Microwave (Hybrid) Heating of Alumina at 2.45 GHZ: II. Effect of Processing Variables, Heating Rates and Particle Size

Abstract

Microwave (hybrid) heating (MHH) is a novel combination of microwave (MW)-material interaction and conventional radiant/conduction mechanisms that facilitates the attainment of very high heating rates In a 2.45 GHz. multimode MW cavity. Dry-pressed green samples of pure, undoped alumina were fired under similar conditions by MHH and conventional fast firing (CFF). The effect of processing variables (temperature, time) and heating rates on MHH and CFF were Investigated. The effect of particle size on the MHH phenomena was also studied. MHH has been shown to result in accelerated densification (higher densification to coarsening ratios) relative to CFF under the same conditions of temperature and time. Higher heating rates with MHH result in higher densities and smaller grain sizes. Smaller starting particle sizes with MHH also culminate In the highest densities and the largest grain sizes similar to conventional firing.

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Document Details

Document Type
Technical Report
Publication Date
Apr 27, 1992
Accession Number
ADP007745

Entities

People

  • Arindam De
  • David E. Clark
  • E. D. Whitney
  • Iftikhar Ahmad

Organizations

  • University of Florida

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Critical Temperature
  • Crystal Structure
  • Diffusion
  • Energy
  • Engineering
  • Grain Boundaries
  • Grain Growth
  • Grain Size
  • Heat Of Activation
  • Materials
  • Materials Processing
  • Microwaves
  • Particle Size
  • Particles
  • Powders
  • Silicon Carbide
  • Sintering

Readers

  • Astronomy/Astrophysics
  • Electronics Engineering
  • Powder metallurgy of Titanium alloys.