Product Code: PIC06_506

Flux Free Joining of Zinc Coated Steel as Well as Steel/Aluminum through Laser and Controlled Short Arc Technology
Authors:
Johannes Wilden, Technical University Ilmenau; Neuhaus 1 Germany
Jean Pierre Bergmann, Institute for Production Engineering, Technical University Ilmenau; Ilmenau Germany
Markus Dolles, Institute for Production Engineering, Technical University Ilmenau; Ilmenau Germany
Sven-F. Goecke, Institute for Production Engineering, Technical University Ilmenau; Ilmenau Germany
Presented at PICALO 2006

The steady development of short arc technology offers the unique chance to join metallic materials with minimized heat input. Due to the high dynamic electronic regulation of the welding current, overheating of the melt pool while the material is transferred can be avoided. Especially for welding of very thin sheets and for joining of materials coated with low melting alloys the new process offers several benefits. Moreover this technology allows using filler material with a low melting point, e.g. zinc alloys, as boiling can be limited and eruption of liquid metal from the melt bath due to the vaporization of zinc avoided. In the case of joining of material combinations, where one joining partner is characterized from a high melting oxide layers, e.g. aluminum, the wetting of the gap causes problems and a deep and wide bonding area can't be guaranteed. The use of conventional fluxes represents a solution, which isn't accepted in all industrial application, as corrosive residue has to be removed by a following pickling process. In this paper a combination of a controlled short arc technology with a leading laser beam treatment is reported. Moreover the resulting process and joining properties for the dissimilar material combination steel/aluminum are shown. The task of the laser beam, which moves in front of the arc, is the destruction and removement of the oxide layer on the aluminium side. Consequently a wetting of the aluminum surface through the controlled arc melt pool is possible. This contribution shows the fundamental investigations for the use of the process combination. Especially instructions, cognitions and the mechanic-technological properties of the soldered joints are given.