ИСТИНА

Fe49Mn30Cr10Co10C1 high entropy alloy (HEA) is produced by induction melting. The as-cast alloy is cold rolled and annealed at 900°C, to produce fine recrystallized structure before friction stir welding (FSW). The structure of the annealed alloy consists of a recrystallized face-centered cubic (fcc, γ) and hexagonal close-packed (hcp, ε) phases with volume fractions of 91% and 5%, respectively, as well as M23C6 carbides with the volume fraction of 4%. Sound weld without visible defects, such as porosity or cracks, are obtained. Friction stir welding results in a decrease in the average grain size from 7.0 to 1.9 μm in the stir zone. The volume fraction of the M23C6 carbides decreases to 1% after FSW. The alloy shows high yield strength and ultimate tensile strength of 475 MPa and 865 MPa, respectively, together with elongation of 70%.