GLASS-FORMATION IN THE SYSTEM Y2O3-AL2O3-SIO2 UNDER CONDITIONS OF LASER MELTING

Glass formation in the Y2O3-Al2O3-SiO2 system was investigated by means of laser melting using a CO2 laser source (wavelength 10.6 mum) with a maximum output power of 1700 W. The glass-forming region was found to be more extensive than that observed by other investigators. No glassy phase formed in compositions with less than 20 wt% SiO2. A non-equilibrium phase diagram corresponding to the conditions of laser-induced rapid melting and self-quenching was also determined. All the phases reported in the relevant binary diagrams with the exception of yttrium silicate 2Y2O3 . 3SiO2 were observed.