Accession Number : AD0273774

Title :   IMPROVEMENT OF THE USEFULNESS OF PYROLYTIC GRAPHITE IN ROCKET MOTOR APPLICATIONS

Corporate Author : ATLANTIC RESEARCH CORP ALEXANDRIA VA

Personal Author(s) : BATCHELOR, J.D. ; FORD, E.F. ; MCCORMICK, S.W. ; OLCOTT, E.L. ; WHITE, R.K.

PDF Url : AD0273774

Report Date : 20 MAR 1962

Pagination or Media Count : 30

Abstract : Tests of coated nozzles were made to measure the inherent serviceability of pyrolytic graphite under severe conditions using an advanced propellant of 6500 F flame temperature. Deposition runs, in which pyrolytic graphite was formed at a low temperature (1340 C) on tubular substrates of three different grades, showed significant differences in the microstructure of the coating. The deposit on a relatively non-graphitic substrate had a finer microstructure than that on the standard graphite substrate. The coating on a high-purity, coarse-grained graphite had a coarser structure. Steam pretreatment of the substrate produced an increase in the cone size in pyrolytic graphite which was probably caused by increased activity of local sites on the substrate surface. Pyrolytic graphite nozzles were tested in three rocket motor firings to define the effect of motor pressure on the erosion rate of the standard (2000 C) coating. A fourth motor test indicated that a lower temperature coating (1700 C) was not serviceable with the 6500 F propellant.

Descriptors :   *ROCKET NOZZLES, *GRAPHITE, PHYSICAL PROPERTIES, PROCESSING, REFRACTORY COATINGS, COMBUSTION, EROSION, COMBUSTION DEPOSITS, SOLID ROCKET PROPELLANTS, MANUFACTURING, MICROSTRUCTURE, COATINGS

Subject Categories : Rockets

Distribution Statement : APPROVED FOR PUBLIC RELEASE