Fabrication and investigation of 3D-printed gun propellants

Gun propellant is the energy source of barrel weapons. A 3D printed gun propellant based on "Stereolithography (SLA)" was developed to overcome the limitation of traditional extrusion technologies. A demonstration formulation composed of 50 wt% 1,3,5-Trinitro-1,3,5-triazinane (RDX), 25 wt% epoxy acrylate, 12.5 wt% N-n-butyl-N(2-nitroxyethyl) nitramine (Bu-NENA), 12.5 wt% reactive diluent and additives were fabricated. The 3D-printed propellants were characterized in terms of inner structure, mechanical strength and combustion behavior. Finally, a ballistic assessment of multi-perforated disk (MPD) propellant was carried out using a 30 mm test gun. The results showed that no signs of porosity or defects existed in the propellant printed by the SLA technique. The compression strength and tensile strength were 21.6 MPa and 7.3 MPa, respectively. The 3D-printed propellant exhibited a relatively low linear burn rate and a high pressure exponent value of 1.46. In the gun test, a muzzle velocity of 420 m/s was achieved without crushing the MPD. (C) 2020 The Authors. Published by Elsevier Ltd.