Dry-mixing of sub-micron B and BaCrO ₄ particles for use in a time delay composition

This paper is a study of a novel dry mixing technique called Magnetic Assisted Impaction Mixing (MAIM). This study will investigate the MAIM performance through mixing two powder components and determining the mechanism's mixing capability and how it impacts the mixed product's performance. The powder components used are Boron (B) and Barium Chromate (BaCrO ₄), a time delay composition also known as T-10. This mixing method produced mixtures with a narrow particle size distribution range (0.1 - 6 μm). The corresponding Particle Size Distribution (PSD) results indicate that MAIM has a significant effect in breaking down the agglomerates of the components such that the final mixture size had a mean particle size of 1.5 μm. Imaging analysis of the MAIM mixture visibly showed that this method produced mixtures with a noticeable level of particle size uniformity, both on the micron and submicron level, as well as having improved distribution of boron throughout the mixture. The performance, burn rate, was tested and was well within the performance requirements. The results indicates that the MAIM quite easily achieves a uniform mixture with a good level of distribution between the two mixed constituents. A comparison between the MAIM product and another mixing product using the same mixing components, showed that the MAIM product clearly has a better particle size distribution and this is further noted in the increased distribution of B.