Phase Relations in the Si3N4-SiO2-MgO System and Their Interrelations with Strength and Oxidation Resistance. Dense Si3N4: Interrelation between Phase Equilibria, Microstructure and Mechanical Properties

Abstract

Phase equilibria studies between 1400 C and 1750 C have established three important tie lines in the Si3N4-SiO2-MgO system, viz., Si3N4-MgO, Si3N4- Mg2SiO4, and Si2N2O-Mg2SiO4. Strength measurements at 1400 C for fixed Si3N4 molar contents and varying MgO/SiO2 molar ratios show that the maximum high temperature strengths can be obtained for MgO/SiO2 molar ratios that approach zero and infinity. The oxidation of these materials will be discussed in terms of the compatibility of SiO2 (the oxidation product of Si3N4) and the other phases present in the material.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1976
Accession Number
ADA030408

Entities

People

  • F. F. Lange

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Ceramic Materials
  • Chemical Synthesis
  • Chemistry
  • Composite Materials
  • Crystal Structure
  • Elastic Properties
  • Flexural Strength
  • Grain Boundaries
  • High Temperature
  • Hot Pressing
  • Magnesium Compounds
  • Materials
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Oxidation
  • Oxidation Resistance

Fields of Study

  • Materials science

Readers

  • Analytical Chemistry
  • Reinforced Composite Materials
  • Theoretical Analysis.