Effect Of Ion Exchange On The Sinter-Crystallisation Of Low Expansion Li2O-Al2O3-Sio2 Glass-Ceramics

In this work, an ion exchange treatment to minimize surface crystallisation and thus improve the sintering of compacts made of glass particles is proposed. The concept was tested by subjecting glass powders of teh LiO2-Al2O3-SiO2 (LAS) system to molten KNO3 ion exchange treatment aimed at developing a low thermal expansion glass-ceramic via sinter-crystallisation. The relative densities of treated and untreated glass powder compacts sintered at different temperatures were compared and suitable IE and sintering temperatures were selected. Optical microscopy, x-ray diffraction, dilatometry and SEM were used to characterise the sintered samples.