Combustion of ammonium dinitramide, Part 1: Burning behavior

The paper presents a detailed analysis of the ammonium dinitramide (ADN) combustion behavior depending on organic and inorganic additives, material of the surrounding shell, and the sample cross-section size. In spite of the fact that ADN is an oxidizer, combustible surroundings have been found to exert practically no effect on the burning rate of ADN pressed strands. In contrast, minor amounts of organic and inorganic admixtures were shown to have a strong effect on ADN burning behavior, extending considerably the pressure limit of sustained combustion to the vacuum area. Within the pressure range of 1-10 MPa, a decrease in the strand cross-section size leads to a decrease in the ADN burning rate, accompanied by a notable burning-rate data scatter. The main reason for the observed combustion behavior is assumed to be a dominant role of exothermic condensed-phase decomposition reactions in burning of ADN. A descriptive mechanism has been proposed to explain the influence of small amounts of different substances added to ADN on its combustion behavior and the low-pressure limit of self-sustained burning.