Particle Ejection by Jetting and Related Effects in Impact Welding Processes
Jörg Bellmann,
Jörn Lueg-Althoff,
Benedikt Niessen,
Marcus Böhme,
Eugen Schumacher,
Eckhard Beyer,
Christoph Leyens,
A. Erman Tekkaya,
Peter Groche,
Martin Franz-Xaver Wagner,
Stefan Böhm
Affiliations
Jörg Bellmann
Institute of Manufacturing Science and Engineering, Technische Universität Dresden, George-Baehr-Str. 3c, 01062 Dresden, Germany
Jörn Lueg-Althoff
Institute of Forming Technology and Lightweight Components, TU Dortmund University, Baroper Str. 303, 44227 Dortmund, Germany
Benedikt Niessen
Institute for Production Engineering and Forming Machines—PtU, The Technical University (TU) of Darmstadt, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany
Marcus Böhme
Institute of Materials Science an Engineering, Chemnitz University of Technology, Erfenschlager Straße 73, 09125 Chemnitz, Germany
Eugen Schumacher
Department for Cutting and Joining Manufacturing Processes, The University of Kassel, Kurt-Wolters-Str. 3, 34125 Kassel, Germany
Eckhard Beyer
Institute of Manufacturing Science and Engineering, Technische Universität Dresden, George-Baehr-Str. 3c, 01062 Dresden, Germany
Institute of Forming Technology and Lightweight Components, TU Dortmund University, Baroper Str. 303, 44227 Dortmund, Germany
Peter Groche
Institute for Production Engineering and Forming Machines—PtU, The Technical University (TU) of Darmstadt, Otto-Berndt-Straße 2, 64287 Darmstadt, Germany
Martin Franz-Xaver Wagner
Institute of Materials Science an Engineering, Chemnitz University of Technology, Erfenschlager Straße 73, 09125 Chemnitz, Germany
Stefan Böhm
Department for Cutting and Joining Manufacturing Processes, The University of Kassel, Kurt-Wolters-Str. 3, 34125 Kassel, Germany
Collision welding processes are accompanied by the ejection of a metal jet, a cloud of particles (CoP), or both phenomena, respectively. The purpose of this study is to investigate the formation, the characteristics as well as the influence of the CoP on weld formation. Impact welding experiments on three different setups in normal ambient atmosphere and under vacuum-like conditions are performed and monitored using a high-speed camera, accompanied by long-term exposures, recordings of the emission spectrum, and an evaluation of the CoP interaction with witness pins made of different materials. It was found that the CoP formed during the collision of the joining partners is compressed by the closing joining gap and particularly at small collision angles it can reach temperatures sufficient to melt the surfaces to be joined. This effect was proved using a tracer material that is detectable on the witness pins after welding. The formation of the CoP is reduced with increasing yield strength of the material and the escape of the CoP is hindered with increasing surface roughness. Both effects make welding with low-impact velocities difficult, whereas weld formation is facilitated using smooth surfaces and a reduced ambient pressure under vacuum-like conditions. Furthermore, the absence of surrounding air eases the process observation since exothermic oxidation reactions and shock compression of the gas are avoided. This also enables an estimation of the temperature in the joining gap, which was found to be more than 5600 K under normal ambient pressure.
