The Impact of Compositional Variations and Processing Conditions on Secondary Phase Characteristics in Sintered Silicon Nitride Materials

  • W. Braue
  • G. Wötting
  • G. Ziegler
Part of the Materials Science Research book series (MSR, volume 21)

Abstract

The effect of secondary phase characteristics and processing conditions on microstructural development during liquid-phase assisted sintering of silicon nitride and the relation to mechanical properties at room-temperature are outlined. The results clearly show that for the mechanical properties up to about 1000°C the aspect ratio of the elongated β-phase is a decisive parameter. It is concluded that the aspect ratio is mainly controlled by the viscosity of the liquid phase. The impact of secondary phase characteristics, especially its structure and viscosity, on high-temperature strength is discussed. As an example the relationship between powder properties, secondary phase characteristics and high- temperature strength is given. It will be shown that an improvement in high temperature strength is possible by (partial) devitrification of the usually amorphous residuals.

Keywords

Porosity Crystallization Silicate Chlorine Nitride 

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Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • W. Braue
    • 1
  • G. Wötting
    • 2
  • G. Ziegler
    • 2
  1. 1.Center for Solid State ScienceArizona State UniversityTempeUSA
  2. 2.Institute for Materials ResearchGerman Aerospace Research Establishment (DFVLR)Köln 90Germany

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