Exploring the Influence of Colloidal Graphite on Granule Casting Modified Double-Base Propellant Granules

Two kinds of granules were coated and modified by colloidal graphite through mechanical method. The microstructure of colloidal graphite was observed by SEM and TEM as well as the granules and the modified granules. On the basis of the characterization of the microstructure of granules, changes of the flowability of the granules and the modified granules were tested via Carr index method and PFT power flow tester. At the same time, the mechanical sensitivity, electrostatic spark sensitivity, loading density, screen loading density of the four kinds of granules and the density of the propellants manufactured by the granules were tested. The results indicated that the microstructure of the colloidal graphite was irregular scaly which size was about 5 μm. After the granules were coated and modified by colloidal graphite, the mechanical sensitivity and electrostatic spark sensitivity was improved in some extent, while the flowability was improved greatly, therefore the loading density and screen loading density was increased, as a result, the density of the propellants were increased as well and more closely to their theoretical density respectively.