METHOD OF MANUFACTURING A BRAZED ASSEMBLY
The present invention relates to a method of manufacturing a shaped product by means of brazing. The method includes the steps of: producing an intermediate object of metal by rolling or extrusion and having at least one flat surface, coating the at least one surface with a brazing composition comprising a resin, a wax, and a flux and/or flux-producing compound, reshaping the intermediate object into a shaped product, and heating the shaped product to a temperature sufficient to provide at least one brazed connection between defined parts of the shaped product. When a brazing composition is used in this method, it is not necessary to use an additional lubricant during deforming.
1 . A method of manufacturing a shaped product by brazing, the method comprising the steps of:
a. producing an intermediate object of metal by rolling or extrusion and having at least one flat surface,
b. coating the at least one surface with a brazing composition comprising a resin, a wax, and a flux and/or flux-producing compound,
c. reshaping the intermediate object into a shaped product, and
d. heating the shaped product to a temperature sufficient to provide at least one brazed connection between defined parts of the shaped product.
2 . The method according to claim 1 , wherein the metal of the intermediate product is selected from the group consisting of aluminum and aluminum alloy.
3 . The method according to claim 1 , wherein the reshaping at least involves a bending of at least one part of the flat surface of the intermediate product.
4 . The method according to claim 1 , wherein the reshaping of the intermediate product is in the absence of the use of an additional lubricant.
5 . The method according to claim 1 , wherein the product is a folded tube.
6 . The method according to claim 1 , wherein the intermediate product, after said coating of the at least one surface, is coiled.
7 . The method according to claim 6 , wherein the flux and/or flux-producing compound comprises fluoride.
8 . The method according to claim 6 , wherein the resin comprises an acrylic acid ester.
9 . The method according to claim 6 , wherein the brazing composition comprises a wax selected from the group consisting of hydrocarbon wax, a polyolefin wax, and a mixture thereof.
10 . The method according to claim 1 , wherein the weight ratio of the flux and/or flux-producing compound to the resin is in a range of 1:2 to 6:1.
11 . The method according to claim 6 , wherein the weight ratio of the flux and/or flux-producing compound to the resin is in a range of 1:2 to 6:1.
12 . The method according to claim 1 , wherein the brazing composition further comprises a dispersion agent.
13 . The method according to claim 12 , wherein the weight ratio of the dispersion agent to the combined weight of the flux and/or flux-producing compound and resin and the wax is in a range of 0.2:99.8 to 10:90.
14 . The method according to claim 6 , wherein the brazing composition further comprises a dispersion agent.
15 . The method according to claim 6 , wherein the brazing composition further comprises a brazing alloy or a composition of metals producing a brazing alloy upon heating.
16 . The method according to claim 6 , wherein the weight ratio of the wax to the combined weight of the flux and/or flux-producing compound and resin is in a range of 1:99 to 30:70.
17 . A metal substrate, having at least one flat surface and being at least partially covered with a brazing composition comprising a resin, a wax, and a flux and/or flux-producing compound.
18 . The metal substrate of claim 17 , wherein the metal of the metal substrate is an aluminum alloy.