Enhancement of Tensile Properties Applying Phase Separation with Cu Addition in Gas Tungsten Arc Welds of CoCrFeMnNi High Entropy Alloys

This study investigates the gas tungsten arc weldability of the high-entropy alloy CoCrFeMnNi using CoCrFeMnNi and CuCrFeMnNi fillers. The CoCrFeMnNi-based weld had the same face-centered cubic (FCC) structure as the base metal, and the CuCrFeMnNi-based weld exhibited phase separation of the Cu-rich phase in addition to the FCC structure. Although the grain size of the CuCrFMnNi-based weld was similar to that of the CoCrFeMnNi-based weld, the Cu-rich phase formed in the CuCrFMnNi-based weld enhanced its tensile properties. This occurred because the dislocation movement and slip band in the weld metal were hindered by the formation of the Cu-rich phase.