El+ - a new, nitro-glycerine free and sensitiveness reduced propellant for medium calibre and mortar applications

摘要

During the last decade, El~(~R) technology (El~(~R) = Extruded-Impregnated) became well established in the field of medium calibre and mortar propulsion. In particular for kinetic energy ammunition, El~(~R) propellants allow a significant gain in interior ballistic performance if compared to conventional products. In the mortar application, interior ballistic dispersion is reduced and service life is significantly increased (the latter due to a reduction of the diffusion processes taking place between propellant and combustible containers). As a consequence, El~(~R) propellants successfully displaced conventional propellants in many medium calibre and mortar ammunition systems. Basing on El~(~R) technology, a new, nitro-glycerine free variant, called El+, was developed recently. Main target of this propellant generation was to get a further increase in system compatibility. Results are presented showing that this new technology allows to retain the advantageous features well known from "standard" El~(~R) propellants, such as high performance and adjustable temperature behaviour, whilst flame temperature (and thereby the potential for gun barrel erosion) as well as sensitivity are significantly reduced. In particular, slow cook-off behaviour and chemical stability are considerably improved. Plasticizer concentration profiles show that no significant diffusion takes place during propellant ageing. As a consequence, excellent ballistic stability is achieved.