Influence of metal vapor on plasma arc stability

• Applicant: Professor Dr.-Ing. Frank Vollertsen
• Subject Area: Production Automation and Assembly Technology
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 387755874

Increasing process efficiency is currently focused by scientific research of thermal joining processes like arc welding. For a couple of years processes are optimized, modified, and controlled. Many studies were focused on interaction between the arc and its boundary conditions e.g. additional processes or base materials. Up to now, effects of evaporated metal cannot be observed separately from the surface temperature. Even preheating of a substrate has an influence on the arc. The dominating mechanisms for influencing the arc cannot be identified definitely. In this research project mechanisms of arc formation and stabilization by metal vapor insertion are investigated. Stabilization potential of different steels and aluminum alloys will be investigated under the hypothesis that the conductivity of the arc depends on the alloying element of the inserted metal vapor. With the designated setup effects due to surface warming of the work piece can be avoided. Therefore, metal vapor is generated with a laser beam from an isolated substrate and inserted orthogonal to the arc process. Changes of the arc voltage will be monitored during this vapor inflow. With additional spectroscopic analysis an identification of ionized elements in the arc is possible.Aim of this project is to identify and to validate arc stabilizing mechanisms on plasma arc welding. Further, extended knowledge will be used for development of high speed processes with higher reliability using new stabilizing mechanisms.

• DFG Programme: Research Grants