Oxidation Resistance of CVD (Chemical Vapor Deposition) Coatings

Abstract

Chemical vapor deposition (CVD) of iridium, platinum, rhodium, zirconia oxide, and hafnia oxide was investigated for the purpose of protecting Re, molybdenum, Ni, Nb, copper and carbon composites from oxidation at temperatures from 1000 to 2000 C. Iridium has proved easiest to deposit. Earlier difficulties with codeposition of carbonaceous residues were overcome, and dense, adherent, coatings which stop oxidation of the substrate are reliably produced. The iridium deposition process developed here was applied in the fabrication of several rhenium thrusters. Some of these have been test fired by Aerojet Techsystems using MMH/NTO propellant. One chamber has completed over 8 hours of operation including over 3600 starts and 4 hours burn time between 2150 and 2200 C at a mixture ratio of 1.65. No measurable change in throat diameter was observed and the mass loss was only 0.9 g or 1.4%. Keywords: Rhenium, Hafnia, Zirconia, Oxidation resistant coatings.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1987
Accession Number
ADA178337

Entities

People

  • John T. Harding
  • R. B. Kaplan
  • R. H. Tuffias
  • Vince Fry

Tags

DTIC Thesaurus Topics

  • Alloys
  • Chemical Vapor Deposition
  • Chemistry
  • Composite Materials
  • Contracts
  • Elements
  • Graphitic Materials
  • High Temperature
  • Materials
  • Materials Laboratories
  • Materials Science
  • Organic Compounds
  • Oxidation Resistance
  • Refractory Metals
  • Rocket Propulsion
  • Rockets
  • Space Systems

Fields of Study

  • Materials science

Readers

  • Rocket Propulsion.
  • Surface Engineering/Surface Coating Technology.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster