Glaskeramik und Verfahren zu ihrer Herstellung

摘要

An infrared transparent glass ceramic article is useful for top plates of cooking stoves and has a black appearance but an infrared transmittance of about 80% or more for an infrared light of a wavelength 1,500 nm, and beta -quartz solid solution crystals substantially alone dispersed within glassy matrix without any other crystals. The article consists essentially, by weight, of 60-72% SiO2, 14-28% Al2O3, 2.5-5.5% Li2O, 0.1-0.9% MgO, 0.1-0.9% ZnO, 3-6% TiO2, 0.03-0.5% V2O5, 0.1-1% Na2O, 0-1% K2O, 0-2% CaO, 0-2% BaO, 0-2% PbO, 0-2% As2O3, 0-3% ZrO2, and 0-3% PdO5. The article is produced by forming a desired shape of glass article having the ingredients, heating the glass article at a temperature of 650 DEG -800 DEG C. to nucleate in the glass, heating the glass article at a temperature of 800 DEG -950 DEG C. to thereby precipitate beta -quartz solid solution crystals alone in the glass, and cooling the article to the room temperature.