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:
Mar. 13, 1979
Filed:
Oct. 05, 1977
Walter L Winterbottom, Farmington Hills, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A method of fluxless brazing of aluminum parts is disclosed. Gaseous species, such as O.sub.2 and H.sub.2 O, which inhibit wetting are controlled by rapid heating (at least 100.degree. C./min) through a critical temperature range (such as 400.degree.-590.degree. C.) during heat-up to brazing temperatures. The formation of porosity through the oxide film and the collection of a promoter and wetting agent at the interface with the oxide film will thus occur simultaneously precluding disruption of wetting action by gaseous O.sub.2 or H.sub.2 O. Wicking of the wetting agent through the film porosity in the critical temperature range will then take place because of the limited time available for the reaction of gaseous O.sub.2 and H.sub.2 O with the film to form a duplex oxide. Heating may be carried out in a vacuum of 10.sup.-3 Torr or less or in an inert atmosphere with pulsed heating, provided the critical heating rate is observed in said critical temperature range.