Fluxless braze processing of aluminum
US4143802A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1977 |
| Grant date | Mar 13, 1979 |
| Priority date | — |
| Expiry date | Oct 5, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K1/19
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.