Contact surface area of a pyrotechnical granular material

Abstract

The pyrotechnic composition RS-41, a mixture of 49wt% KCLO4, 49wt% Al/Mg and 2wt% Calcium Resinat, is an important ingredient in the Multipurpose (MP) ammunition. RS-41 is placed in front of the projectile and ignites due to the impulse transfer on impact. A pyrotechnical combustion starts and spreads backward in the projectile and towards the explosive. This gives a delay, which is important for the fragmentation effect of the warhead. In this report we have analysed the contact surface area of the particles in RS-41 as a function of the density by looking at the roughness of the bulk surface of compressed pellets. We found that the contact area increased with the pressure. The contact area is compared with old measurements based on the luminosity of the same surface.