Copper brazed directly Problems

Direct Copper brazing mainly two: the need to use corrosive aluminum brazing agent to remove the oxide film, moisture absorption flux residues form an electrolyte constituting the strong corrosive; aluminum, copper atoms diffuse faster, easier plastic Hydraulic adaptersconnector in the package forming fusible eutectic brittle, leading to joint strength is low, and the electrode potential than the electrode potential is high, prone to intergranular corrosion. Thus, aluminum and copper is generally believed that direct brazing is difficult. In order to prevent oxidation of solder joints, preferably in an inert atmosphere, the production of furnace, heating by hydraulic hose fittingresistance heating or flame brazing.
In order to avoid the formation of aluminum and copper brittle compounds, aluminum and copper atoms necessary to avoid direct contact, and to avoid corrosive flux caused by corrosion problems, can be coated on the surface layer of metal (such as nickel), and then with Brazed , to avoid the formation of aluminum and copper brittle compound, but also can be used corrosive or non-corrosive flux, thus increasing the joint strength and corrosion resistance.