Strengthening of transparent glass-ceramics: effects of glass composition and crystallization
TALIMIAN A. 1, GALUSEK D. 1,2
1 Centre for Functional and Surface Functionalised Glass, Alexander Dub?ek University of Tren?ín, Študentská 2, Trencin, Slovakia; 2 Joint Glass Centre of the IIC SAS, TnUAD and FChPT STU, Študentská 2, Trencin, Slovakia
The mechanical performance of glass ceramics is determined by the properties of both the crystalline phases and residual glass. In this study, transparent glass-ceramics in Na2O-MgO-Al2O3-SiO2 (NMAS) system were synthesized using a combination of titania, tin dioxide, and zirconia as nucleating agents. The influence of the nucleating agents and the substitution of MgO with ZnO on the physical properties, phase composition, and viscoelastic behavior of glass ceramics was studied. The produced glass ceramics were subjected to Na+/K+ ion exchange in molten KNO3. The penetration of potassium into the glass surface was investigated using electron microprobe analysis. The effects of Na+/K+ ion exchange on the mechanical properties of glass ceramics were investigated using indentation methods. The changes in cracking behavior, e.g. the critical load of cracking and geometry of cracks, were studied to investigate the dependence of the mechanical behavior of glass ceramics on chemical concentration profiles produced by the ion exchange. The impacts of present crystalline phases and residual glass on stress build-up and relaxation during ion exchange, surface damage resistance, mechanical strength, and fracture toughness of glass ceramics are critically discussed.
Acknowledgment
This paper is a part of the dissemination activities of project FunGlass. This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 739566. Financial support of this work by VEGA 2/0028/21 is gratefully acknowledged.