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8162401 
Journal Article 
Effect of magnalium (Mg-Al alloy) on combustion characteristics of ammonium nitrate-based solid propellant 
Murata, H; Azuma, Y; Tohara, T; Simoda, M; Yamaya, T; Hori, K; Saito, T 
2000 
61 
2 
58-66 
Japanese 
Recently, many studies have been conducted on `chlorine-free' ammonium nitrate (AN) which might replace ammonium perchlorate (AP) in solid composite propellants. However, it is necessary to improve combustion characteristics of AN-based composite propellants, such as ignitability and burning rate. Therefore, the present study aims at improving combustion characteristics of AN-based composite propellants with magnalium (Mg-Al alloy) as metal fuel. Magnalium decreased decomposition temperature of AN by 40 °C and transforms the form of AN thermal decomposition into two-stage reaction. At the first stage only AN decomposes and at the second stage melted AN and/or oxidant gases issued from AN cause condensed reaction or heterogeneous reaction with solid magnalium. The oxide of magnalium is produced as a residue. Magnalium-containing AN-based propellants are superior to Al-containing AN-based ones in the self-sustaining burning at low pressures and burning rates. The burning rate of AN-based propellants increases with content of magnalium. The propellant with the formulation of AN/HTPB/Mg-Al = 48/32/20 (wt%) showed the burning rate of 3.58 mm/s at 5 MPa and the pressure exponent of 0.3.