Exploratory Study of Silicide, Aluminide, and Boride Coatings for Nitridation-Oxidation Protection of Chromium Alloys

Abstract

Chromium alloys were coated with silicon, aluminum, and boron by pack cementation. None of these simple coatings provided adequate nitridation-oxidation protection for a chromium +0.17 wt % yttrium alloy substrate as shown by a substantial increase in the ductile-brittle transition temperature after air exposure for 100 hr at 2100 degrees F (1420 K). Iron modified silicides coatings afforded good protection, holding the transition temperature of air exposed specimens to 3500 F (450 K) compared to 200 degrees F (370 K) for recrystallized uncoated specimens. Additional attractive modifying elements included iron-molybdenum, iron-molybdenum-tungsten, iron-molybdenum-tungsten-titanium and vanadium-molybdenum-tungsten-titantum.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1969
Accession Number
ADA380001

Entities

People

  • Joseph R. Stephens
  • William D. Klopp

Organizations

  • National Aeronautics and Space Administration

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Alloys
  • Body Weight
  • Chemistry
  • Chromium Alloys
  • Coatings
  • Ductile Brittle Transition
  • Materials
  • Melting Point
  • Oxidation Resistance
  • Pack Cementation
  • Protective Coatings
  • Solid Solutions
  • Substrates
  • Transition Temperature
  • Transitions
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Materials science

Readers

  • Surface Engineering/Surface Coating Technology.