A new two-step heating process was recently developed for the strengthening of mica glass ceramics. Two mechanisms of subsequent toughening were applied by the second heat treatment: (i) the crystallization of a second silicate phase (i.e. anorthite) and (ii) the transformation toughening by addition of Zr02. Transmission-electron-microscopy (TEM) studies were performed to investigate in detail the microstructure development in this two-step heating process. In principle, the crystallization mechanisms were found to be similar for all samples investigated. However, the resulting microstructures differed significantly even after small compositional changes.
Origin
Fraunhofer-Inst Silicatforschung, Germany
Journal Title
Proc Xvii Icg Vol 5 Beijing 1995 241-246
Sector
Glass Ceramics
Class
GC 421