Synthesis, Structure, and Properties of Zirconia-Modified Aluminosilicate Glass-Ceramics

Abstract

Strontium aluminosilicate glass-ceramics modified with zirconia additions in the presence of yttria as a stabilizing oxide and without it have been prepared by a sol–gel process. Increasing the zirconia content from 5 to 15 wt % has been shown to reduce the gelation time of the starting solutions, lower the gel crystallization onset temperature, activate the glass-ceramic sintering process, and increase the critical stress intensity factor (KIc) of the glass-ceramics by more than a factor of 2. The present results confirm that the increase in KIc on the addition of ZrO2 is due to transformation toughening. At the same time, the addition of yttria as a stabilizing oxide has been shown to hinder the martensitic transformation of tetragonal ZrO2 into the monoclinic phase.