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

Abstract

Lithium aluminum silicate glasses of composition (wt%) 12.6Li 2O–71.7SiO 2–5.1Al 2O 3–4.9K 2O–3.2B 2O 3–2.5P 2O 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 analyzer (TMA). It was found that 3 h dwell time at crystallization temperature yielded samples with good crystallinity with a TEC of 9.461 × 10 −6 °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.