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 1328° F. (720° C.) to 1499° F. (815° C.); a liquidus temperature in the temperature range of 2437° F. (1336° C.) to 2575° F. (1413° C.), and a log 7.6 softening point temperature in the temperature range of 1544° F. (840° C.) to 1724° F. (940° C.). 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.
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