Electron beam welding of copper using plasma spraying for filler metal deposition

Due to physical properties like high thermal and electrical conductivity, joining of copper is of special interest in steelmaking or electrical industry. Unfortunately, joining of thick-walled copper components using electron beam welding (EBW) tends to welding defects like insufficient root formation or varying penetration depth. In previous investigations, Cu-DHP (deoxidised high phosphorus copper) plates were successfully joined by EBW utilising a CuSn6 sheet as filler material. The investigation resulted in a stable EBW parameter window. Nevertheless, using CuSn6 sheets lead to challenges concerning joint preparations, and is not usable for arbitrary weld configurations. To meet these challenges, atmospheric plasma spraying (APS) is used to apply a thin interlayer in the welding zone and substitute the CuSn6 sheet filler metal. This continuative work includes further improvements of the main EBW parameters and uses APS as a new approach for filler metal deposition. Furthermore, determining and enhancing the service properties of the copper joints is of main interest and reported here.