Sinterable Ceramic Powders from Laser-Heated Gases.

Abstract

Extremely high quality ceramic powders have been synthesized from SiH4, NH3, and CH4 reactant gasses that are heated by absorbing energy emitted from a CO2 laser. Resulting Si, Si3N4 and SiC powders have been characterized in terms of parameters which are important for densification processes. The powders are virtually ideal. The fully dispersible powders have mean diameters ranging from 0.1-0.3 um with a standard deviation that is typically 25-45%. As synthesized powders are extremely high purity because the synthesis equipment is hermetic and cold-walled. The synthesis process has been modeled on a macro scale with respect to heat-transfer, fluid-flow and stability criteria. These results have permitted the process to be scaled safely to production rates up to 8-40 tons/year/nozzle. Keywords: Ceramic powder synthesis; Laser induced gas-phase reactions; Ceramic powder; Particle nucleation kinetics; Nitriding kinetics; Silicon carbide; Silicon nitride.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1988
Accession Number
ADA194162

Entities

People

  • John S. Haggerty

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Alcohols
  • Aluminum Oxides
  • Ceramic Materials
  • Chemical Synthesis
  • Chemistry
  • Crystal Structure
  • Heat Transfer
  • Materials
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Measurement
  • Mechanical Properties
  • Mechanics
  • Organic Chemistry
  • Particle Size
  • Refractive Index

Readers

  • Mathematics or Statistics
  • Organic Chemistry
  • Powder metallurgy of Titanium alloys.

Technology Areas

  • Directed Energy