Abstract: An improved process is provided for forming a zinc-base alloy coating on an aluminum alloy profile, such as a tube or microtube used in the assembling and brazing of a heat exchanger which is suitable for automotive applications. The process of the present invention is a continuous, high speed coating technique which can utilize aluminum alloy profiles on which an aluminum oxide layer is present. Accordingly, the present invention encompasses an operation by which the aluminum oxide layer is removed so as to enable the zinc-base alloy to metallurgically adhere to the surface of the aluminum alloy profile. The process of this invention also is capable of closely controlling the thickness of the zinc-base alloy coating, such that a sufficient but minimal amount of coating is present to furnish corrosion protection as well as provide sufficient filler metal for a subsequent soldering or low temperature brazing operation.

Abstract: A method of joining Al-members, includes providing at least one member with a thin coating layer of zinc/zinc alloy metal. Interface alloys of Al and Zn are melted and progressively formed from the Al-members with increasing temperature thereof in a brazing furnace.