Non-Wetting Nickel-Cerium Oxide Composite Coatings with Remarkable Wear Stability

Abstract

Engineered non-wetting surfaces inspired by biological species are of interest in the industry due to their potential applications such as water repelling, self-cleaning antiicing, anti-corrosion, anti-fouling, and low fluid drag surfaces. However, the adoption of non-wetting surfaces in large scale industrial applications has been hampered by synthesis techniques that are not easily scalable and the limited long term stability and wear robustness of these surfaces in service. In this study, we demonstrate a simple, low cost, and scalable electrochemical technique to produce robust composite coatings with tunable non-wetting properties. The composite coatings are composed of an ultra-fine grain nickel matrix with embedded hydrophobic cerium oxide ceramic particles. Comprehensive characterization, including wetting property measurements, electron microscopy, focused ion beam analysis, hardness measurements, and abrasive wear testing were performed to establish the structure-property relationships for these materials. The grain refinement of the nickel matrix contributes to the high hardness of the composites. As a result of the bimodal CeO₂ particle size, hierarchical roughness is present on the surface of the composite, leading to remarkable non-wetting properties, even after 720 m of abrasive wear.