Electrochemical deposition and microstructural characterization of AlCrFeMnNi and AlCrCuFeMnNi high entropy alloy thin films

•AlCrFeMnNi and AlCrCuFeMnNi high entropy alloys were prepared by electrodeposition.•X-ray diffractometry analysis indicated that the as-deposited films were amorphous.•The annealed thin films presented body-centered-cubic solid solution structures.•The high entropy alloy coatings exhibited good adhesion to the substrate.•Results show that electrodeposition is promising for high-entropy alloys synthesis. Al–Cr–Fe–Mn–Ni and Al–Cr–Cu–Fe–Mn–Ni high entropy alloy thin films were prepared by potentiostatic electrodeposition and the microstructure of the deposits was investigated. The thin films were co-deposited in an electrolyte based on a DMF (N,N-dimethylformamide)-CH3CN (acetonitrile) organic compound. The energy dispersive spectrometry investigation (EDS) indicated that all the five respectively six elements were successfully co-deposited. The scanning electron microscopy (SEM) analysis revealed that the film consists of compact and uniform particles with particle sizes of 500nm to 4μm. The X-ray diffractometry (XRD) patterns indicated that the as-deposited thin films were amorphous. Body-centered-cubic (BCC) structures were identified by XRD after the films were annealed at various temperatures under inert Ar atmosphere. The alloys adhesion on the substrate was determined by the scratch-testing method, with higher values obtained for the Al–Cr–Cu–Fe–Mn–Ni alloy.