This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Inert Atmosphere Fluxless Brazing of Aluminum Heat Exchangers
Annotation ability available
Sector:
Language:
English
Abstract
Long Manufacturing uses a novel fluxless brazing process for the production of aluminum heat exchangers. Unlike more established vacuum brazing methods, the Long process does not depend on the use of a magnesium promoter. Instead, Al-Si clad brazing sheet is pretreated with a thin nickel alloy coating. This nickel coating reacts exothermically with the aluminum surface during brazing, to accomplish oxide penetration. Small amounts of lead are co-deposited with the nickel to improve wetting.
The nickel coating inhibits oxidation during preheat, permitting brazing to be accomplished in an inert gas furnace. This offers furnace cost and process reliability benefits in comparison to conventional vacuum brazing.
This paper describes the mechanisms of nickel brazing, in comparison to established models for vacuum brazing. Practical process control implications are also described.
Recommended Content
Topic
Citation
Cheadle, B. and Dockus, K., "Inert Atmosphere Fluxless Brazing of Aluminum Heat Exchangers," SAE Technical Paper 880446, 1988, https://doi.org/10.4271/880446.Also In
References
- Swaney, O.W. Trace, D.E. Winterbottom, W.L. Brazing Aluminum Automotive Heat Exchangers in Vacuum: Process and Materials Welding Journal May 1986
- Terrill, J.R. Cochran, C.N. Stokes, J.J. Haupin W.E. Understanding the Mechanisms of Aluminum Brazing 50 12 Dec. 1971
- Creber, D.K. Ball, J. Field, D.J. A Mechanistic Study of Aluminum Vacuum Brazing S.A.E. Paper No. 870185 Feb. 1987
- Feduska, W. Welding Journal 38 3 March 1959 Research Supplement 122s 131s
- Winterbottom, W.L. Vacuum Brazing of Aluminum: Auger Studies of Wetting & Flow Characteristics J. Vac. Sci. Technology 13 1976
- Phillips, H.W.L. Journal of Institute of Metals 1942 68 27
- Dockus, K.F. Fluxless Bonding for Aluminum Components Welding Journal Oct. 1978