The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 04, 2000
Filed:
Nov. 21, 1997
Herbert S Goode, Jr, Kent, WA (US);
Jean A Nielsen, Kent, WA (US);
Larry E Nitzsche, Bellevue, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
The plasma descaling process of the present invention removes surface oxides selectively from structural metal surfaces, especially titanium and its alloys, and, with appropriate control of the reaction temperature, is self-limiting to avoid cracking problems otherwise associated with intergranular attack. In a preferred embodiment of the present invention, a fluoride plasma reacts with surface oxides on a titanium alloy to remove scale and alpha case in a temperature controlled chamber without attacking the underlying crystalline metal to cause intergranular attack. Properly controlled by regulating the chamber temperature, the plasma reaction terminates when the plasma has removed the surface oxides and encounters the underlying crystalline metal. The product is a metal surface free of scale and alpha case and free of intergranular attack. The plasma descaling process replaces conventional metal finishing processes, such as chemical milling or etching.