FEASIBILITY DEMONSTRATION OF PYROLYTIC GRAPHITE COATED NOZZLES
Final rept. 2 Feb 1964-4 Mar 1965
ATLANTIC RESEARCH CORP ALEXANDRIA VA
Pagination or Media Count:
Pyrolytic graphite coatings have been found to be highly erosion resistant under severe rocket nozzle conditions. The objective of this program was to demonstrate the feasibility of such coatings for nozzles up to 2.3-inch diameter in firings at 700 psi with a 6550 F propellant. This objective was accomplished. Stress and thermal analyses were carried out in support of the design, fabrication, and motor testing of nozzles of both 1.1-inch and 2.3-inch diameter. Thermal analysis indicated the potential of pyrolytic graphite coatings for lightweight nozzle designs. The results of the stress analyses for coated composites were correlated with experimental evidence of delamination cracking in the coatings. Critical stress levels were identified for both radial tension in the coating and axial tension in the substrate. The deposition process was improved to produce crack-free coatings 50-mil-thick on conventional graphite substrates and 100-mil thick on a fabrous graphite substrate.
- Rocket Engines