Process for joining two metallic workpieces as well as process for joining copper and aluminum

摘要

A method for joining a first metallic workpiece (12) and a second metallic workpiece (14) with different melting points and thermal conductivities, the method comprising: applying a first coating (16) to at least part of the first metallic workpiece (12), wherein the first coating (16) has been made of a material with a lower melting point than the material of the first metallic workpiece (12), positioning the first metallic workpiece (12) and the second metallic workpiece (14) in relation to one another so that at least a joint (18) is formed where the two metallic workpieces are to be connected, and welding the first metallic workpiece (12) to the second metallic workpiece (14) along the at least one joint (18) by means of an arc welding process that uses a welding wire (26 ) includes, so that the first metallic workpiece (12) is wetted and gel is soldered and the second metallic workpiece (14) is melted and welded along the at least one joint (18), the arc welding process a cyclical alternation of a first stage in which the welding wire (26) is supplied with an electric current when it is applied to the Workpieces is moved, and a second stage in which the electrical current is reduced and the welding wire (26) is moved away from the workpieces to produce a plurality of molten droplets (32) along the at least one joint (18) and segregating, wherein the molten droplets (32) are formed from the welding wire (26) in the first stage, further, prior to applying the first coating (16), applying a second coating (24) to the first metallic workpiece (12) at substantially the same location as the first coating (16), the second coating (24) being made of a material with a higher Melting point is established as the material of the first metallic workpiece (12).