Processing of Nanocrystalline Nitrides and Oxide Composites

Abstract

Pressureless sintering of nanocrystalline AlN was achieved at remarkably low temperatures of 160 deg C and 155 deg C using coarse grained and nanocrystalline yttria additives, respectively. X-Ray diffraction studies showed that the nanocrystalline AlN materials obtained by our approach have a very low oxygen content, confirming FNAA results. The high purity and high density associated with our pressureless sintered undoped nanocrystalline AlN pellets gave rise to greater thermal conductivity values than hot-pressed conventional AlN. Yttria-doped nanocrystalline AlN pellets attained high density and high thermal conductivity (148 W/m-K) without resorting to special sintering conditions/treatments.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1999
Accession Number
ADA369525

Entities

People

  • Jackie Y. Ying
  • Martin L. Panchula

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Aluminum Nitrides
  • Chemical Engineering
  • Chemical Reactions
  • Coefficients
  • Composite Materials
  • Conductivity
  • Diffraction
  • Heat Treatment
  • Hot Pressing
  • Liquid Phases
  • Low Temperature
  • Materials
  • Sintering
  • Thermal Conductivity
  • Thermal Diffusivity
  • X Rays
  • X-Ray Diffraction

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.
  • Thermal Physics or Thermal Science.