Refractory Chamber Materials for N2O4/Amine Propellants
Technical rept. Oct 1970-Feb 1973
MARQUARDT CO VAN NUYS CA
Pagination or Media Count:
Oxidation resistant materials suitable for passively cooled thrust chambers for N2O4 Amine propellants were evaluated by nozzle test firings at 400 psia to 600 psia. Thermal stress analysis was performed to establish designs capable of performing long duration, multiple restart duty cycles. A nozzle insert made of edge oriented washers of zirconium pyrocarbide and hafnium pyrocarbide experienced high erosion rates comparable to pyrolytic graphite washers. A pyrolytic graphite coated Carbitex nozzle experienced low erosion rates, about 1 milsec. The best erosion resistance was demonstrated by a zirconium diboridc insert made of Material VIII 18,10 from Man Labs, Inc. This insert, in the form of two segments, was designed to resist thermal shock by free thermal expansion and by heat flux reduction through a preoxidized coating. This nozzle concept allows the use of materials formerly prohibited from rocket nozzle applications because of thermal stress sensitivity.
- Ceramics, Refractories and Glass
- Rocket Engines