You are not logged in Total: 7journals, 20,671articles Online
Login / Register
Forgot Login?
Main menuMain menu
What's new
Journal list
Visiting ranking
Phrase ranking
About us
Journal Site
Advanced Search

Home  >  Journal list  >  Journal of the Ceramic Society of Japan  >  Vol.116  No.1355 (July) (2008)  >  pp.786-791

Journal of the Ceramic Society of Japan
<<Previous article Vol.116  No.1355 (July) (2008)   pp.786 - 791 Next article>>

Influence of Na2O contamination on changing the cristobalite phase into amorphous in mullite ceramics with excess silica

Shigeo HAYASHI1), Takashi SATO1), Yutaka OHYA2) and Zenbe-e NAKAGAWA1)
1) Faculty of Engineering and Resource Science, Akita University
2) Faculty of Engineering, Gifu University

  Authors have been trying to fabricate cristobalite-containing mullite bodies with high strength and toughness by reheating mullite-glass sintered bodies. In this process, a phenomenon that once-crystallized cristobalite layer changed back to amorphous again was observed by the microstructure observation of the sample contaminated with Na2O. In this study, the minimum amount of Na2O to change the cristobalite phase into amorphous was quantitatively determined by the electron probe microanalysis (EPMA) method. As a result, the amount of Na2O in the amorphous phase just near the cristobalite-amorphous phase boundary was 1.6-1.9 mass%, which almost corresponded with the minimum amount of Na2O in the liquid phase coexisting with mullite, estimated from a phase diagram.

Mullite-glass ceramics, Annealing treatment, Na2O contamination, Cristobalite, Amorphous phase

Received: December 11, 2007
Accepted: April 17, 2008 , Published online: July 01, 2008
Copyright (c) 2008 The Ceramic Society of Japan



Terms of Use | Privacy Policy