Removal of oxide layers from titanium castings using an alkaline earth deoxidizing agent
AssigneeRMI Titanium Company
InventorsRichard L. Fisher, Stanley R. Seagle
Life of this patent
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Abstract
The invention relates to a process for the removal of oxides and/or oxygen which are formed on the surface of the casting during the investment casting process to levels that are comparable to those found within the bulk of the metal casting thus reducing the inherent hardness of the surfaces of the casting. More specifically, the invention relates to a process for removing oxide layers from titanium casting using an alkaline earth deoxidizing agent.
Claims14
A process for removing oxygen from oxide and/or oxygen enriched layers which are formed on the surface of a metal casting of titanium or titanium alloy during the casting process to levels equal to or below concentrations found in the interior of the casting comprising:
- (a) contacting a metal casting of titanium or titanium alloy having oxide and/or oxygen enriched layers formed on the surface thereof with a metal deoxidant in a dry, inert atmosphere at an elevated temperature sufficient to at least vaporize the metal deoxidant and maintaining contact of the vaporized metal deoxidant with the surface of said casting to form metal deoxidant oxide until the oxide and/or oxygen in the surface is reduced to substantially equate the concentration thereof in the interior of the casting;
- and
- (b) acid washing the casting to remove metal deoxidant oxide on the surface of the casting.
A metal casting of titanium or titanium alloy wherein the oxide and/or oxygen levels in the casting surface is substantially equal to the levels of oxide and/or oxygen in the interior of said casting.
Dependencies are inferred from the claim text.