Pyrolytic Carbine Development Program

Abstract

Refractory pyrolytic carbides were investigated as erosion resistant barriers on the surface of rocket nozzles, specifically for Polaris nozzles with advanced propellants. A mixture of reactant gases composed of a metal halide and a hydrocarbon was developed for coatings of TaC, HfC and NbC on graphite substrates. High density, single phase, impervious carbide coatings were produced which are intimately bonded to their substrate. Special graphites are required with coefficients of thermal expansion compatible with the carbides. Pyrolytic TaCand NbC-coated rocket nozzle inserts resisted erosion. Partial failures, in term of removal of the coatings in the exit cone section of the nozzles, appeared to be caused by thermal stresses or from structural changes in the substrate material. Thermal shock does not appear to be a problem when these coatings are employed. The feasibility of producing full scale rocket nozzles with surface coatings of pyrolytic carbides was also demonstrated.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1961
Accession Number
AD0269658

Tags

Communities of Interest

  • Advanced Electronics
  • Weapons Technologies

DTIC Thesaurus Topics

  • Adhesion
  • Crystal Structure
  • Crystals
  • Erosion Resistance
  • Fabrication
  • Feed Mechanisms
  • Gas Flow
  • Grain Size
  • Materials
  • Materials Processing
  • Measurement
  • Silicon Carbide
  • Standards
  • Thermal Expansion
  • Thermal Shock
  • Thermal Stresses
  • Transition Temperature

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Rocket Propulsion.
  • Surface Engineering/Surface Coating Technology.