Characterization of aluminized RDX for chemical propulsion

Abstract

The chemical response of energetic materials is analyzed in terms of 1) the thermal decomposition under the thermal stimulus and 2) the reactive flow upon the mechanical impact, both of which give rise to an exothermic thermal runaway or an explosion. The present study aims at building a set of chemical kinetics that can precisely model both thermal and impact initiation of a heavily aluminized cyclotrimethylene-trinitramine (RDX) which contains 35% of aluminum. For a thermal decomposition model, the differential scanning calorimetry (DSC) measurement is used together with the Friedman isoconversional method for defining the frequency factor and activation energy in the form of Arrhenius rate law that are extracted from the evolution of product mass fraction. As for modelling the impact response, a series of unconfined rate stick data are used to construct the size effect curve which represents the relationship between detonation velocity and inverse radius of the sample. For validation of the modeled results, a cook-off test and a pressure chamber test are used to compare the predicted chemical response of the aluminized RDX that is either thermally or mechanically loaded.

Study on the Aging Mechanism of Boron Potassium Nitrate (BKNO3) for Sustainable Efficiency in Pyrotechnic Mechanical Devices

“…The reaction progress α( t ) of a DSC profile is expressed aswhere S ( t ) is a DSC signal as a function of time with respect to the temperature and B ( t ) is the baseline determining the amount of heat flow. The reaction progress at the temperature related to time (heating rate) is calculated using the summation of the released energy divided by the total released energy 40 …”

“…To investigate the reaction rate as a function of the temperature by varying the heating rate, we converted DSC data using AKTS. The relevant equation is expressed below 40 .As shown in Fig. 3c and Table 1, the reaction rate increases when the heating rate is increased.…”