Single phase glass compositions for use in protective and lubricating coatings for the heat treatment and hot working of metals
AssigneeDaniel Doncaster & Sons Limited
InventorAnthony N. Skedgell
Life of this patent
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Abstract
The coatings are glass compositions which consist essentially of from 18 to 45 mol % of the alkaline oxides CaO and one or both of Na.sub.2 O and K.sub.2 O and from 5 to 22 mol % of Al.sub.2 O.sub.3, the balance being B.sub.2 O.sub.3 and SiO.sub.2 in such amounts that the molar ratio of B.sub.2 O.sub.3 : (B.sub.2 O.sub.3 +SiO.sub.2) lies in the range from 0.575:1 to 0.85:1. The molar ratio of K.sub.2 O: (K.sub.2 O+Na.sub.2 O) is from 0.4:1 to 0.6:1 and CaO is 48 to 52 mole % of the alkaline oxides. These compositions are particularly suitable for use during the heat-treatment and hot-working of titanium and its alloys.
Claims4
A glass composition which in the molten state forms only a single liquid phase and is suitable for use as a protective and lubricating coating in the heat treatment and hot forming of metals and alloys, the composition consisting essentially of the following alkaline oxides, CaO, Na.sub.2 O and K.sub.2 O and the following acidic oxides, B.sub.2 O.sub.3, SiO.sub.2 and Al.sub.2 O.sub.3, the composition consisting essentially of the alkaline oxides in a total amount of from 18 to 45 mol %, from 5 to 22 mol % of Al.sub.2 O.sub.3, the molar ratio of K.sub.2 O:(K.sub.2 O+Na.sub.2 O) in the range from 0.4:1 to 0.6:1, 48 to 52 mol % of the alkaline oxides being CaO, and the balance being B.sub.2 O.sub.3 and SiO.sub.2 in the molar ratio of B.sub.2 O.sub.3 :(B.sub.2 O.sub.3 +SiO.sub.2) in the range from 0.575:1 to 0.85:1.
Dependencies are inferred from the claim text.