BALLISTICAL AND CHEMICAL STABILITY OF ROLLED BALL PROPELLANTS

摘要

This paper presents in summary the work of a Belgian-French-German cooperation programme on the chemical and ballistical stability of a ball propellant for the 5.56 · 45 mm ammunition. The programme comprises thermoanalytical, analytical, ballistical and spectroscopical techniques applied on imaged and aged samples of the propellant K 5810. The propellant K 5810 is chemically stable. This fact is proven by microcalorimetry; the maximum heat flow does not reach the limit values of STANAG 4582. Also the stabilizer content after ageing times which are comparable to a 10 years storage at 25 ℃ is much higher than the limit values given in AOP-48, Ed. 2. The ageing mechanism is strongly dependent on the loading density of the ampoules and the atmosphere above the sample which underlines the big effect oxygen has on the ageing of nitrocellulose based propellants. The slight energy loss during the ageing periods used here does not affect the ballistic behaviour significantly. In contrast to the 9 mm ammunition tested before there seems to be no incompatibility between the propellant and the Sintox primer because the propellant K 5810 does not contain isopropanol in contrast to the K 6210 propellant in the 9 mm ammunition. The ballistic life time is limited by the migration of the deterrent. This migration leads to an increased burning rate and thus to an increased pressure in the early phase of the burning reaction. As not all samples are available at the moment a final value for the activation energy of the migration of the DBP can not be given. First estimations lead to a value slightly above the activation energy of the nitrate ester decomposition.