Electrosynthesis and Evaluation of Homogeneous CoCrNi Medium-Entropy Alloys for Structural Applications

Medium-entropy alloys (MEAs) have received increasing attention for various applications due to their excellent properties. This work demonstrates a facile electrolysis method to directly prepare homogeneous CoCrNi MEAs from mixed metal oxide precursors in molten CaCl 2 . The obtained CoCrNi MEAs with typical face-centered cubic structure show nodular particle morphology. The influences of electrolytic parameters on the cathodic samples were investigated, and the results show that tunable phase composition and particle size of the samples can be achieved by controlling the electrolysis time and temperature. The electrolytic intermediate samples have been systematically characterized and analyzed, and the electrochemical synthesis mechanism of CoCrNi MEAs has been proposed, which typically involves electrochemical deoxidation and in-situ alloying processes. Additionally, the electrochemically synthesized CoCrNi MEAs has been processed into bulk CoCrNi MEAs to further investigate and evaluate their mechanical properties for possible structural applications. The as-synthesized CoCrNi MEA shows the comparable yield strength, tensile strength, fracture elongation, and hardness of 994 MPa, 1183 MPa, 14 pct, and 412 Hv, respectively, exhibiting an excellent engineering strength-ductility combination.