Investigating the Effect of Processing on the Microcrack Creating in the Double-Base Solid Rocket Propellant using Micro-CT Scanning Technique

The burning speed can change in the presence of crack. Cracks cause an increase in the burning level and then increase the pressure in the combustion chamber, which will lead to a decrease in the optimal performance of the engine and sometimes accompanied by an explosion. In this research, samples of double base propellant were prepared by performing mixing operations in Kent, rolling in Walz machine and laboratory press. In order to check the cracks in the engine, sampling was done in the Walz machine at four different points of the engine. Also, the propellant press was performed in a laboratory press in different temperature conditions and with different material movement speeds. After that, crack detection was done by X-ray micro CT scan on engine samples. Results obtained for the press samples showed that the optimal conditions for the preparation of the propellant are the material movement speed of 10 and the temperature of 75 ˚C. Also, the results of Walls samples showed that by increase in homogenization process, the cavity radius in the sample decreases from 25.15 to 16.6 microns and the percentage of voids decreased from 3.5 to 0.5%.