Metal fluoride glasses in the CdF.sub.2 -PbF.sub.2 -AlF.sub.3 -(LiF) system
AssigneeCorning Glass Works
InventorPaul A. Tick
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Abstract
Novel halide glass-forming compositions in the CdF.sub.2 -AlF.sub.3 -PbF.sub.2 and CdF.sub.2 -AlF.sub.3 -PbF.sub.2 -LiF composition fields are disclosed which exhibit unusual glass stability. The constituents of these glasses are potentially vapor transportable, so that very pure glass articles exhibiting excellent infrared transparency can be envisioned.
Claims7
A non-oxide, metal-fluoride-containing glass-forming composition comprising, in mole percent, about 20-46% CdF.sub.2, 22-52% AlF.sub.3, 18-44% PbF.sub.2, and at least 80% total of CdF.sub.2 +AlF.sub.3 +PbF.sub.2, the mole ratio of CdF.sub.2 :PbF.sub.2 in the composition being greater than 1:2.
A non-oxide, metal-fluoride glass article produced from a glass having a crystallization temperature T.sub.xtal at least 75.degree. C. higher than its transition temperature T.sub.g and a composition which consists essentially, in mole percent, of about 20-46% CdF.sub.2, 22-52% AlF.sub.3, 18-44% PbF.sub.2, at least 80% total of CdF.sub.2 +AlF.sub.3 +PbF.sub.2, and 5-15% LiF, and, optionally, up to 10% total of fluorides selected from the group consisting of YbF.sub.3, CaF.sub.2, SrF.sub.2, BaF.sub.2, NaF and KF, and up to 5% of ZnF.sub.2, the mole ratio of (CdF.sub.2 +ZnF.sub.2 +CaF.sub.2 +SrF.sub.2 +BaF.sub.2):PbF.sub.2 in the composition being greater than 1:2.
Dependencies are inferred from the claim text.