Insights into the compatibility of a metastable FeMnCoCr high entropy alloy with a Fe-based shape memory alloy

High entropy alloys (HEA) are novel advanced materials that have been subjected to extensive research due to their outstanding properties and potential for key engineering applications. Given this, research on their processability must be conducted to avoid premature failure during operation. Gas tungsten arc welding is a widely available technology capable of generating high performing and permanent joints. Furthermore, within this technology, dissimilar welding is a relevant topic given the frequent necessity to join different materials, allowing for greater design freedom while decreasing material costs. In this study, dissimilar welding of a FeMnCoCr HEA with a Fe-based shape memory alloy was conducted, allowing an inquiry into the compatibility between the two advanced engineering alloys. By employing both conventional and advanced characterization techniques, including optical and electron microscopy, atom probe tomography and synchrotron x-ray diffraction, a comprehensive understanding of the effect of processing condition on the microstructure and mechanical response of the joints is obtained. With this work we intend to highlight a pathway for the introduction of HEAs in modern day engineering industry. • Dissimilar welding between a FeMnCoCr HEA and a Fe-based SMA was successfully performed to assess their compatibility for key engineering applications. • Advanced characterization techniques revealed how arc-welding drives microstructure and performance, offering key insights for deploying high-entropy alloys in engineering applications. • Mechanical testing showed that the joints sustained up to 671 MPa and ~15.5% elongation before failure, demonstrating strong performance for a dissimilar weld.