Densification and Microstructure of Sodium-doped Colloidal Mullite

Author

William Fahrenholtz, Missouri University of Science and TechnologyFollow
Douglas M. Smith

Abstract

A series of mullite precursor gels to prepared by hetero-coagulation of boehmite and colloidal silica. Samples were doped with up to 1.5 wt% Na2O. Na2O additions as low as 0.16 wt% led to the formation of α-alumina and a stable glassy phase in addition to mullite. No evidence for the incorporation of sodium into the mullita structure was found by either XRD or 27AlMAS NMR. SEM showed mullite doped with 0.16 wt% and greater Na2O had an inter-granular glassy phase and large crystalline grains. It is thought that the majority of the sodium was present in the glassy phase. Sodium addition did not decrease the mullite crystallization temperature and did not lead to enhanced sintering.

Recommended Citation

W. Fahrenholtz and D. M. Smith, "Densification and Microstructure of Sodium-doped Colloidal Mullite," Journal of the American Ceramic Society, Wiley-Blackwell, May 1994.

The definitive version is available at https://doi.org/10.1111/j.1151-2916.1994.tb05421.x

Department(s)

Materials Science and Engineering

International Standard Serial Number (ISSN)

0002-7820; 1551-2916

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1994 Wiley-Blackwell, All rights reserved.

Publication Date

01 May 1994