Laser Cladding of CoCrCuFeNi and CoCrFeNi High-Entropy Alloys on DMR 249A Steel: Corrosion, Wear and Antibacterial Behaviour

Laser cladding of CoCrFeNi and CoCrCuFeNi high entropy alloys on DMR 249A steel has been performed, and microstructural evolution, corrosion, and antifouling characteristics of the base metal and cladded surfaces were studied. The results reveal that CoCrFeNi cladding has a smaller average length and width of grain size (108 ± 31 µm and 30 ± 14 µm, respectively) than that of CoCrCuFrNi (178 ± 58 μm and 22 ± 12 µm). An increase in hardness was observed in both the cladding surfaces as compared to that of the base metal. The surface hardness of the laser-cladded CoCrFeNi and CoCrCuFeNi surfaces was found to be 415 and 310 HV, respectively. CoCrCuFeNi has a better wear resistance (wear rate of 4.63 × 10–10 mm3/m) than that of the CoCrFeNi alloy and the substrate due to the formation of copper oxide layers, which was confirmed using X-ray photoelectron spectroscopy analysis. Better corrosion resistance was observed in CoCrCuFeNi (corrosion rate: 0.0086 mm/year) and CoCrFeNi (corrosion rate: 0.0071 mm/year) compared to that of DMR 249A. CoCrCuFeNi cladding also shows superior antibacterial properties in the marine environment compared to the CoCrFeNi cladding and substrate. Since the CoCrCuFeNi alloy has superior wear and anticorrosion and antibacterial properties, it may be a good candidate for marine applications.