Chapter 22. Observations on the Glass Phase Composition in Porcelains

  1. William M. Carty
  1. William M. Carty

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294734.ch22

Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 23, Issue 2

Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 23, Issue 2

How to Cite

Carty, W. M. (2008) Observations on the Glass Phase Composition in Porcelains, in Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 23, Issue 2 (ed W. M. Carty), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294734.ch22

Author Information

  1. Whiteware Research Center, New York State College of Ceramics at Alfred University, Alfred, New York

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2002

ISBN Information

Print ISBN: 9780470375778

Online ISBN: 9780470294734

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Keywords:

  • porcelains;
  • glass phase composition;
  • quantitative crystalline phase composition;
  • mullite;
  • firing

Summary

The composition of the glass phase in a fired porcelain sample can be calculated exactly by taking the diference of the bulk chemical analysis and the quantitative crystalline phase composition obtained from powder X-ray difraction. Data indicates that all of the glass phase compositions are similar at any given heat treatment temperature. The ratio of alkali (R2O) to alumina (Al2O3) is essentially constant over the firing temperature range of 1150–1400°C. It is therefore proposed that the glass phase composition oftri-axial porcelains lies on the glass formation boundary within the R2O-Al2O3-SiO2 system. This observation has important implications for fast-firing pyroplastic deformation, and fired strength of porcelains, and can be used to explain many of the inconsistencies in the published literature.