Experimental research on aluminium–magnesium fuel-rich propellant under high strain rates

Abstract

The aluminium–magnesium fuel-rich propellant is one of the classified propellant used in the solid rocket ramjet. The weapons with the rocket ramjet are under high overload by launching, the mechanical properties of the propellant should be studied under high strain rate. The uniaxial compressive mechanical curves of the aluminium–magnesium fuel-rich propellant under high strain rates have been obtained with the modified split Hopkinson pressure bar in this paper. Four groups of stress–strain curves were obtained at different strain rates of 2600, 3300, 4500 and 5100 s−1. The experimental results show that the mechanical properties of the aluminium–magnesium fuel-rich propellant are rate-dependent, and the Mg–Al fuel-rich propellant has the mechanical properties of viscoelastic material. With the increase of strain rate, the modulus of the aluminium–magnesium fuel-rich propellant obviously increases. The underlying mechanism of the significant rate sensitivity was investigated by adopting the scanning electron microscope from a micro-structure point of view.