Erosion-corrosion of electrodeposited superhydrophobic Ni-Al₂O₃ nanocomposite coatings under jet saline-sand slurry impingement

For the first time, this study developed a detailed insight into the correlation between superhydrophobicity, erosion-corrosion resistance, and reinforcing phase amounts of Ni-Al₂O₃ nanocomposite coatings electrodeposited on Cu. Erosion-corrosion was electrochemically investigated at a 90° impact angle via a jet-impingement slurry erosion setup with erodent particles primarily under 100 µm. The preferred crystallographic growth orientation was along (220). No synergy emerged between superhydrophobicity and erosion-corrosion resistance. Ni-(2.9 wt%) Al₂O₃ resistance to erosion-corrosion outperformed Ni-(0, 2.0, 2.4 wt%) Al₂O₃. Depend on the duration of slurry exposure, either kinetic or a mixed kinetic and diffusion control mechanism was predominant at the OCP.