Preparation, structural and thermo-mechanical properties of lithium aluminum silicate glass-ceramics

Lithium aluminum silicate glasses of composition (wt%) 12.6Li(2)O-71.7SiO(2)-5.1Al(2)O(3)-4.9K(2)O-3.2B(2)O(3)-2.5P(2)O(5) were prepared by the melt quench technique. These glasses were converted to glass-ceramics based on DTA data. X-ray diffraction (XRD) and Fourier transform infra-red spectroscopy (FTIR.) were used to discern the phases evolved in the glass-ceramics. Phase morphology was studied using scanning electron microscopy (SEM). Thermal expansion coefficient (TEC) and glass transition temperature (T-g) of all samples were measured using thermo-mechanical analyze (TMA). It was found that 3 It dwell time at crystallization temperature yielded samples with good crystallinity with a TEC of 9.461 x 10(-6) degrees C-1. Glass-ceramic-to-metal compressive seal with SS-304 was fabricated using LAS glass-ceramic. The presence of metal housing and compressive stresses at the glass-ceramic-to-metal interface reduced average grain size and changed the overall microstructure. (C) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved.