Refractory Chamber Materials for N2O4/Amine Propellants

Abstract

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 mil/sec. 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.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1973
Accession Number
AD0762531

Entities

People

  • John G. Campbell

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Combustion Chambers
  • Composite Materials
  • Graphitic Materials
  • Heat Transfer
  • Materials
  • Oxidation
  • Oxidation Resistance
  • Physical Properties
  • Resistance
  • Silicon Carbide
  • Stress Analysis
  • Stresses
  • Temperature Gradients
  • Thermal Expansion
  • Thermal Shock
  • Thrust Chambers

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Rocket Propulsion.