fine AP. The catalytic effect for the propellant using porous AP was independent of the pressure. The optimum amount of Fe2O3 for increasing the burning rate was 1%, which was independent of the AP particle properties, AP content, and pressure. The dependence of the catalytic effect on the AP content was affected by the AP particle properties below 72% AP, while it was hardly affected above 74%. The pressure exponent was dependent on the AP particle properties, but the exponents of the propellants with Fe2O3 were not affected by the amount of Fe2O3 added. A qualitative analysis based on the combustion wave structure was conducted to elucidate the catalytic mechanism.