Surface devitrification of high temperature sealing glass

Abstract

This paper is focused on surface phase separation, nucleation and crystal growth of a high temperature sealing glass. Different glass surface polishing conditions have been examined and their effect on the glass devitrification during the thermal treatment is studied. The glass microstructure evolution starts with phase separation followed by the break-up of elongated new phases. Nucleation initiates first from the surface defects followed by random locations. After the nucleation process, crystalline phase growth kinetics dominates. Nuclei number density affects both crystallite size and growth direction. Lower nuclei number density leads to larger crystalline sizes even though the formation of these nuclei is delayed. Glass stability is discussed from glass network connectivity point of view.

Keywords:

• Phase separation
• Sealing glass
• Microstructure evolution
• Kinetics
• Polishing
• Devitrification

This work was supported by Department of Energy under Award number DE-FC07-06ID14739 and Office of Naval Research under Award number N00014-11-1-0266. Part of the XRD results is based upon work supported by National Science Foundation under grant no. DMR-0923107. The authors acknowledge the help from Gilles Divoux, Dr Robert B. Moore research group, Chemistry Department, Virginia Tech.

Notes

This paper is part of a special issue on Energy Materials