Study on the forming quality of double-base gun propellants based on extrusion 3D printing technology

Abstract

In order to improve the forming quality of 3D printed gun propellants, rosette-shaped 19-perf double-base gun propellants with different geometric dimensions (inner diameter and web thickness) were printed by extrusion 3D printing technology based on conventional double-base propellant formulations. The printed gun propellants were characterized in terms of surface structure, inner diameter and web thickness dimensional uniformity, and density. The effects of geometrical dimensions (inner diameter and web thickness) and printing process parameters (line width and flow compensation) on the forming quality of gun propellant were studied. The results showed that printed rosette-shaped 19-perf double-base gun propellants have a good surface structure with a clear outer profile and inner diameter from 1.5 mm to 3.0 mm. When the printing process parameters were the same, the larger the geometry, the higher the dimensional uniformity of the printed gun propellant. When the printing model was the same, the decrease in printing line width and the increase of printing flow compensation in the printing process parameters had the same effect on the dimensional uniformity of the printed gun propellant. The rosette-shaped 19-perf gun propellant with a model inner diameter and web thickness of 1.5 mm had the best dimensional uniformity at the printed line width and flux compensation of 0.45 mm and 1.0, respectively, with relative standard deviations of 2.699%, 1.986%, and 2.458% for inner diameter, inner and outer web thickness, respectively. The density of the printed propellant ranged from 1.565 to 1.606 g·cm−3. This study has a guiding significance for the application of extrusion 3D printing technology in the field of gun propellant.