Aircraft transparency having chemically tempered lithia-alumina-silica containing glass and method of making the chemically tempered glass

摘要

An aircraft transparency in a glass piece, wherein the glass piece includes a chemically tempered first major surface and a chemically tempered opposite second major surface, a first case depth begins at the first major surface, a second case depth begins at the second major surface, and a tensile stress zone is within the glass piece between the end points of the first and the second case depths. The glass between the end points of the first and second case depth has a glass composition including: Ingredient Percent by weight SiO2 60 to 75; Al2O3 18 to 28; and Li2O 3 to 9, and the glass has at least one of the following properties (a) a log 10 viscosity temperature of at least 1413° F. and (b) a liquidus temperature of at least 2436° F.