Understanding the Microstructural Evolution of High Entropy Alloy Coatings Manufactured by Atmospheric Plasma Spray Processing

•Complete characterization of AlCoCrFeNi atmospheric plasma sprayed coatings.•In-flight oxidation results in Al2O3, Cr2O3, spinels, residual unoxidized alloy phases.•Effect of particle size and position relative to plume core on splatting behavior.•Particles <5 µm near plume core melt and oxidize completely forming oxide splats.•Particles >15 µm near plume core melt completely with surface oxides and alloy splats.