Ceramic Sintering

Abstract

Measurement of the rate of oxidation and creep rate in air of chemically vapor deposited Si3N4 at around 1500C are reported. Attempts to prepare pure, dense Si3N4 bodies by hot pressing powder at ultra-high pressures were unsuccessful. Resistance heaters made of dense, sintered SiC were tested and found to have in-use lifetimes very much longer than those of commercially available heaters tested in the same way. Microscopic examination of the structures developed during the initial stage sintering of SiC doped with C and B indicates that these dopants inhibit surface diffusion until densification begins at around 1500C. Bodies of B4C having about 94% of theoretical density were made by using conventional sintering processes and doping the powder with either SiC or Be4C.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1974
Accession Number
ADA001012

Entities

People

  • Charles D. Greskovich
  • Joseph H. Rosolowski

Organizations

  • General Electric

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Ceramic Materials
  • Chemical Analysis
  • Chemical Vapor Deposition
  • Chemistry
  • Electron Microscopy
  • Grain Boundaries
  • Grain Growth
  • Grain Size
  • High Temperature
  • Hot Pressing
  • Materials
  • Measurement
  • Particle Size
  • Physical Chemistry
  • Roughness
  • Silicon Carbide
  • Surface Temperature

Fields of Study

  • Materials science

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Fluid Dynamics.
  • Powder metallurgy of Titanium alloys.