Phase Relationships in High Temperature Ceramics. Phase 1

Abstract

The objective of this work was to establish an efficient means of determining the high temperature phase behavior of the HfO2-Ta2O5 system under conditions of relevance to their potential use in propulsion system environments. A primary objective was to establish melting temperatures for the mixed oxides and to identify phases formed in the high temperature portions of the phase diagram, above 2500 F (1400 C). The approaches evaluated included traditional anneal quench studies and use of CO2 laser heating in controlled atmospheres. Melting points were measured using an optical pyrometer/laser fusion approach. Phases formed were characterized primarily by x-ray diffraction and electron microscopy. the liquidous curve for the oxide system has been established and two new phases identified for the oxide system. Keywords: Ceramics, Phase diagram, Solubility.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1987
Accession Number
ADA204630

Entities

People

  • R. P. Turcotte

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Weapons Technologies

DTIC Thesaurus Topics

  • Advanced Materials
  • Corporations
  • Crystal Structure
  • Diffraction
  • Electron Microscopes
  • Electron Microscopy
  • High Temperature
  • Laser Beams
  • Materials
  • Materials Science
  • Measurement
  • Melting Point
  • Microscopy
  • Optical Pyrometers
  • Physics Laboratories
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Physics

Readers

  • Materials Science and Engineering.
  • Surface Engineering/Surface Coating Technology.
  • Systems Analysis and Design

Technology Areas

  • Directed Energy
  • Directed Energy - Pulsed-Laser Deposition
  • Microelectronics
  • Microelectronics - Graphene