Glass Formation and Properties of Glasses in the System Na2O-B2O3-SiO2-TiO2

An investigation was made of the effect of TiO₂ on the glassforming region and on the physical properties of glasses in the system Na₂O-B₂O₃-SiO₂TiO₂. Glasses containing up to 45 mole % TiO₂ may be formed with an alkali content of 30 mole %. At lower alkali contents (10 mole % Na₂O) glasses may be formed containing up to 22 mole % TiO₂. The way in which the coefficient of linear thermal expansion and the transformation and softening temperatures are affected by TiO₂ additions has been determined.