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US 4,790,874 AGranted
Method for forming metals with reduced impurity concentrations
AssigneeHowmet Turbine Components Corporation
InventorNick G. Lirones
Life of this patent
Estimating the term…
Abstract
A method of purifying molten metal that reduces the amount of contaminants therein by maintaining the molten metal in a quiescent state allowing buoyant impurities in the metal to float to the top. The top of the molten metal is cooled solidifying the top portion and entrapping the impurities in the solid layer. The molten metal is then cast from beneath the solid portion.
Claims5
A method of purifying molten metal comprising the steps of:
- (a) providing an inert atmosphere;
- (b) melting said metal in said atmosphere to form molten metal;
- (c) placing said molten metal in a container;
- (d) maintaining the molten metal in a quiescent state to allow buoyant impurities therein to float to the top of the molten metal;
- (e) cooling the top of said molten metal to solidify the top portion of said molten metal to form a solid layer for entrapping said impurities in said solid layer;
- (f) melting the portion of said solid layer adjacent said container;
- and
- (g) pouring said molten metal from beneath said solid layer.
5 more elements
Dependencies are inferred from the claim text.