Fluxless brazing of aluminum in inert gas
US4240574A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1978 |
| Grant date | Dec 23, 1980 |
| Priority date | — |
| Expiry date | Mar 13, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2101/14
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of brazing aluminum parts in an inert gas atmosphere is disclosed. The brazed filler metal is controlled to contain a ternary alloy of aluminum-silicon-magnesium and the base aluminum parts are controlled to contain a binary alloy of aluminum-magnesium. Magnesium in the base metal is controlled to 0.4-1.2% and in the filler metal it is controlled to 0.2-0.6%; in the filler metal only, silicon is controlled to 7-12%. The assembled base metal parts and filler metal are subjected to differential heating rates, one rate being limited to at least 50.degree. C./minute when the metal parts reach temperatures in the range of 400.degree.-550.degree. C., and a conventional rate when outside said temperature zone. As a result, three physical parameters are caused to occur simultaneously: initiation of porosity in oxide film on the metal parts, transport of magnesium to the oxide interface and reaction with the oxide, and initial melting of the filler metal as well as wettings of the oxide by the filler metal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.