Development of Directionally Solidified Eutectic Ceramic Matrix-Metal Composites

Abstract

The third and final year of effort to identify and develop directionally solidified ceramic matrix-metal eutectic composites for use uncoated at temperatures exceeding 1315 C (2400 F) in aircraft gas turbines is reported. The primary approach was to identify oxide-metal systems in which the metal whisker phase would form a self-protective oxide coating on exposure to air at elevated temperatures. Many different oxide-metal combinations were examined by melting prefired slugs contained tungsten wire baskets. The specimens were melted by radiation from a carbon susceptor inductively heated in argon. A wide range of cubic mixed oxides in combination with high-melting pure metal candidates were examined. A number of compositions were found which solidified as regular oxide-metal eutectics but difficulties with container reactivities and with the volatility of certain components prevented the fabrication of ingot samples suitable for further evaluation. Although the possibility remains that suitable eutectic systems may exist, the general conclusion from this work is that chances for the successful development of an oxide-metal eutectic system for structural use uncoated in air at elevated temperatures should now be considerably reduced.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1977
Accession Number
ADA048470

Entities

People

  • C. O. Hulse

Organizations

  • United Technologies Corporation

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Ceramic Matrix Composites
  • Composite Materials
  • Eutectic Composites
  • Failure Mode And Effect Analysis
  • Gas Turbines
  • Material Degradation Processes
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Mechanical Properties
  • Mechanics
  • Melting Point
  • Phase Diagrams
  • Refractory Metals
  • Turbine Components
  • Turbines

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.
  • Surface Engineering/Surface Coating Technology.