Accession Number : ADA285792

Title :   Morphology of Extinguished Monolithic JA2 Grains Fired in a 30-MM Solid Propellant Electrothermal-Chemical (SPETC) Gun.

Descriptive Note : Final rept. Sep 93-Jan 94,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Lieb, Robert J. ; Gillich, Christopher J.

PDF Url : ADA285792

Report Date : NOV 1994

Pagination or Media Count : 33

Abstract : Monolithic grains of JA2 were fired in a 30-mm solid propellant electrothermal-chemical (SPETC) gun and were recovered after self-extinguishing because of depressurization. A morphological investigation was performed on these grains to gain insight into the interaction between the plasma and the propellant. Scanning electron microscopy (SEM) was used to characterize the morphology of the combustion surface and bulk of the propellant. Results show that the propellant burning surface was pitted and showed evidence of both brittle fracture and plastic flow. These features were the results of rapid pressurization within the single perforated grain caused by the plasma injection and the subsequent burning. Regions within the propellant showed evidence of augmented mass generation when compared with conventional propellant combustion. Mechanisms causing this accelerated burning are conjectured; they included erosive burning, fracture-generated tunneling, and in-depth buming. Micrographs are presented to support these findings and proposals are made to exploit these enhanced burning processes. SPETC, ETC, JA2, Gun propellants, Morphology, Extinguished.

Descriptors :   *CHEMICALS, *COMBUSTION, *GUNS, *MORPHOLOGY, *SOLID PROPELLANTS, DEPTH, ELECTRON MICROSCOPY, EROSIVE BURNING, EXTINGUISHING, GAIN, GUN PROPELLANTS, INJECTION, INTERACTIONS, MASS, MICROSCOPY, PLASTIC FLOW, PRESSURIZATION, SCANNING, SURFACES, TUNNELING, FIRING TESTS(ORDNANCE), PLASMA DEVICES, PITTING, BRITTLENESS, FRACTURE(MECHANICS), RESIDUALS, IGNITION, PROPELLANT GRAINS.

Subject Categories : Guns
      Electricity and Magnetism
      Thermodynamics
      Rocket Propellants

Distribution Statement : APPROVED FOR PUBLIC RELEASE