The Feasibility of Producing CoCrFeMnNi High Entropy Alloy Coatings by Electrochemical Deposition Method and Its Characterization

High entropy alloys (HEAs) are commonly defined as alloys composed of 5 or more alloying elements and several particular HEA systems have the ability to form a mono-phase solid solution structure. Altogether there are many high entropy alloys with unique properties. The production of high entropy alloys has been carried out in two types of bulk and coatings; HEAs are usually prepared by physical methods that used for obtaining bulk materials. HEA coatings have been produced by various deposition methods. Electrochemical deposition is a low-cost alternative for the synthesis of high entropy alloy thin films, and less research has been done on this method. In the present study, CoCrFeMnNi high entropy alloy was produced by potentiostatic electrochemical deposition in a chlorine bath with DMF-CH3CN solvent. The effect of applying constant potentials at values ​​of 1, 2, 3, 4, 5 and 6 volts on the formation of a high entropy alloy with a solid solution structure FCC, composition and morphology was investigated. Microstructure and chemical composition are determined by X-ray diffraction for thin films (GXRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) are used to investigate the corrosion behavior. The results of the EDS analysis showed that the chemical composition changed with the change of each electrodeposition parameters, but in all states, the entropy of mixing around 12 JK-1mol-1 that was in the range of formation of high entropy alloys. The results of the GXRD analysis proved the formation of a solid solution structure with the simple FCC phase. Coating morphology in a constant potential coating was flat, non-cracked and compact.