New Classes of Ceramic Materials for Thermal Barrier Coating Applications.

Abstract

This project investigated the feasibility of using new ceramic materials/concepts for use in thermal barrier coating applications. In one approach, the effect of solid solution on thermal conductivity of refractory spinels (magnesium aluminate-based) was evaluated. Plasma spray process was used to fabricate free-standing discs of spinels with various amounts of cobalt. Preliminary results show that a 2% doping of cobalt in MgA12O4 was effective in lowering thermal conductivity. In another approach, the use of layered oxides for TBC applications was explored. Hot pressed samples of potassium calcium niobate (KCN) and another proprietary layered oxide were used to determine the k-T behavior. While both compositions showed significantly low k values (similar to YSZ), KCN decomposed above 1200 degrees C, whereas the second layered oxide was stable at least up to 1400 degrees C. These preliminary results warrant further investigation of such new concepts/materials.

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Document Details

Document Type
Technical Report
Publication Date
Nov 18, 1999
Accession Number
ADA371309

Entities

People

  • Sankar Sambasivan

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms

DTIC Thesaurus Topics

  • Barrier Coatings
  • Ceramic Materials
  • Chemical Properties
  • Chemistry
  • Conductivity
  • Corrosion Resistance
  • Heat Transfer
  • Heat Treatment
  • High Temperature
  • Materials
  • Mechanical Properties
  • Metals
  • Physical Properties
  • Solid Solutions
  • Thermal Conductivity
  • Thermal Diffusivity
  • Thermal Expansion

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.
  • Surface Engineering/Surface Coating Technology.