LITHIA-ALUMINA-SILICA CONTAINING GLASS COMPOSITIONS AND GLASSES SUITABLE FOR CHEMICAL TEMPERING AND ARTICLES MADE USING THE CHEMICALLY TEMPERED GLASS

摘要

A glass composition for chemical tempering includes oxides in wt% ranges of: SiO2 60 to 75; Al2O3 18 to 28; Li2O 3 to 9; Na2O 0 to 3; K2O 0 to 0.5; CaO 0 to 3; MgO 0 to 3; ZrO2 0 to 3; where MgO + CaO is 0 to 6 wt%; Al2O3 + ZrO2 is 18 to 28 wt%, and Na2O + K2O is 0.05 to 3.00 wt%. The glass has a log 10 viscosity temperature in the temperature range of 1328OF (720OC) to 1499OF (815OC); a liquidus temperature in the temperature range of 2437OF (1336OC) to 2575OF (1413OC), and a log 7.6 softening point temperature in the temperature range of 1544OF (840OC) to 1724OF (940OC). The chemically tempered glass has, among other properties, an abraded modulus of rupture of 72 to 78 KPSI, and a modulus of rupture of 76 to 112 KPSI.