TY - CONF A1 - Richter, Tim A1 - Erxleben, Kjell A1 - Rhode, Michael A1 - Schröpfer, Dirk T1 - Weldability of dissimilar metal welds of innovative high and medium entropy alloys to austenitic stainless steels joint by tungsten inert gas and friction stir welding N2 - The new multi-element alloying concept of systems with defined entropy (HEA - High Entropy Alloy or MEA - Medium Entropy Alloy) is increasing in materials research interest. Improved properties or combinations of properties are shown by several systems. Thus, the resulting microstructures and production of HEA/MEA as well as properties have been primarily investigated so far. Furthermore, processing is a key issue to transfer HEA/MEA systems to real components. Since welding is the most important joining process for metals, it is crucial to investigate the influence of welding to guarantee component integrity. Since most HEA are made of expensive alloying elements such as Co or Ni, they will not be used entirely as structural materials. Thus, it can be advantageous to weld conventional alloys such as austenitic stainless steels with the HEA and MEA to produce components that are both application-oriented and economically viable. Therefore, in this paper, first results of dissimilar metal welding, by tungsten inert gas- (TIG) and friction stir welding (FSW), of a CoCrFeMnNi HEA as well as a CoCrNi MEA with a conventional AISI 304 austenitic stainless steel are presented. The focus is on the microstructure formation due to the two welding processes. The results of TIG welding show a dendritic microstructure, whereas in FSW both materials are stirred but still coexist. T2 - 75th IIW Annual Assembly CY - Tokyo, Japan DA - 17.07.2022 KW - High Entropy Alloy KW - Medium Entropy Alloys KW - Welding microstructure PY - 2022 AN - OPUS4-55442 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Tim A1 - Schröpfer, Dirk A1 - Rhode, Michael T1 - Residual stresses in near-component specimens of a high and a medium entropy alloy due to tig and friction stir welding N2 - The new alloying concept of multi-element systems with defined entropy (HEA - High Entropy Alloy or MEA - Medium Entropy Alloy) is gaining increasing importance in materials research. Significantly improved properties or combinations of properties are shown by some HEA/MEA-systems. Thus, primarily the production and resulting microstructures of HEA as well as properties have been investigated so far. Furthermore, processing is a main issue to transfer HEA systems from the laboratory to real components. Since welding is the most important joining process for metals, it is crucial to investigate the influence of welding to guarantee component integrity. Welding leads to residual stresses, which significantly affect the component integrity. Hence, the focus of this study is the residual stress formation and distribution in a CoCrFeMnNi HEA and ternary CoCrNi MEA using two different welding processes: Tungsten Inert Gas (TIG) welding and soldi-state Friction Stir Welding (FSW). As a pathway for application of HEA in this investigation for the first-time residual stress analyses in realistic near-component specimens were performed. The residual stresses were determined by X-ray diffraction (XRD) on the surfaces of top and root weld side. The results were correlated with the local welding microstructures. The results show that both FSW and TIG generate significant tensile residual stresses on the weld surfaces in and transverse to the welding direction. In the case of FSW of the CoCrFeMnNi HEA, the longitudinal residual stresses are in the range of the yield strength of approx. 300 MPa in the weld zone. T2 - ICRS11 – 11th International Conference on Residual Stresses CY - Nancy, France DA - 27.03.2022 KW - High Entropy Alloy KW - Medium Entropy Alloys KW - Welding microstructure KW - Residual stresses PY - 2022 AN - OPUS4-55444 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -