Joining of metal surfaces
AssigneeAlcan Research and Development Limited
InventorsEric Robert Wallace, Ernest William Dewing
Life of this patent
Estimating the term…
Abstract
In methods of joining metal surfaces involving heating to a temperature above about 560.degree.C, the use of a flux comprising a mixture of potassium fluoaluminates. Particularly for brazing aluminum, a flux consisting essentially of potassium fluoaluminate complexes (e.g. KAlF.sub.4 and K.sub.3 AlF.sub.6) may be employed, having a composition corresponding to an AlF.sub.3 /KF ratio, in parts by weight, between about 65:35 and about 45:55. The flux is essentially free of unreacted potassium fluoride and may be in divided solid form.
Claims16
A method of joining by brazing surfaces of metal selected from the class consisting of aluminum and alloys thereof with an aluminum brazing alloy having a melting point lower than that of metal of the surfaces to be joined, comprising:
- a. disposing, for contact, between the surfaces, with exposed metal including a body of the brazing alloy which is to serve for joining the surfaces, a flux comprising a mixture of potassium fluoaluminate complexes and essentially free of unreacted potassium fluoride;
- b. heating the brazing alloy body and flux, in juxtaposed relation to the surfaces to be joined, to a temperature above the brazing alloy melting point for joining the surfaces;
- and
- c. then allowing said body and said surfaces to cool.
A method of joining by brazing surfaces of metal selected from the class consisting of aluminum and alloys thereof with an aluminum brazing alloy having a melting point lower than that of metal of the surfaces to be joined, said method comprising the steps of
- a. disposing, for contact, between the surfaces, with exposed metal including a body of the brazing alloy which is to serve for joining the surfaces, a layer of a flux in finely divided solid form dispersed in water as a slurry, said flux consisting essentially of a mixture of potassium fluoaluminate complexes essentially free of unreacted potassium fluoride;
- b. heating the brazing alloy ahd flux layer, in juxtaposed relation to the surfaces to be joined, to a temperature above the brazing alloy melting point for joining the surfaces;
- and
- c. then allowing the brazing alloy and the surfaces to cool.
Dependencies are inferred from the claim text.