Nitridation Effect On Properties Of Stannous-Lead Phosphate Glasses

Stannous-lead phosphorus oxynitride glasses were prepared by remelting under an anhydrous ammonia atmosphere. Glasses that contained up to ~4.2wt% (9 at.%) of nitrogen were obtained. The rate of nitrogen dissolution was studied as a function of remelting time (3-66h) and temperature (400-600 deg C). The onset nitridation temperature was extrapolated to be 315 deg C; higher nitridation temperatures accelerated nitrogen dissolution. Nitridation of the stannous-lead oxyphosphate glasses decreased the dissolution rate in water and the thermal expansion coefficient; however, it increased the dilatometric softening temperature, the glass-transition temperature, the microhardness, and the density.