Paper Title:
Oxynitride Glasses: Preparation, Properties and Implications for Mechanical Behaviour of Silicon Nitride
  Abstract

Oxynitride glasses are found at grain boundaries, i.e. triple point junctions and intergranular films, in silicon nitride based materials as a result of cooling of liquid phases formed by reaction of sintering additives with silicon nitride and silica present on the nitride surface during the densification of the ceramics. The glass chemistry, particularly the content of modifying cation, usually Y or a rare earth (RE) ion, and the volume fractions of these oxynitride glass phases within the ceramic affect the properties of silicon nitride such as fracture toughness and creep at high temperature. As nitrogen substitutes for oxygen in silicate and alumino-silicate glasses, increases are observed in glass transition and softening temperatures, viscosities (by two to three orders of magnitude), elastic moduli and microhardness. If changes are made to the RE:Si:Al ratios or as the size of the rare earth cation decreases, properties such as viscosity can be increased by a further two to three orders of magnitude. These effects have a strong impact on the mechanical properties of silicon nitride based ceramics, especially creep resistance. This paper provides an overview of previous work on oxynitride glasses and outlines the effect of glass composition on their properties and discusses the implications for high temperature behaviour of Si3N4 ceramics.

  Info
Periodical
Edited by
Hasan Mandal
Pages
11-16
DOI
10.4028/www.scientific.net/MSF.554.11
Citation
S. Hampshire, M. J. Pomeroy, "Oxynitride Glasses: Preparation, Properties and Implications for Mechanical Behaviour of Silicon Nitride ", Materials Science Forum, Vol. 554, pp. 11-16, 2007
Online since
August 2007
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Sheldon M. Wiederhorn, Ralph F. Krause, František Lofaj, U. Täffner
Abstract:New data are presented on the tensile creep behavior of silicon nitride sintered with Lu2O3. The data are compared with two earlier sets of...
381
Authors: H.B. Li, Jun Ting Luo, Kai Feng Zhang
Abstract:The amorphous nano-sized silicon nitride powders were sintered by liquid phase sintering method. Si3N4-Si2N2O composites were in-situ...
1069
Authors: Małgorzata Sopicka-Lizer, Tomasz Pawlik, Tomasz Włodek, Marta Tańcula, Galina Chernik
Abstract:The results on the effect of nanostructured β-sialon precursor on the sintering and properties of the resultant ceramics are presented. The...
179
Authors: Wei Ru Zhang, Feng Sun, Ting Yan Tian, Xiang Hong Teng, Min Chao Ru, Yan Ding
Abstract:Silicon nitride ceramics were prepared by gas pressure sintering (GPS) with different sintering additives, including La2O3, Sm2O3 and Al2O3....
27
Authors: Hai Jiang, Chun Yan Tian
Chapter 2: Micro/Nano Materials and Equipments
Abstract:Silicon nitride nanoceramics were fabricated by hot press sintering two kinds of Si3N4 nano-sized powders. The effect...
239