The Study On Module Ammonium Nitrate Gun Propellant

To reduce the undesirable phenomenon of barrel weapons such as muzzle smoke and muzzle flame, to solve the problem of moisture absorption of ammonium nitrate(AN) gun propellant, AN gun propellant particles were compacted and coated with two hydrophobic polymer materials and module AN gun propellant was obtained. Through theoretical calculation and experimental analysis, effects of AN content, proportion of module, aspect ratio of base-propellant particles, coating material on combustion and hygroscopic of module AN gun propellant were studied, the gas composition and combustion performance of propellant mixed by module AN gun propellant and gun propellant-6/7 were studied. The study lay the foundation of the application of module AN gun propellant.The oxygen balance of the propellant was calculated, energy parameters of different AN content and different coating material module gun propellant were calculated by the inner energy method, the gas composition of mixed propellant was calculated by the minimum free energy method. The results show that: when the AN content is increased, oxygen balance of the module propellant and mixed propellant is increased, combustible gases in gas products of mixed propellant are decreased. In the formula range, with increasing of AN content, propellant force of the module propellant is decreased, explosion temperature and explosion heat are increased firstly and then are decreased.Hygroscopicity of the coated module propellant was tested though dryer balance method. The results show that: with proportion of module propellant increasing, AN content is decreased and aspect ratio of base-propellant particles is increased, the hygroscopicity of module propellant is decreased. The anti-hygroscopic function of A coating material is stronger than B, hygroscopicity of the module propellant with A+B coating material is far less than single-base gun propellant.Combustion performance of the module propellant and mixed propellant was studied by closed bomb text. The results show that: with proportion increasing, gas release rate of the module propellant and mixed propellant is decreased firstly and then is increased. With AN content increasing, the maximum pressure point of the module propellant and mixed propellant is advanced, dP/dt、u、L、Γ of the module propellant are increased, dP/dt、u、L、Γ of mixed propellant are increased in early stage, decrease in late stage; with aspect ratio of base-propellant particles increasing, the maximum pressure point of the module propellant and mixed propellant are put off, dP/dt、u、L、Γ of the module propellant are decreased.Gas composition of mixed propellant was analyzed though closed bomb-gas chromatographic method. The results show that: with AN content increasing, combustible gases in gas products are decreased, combustible gases of the module propellant with B material coated are less than module propellant with A material coated.