Effect of the specific surface topography on surface wettability of chromium-based coatings

Abstract

Surfaces featuring hydrophobic behaviour are generally prepared by a wide spectrum of technologies featuring different process complexity (anodic oxidation, lithography, electrodepositing, etc.). The aim of the work was to use a relatively simple method of magnetron sputtering to prepare metallic hydrophobic surface. Chromium coatings were selected due to their high adhesion to steel and corrosion resistance while conserving certain level of hardness and ductility. The tested coatings included pure Cr and pure Cr with CrN interlayer. The resulting contact angle value of up to 111°has confirmed hydrophobic behaviour. The resulting surface morphology is formed by almost perfectly developed crystals in the shape of hexagonal pyramids providing a suitable surface roughness conditions for hydrophobicity.

Environmental Friendly Modification of the Superhydrophobic Surface for Iron-Based Amorphous Alloy Films and Their Magnetic Surface Effect

“…Because of their unique microstructure, excellent mechanical properties, and soft magnetic properties and having the advantages of high magnetic conductivity, high saturation magnetic sensitivity, low coercivity, low iron-loss value, and good thermal stability and corrosion resistance, iron-based amorphous alloy films are widely used as soft magnetic materials in the manufacture of transformers, sensors, , and other devices. − When iron-based amorphous alloy films are used as soft magnetic materials to make electronic and electrical devices, they need to be encapsulated with organic resin (such as epoxy resin). Therefore, it is very important to modify the surface of the films to improve their wettability to resin. , …”

“…One is the rougher surface with larger surface roughness and many defects, such as pores, which present weaker superhydrophobic characteristics than the other surface. The other is the smoother surface with lower surface roughness, fewer impurities, and stronger superhydrophobic characteristics than the rough surface. ,,, The surface of iron-based amorphous films is not only hydrophobic but also oleophobic …”

“…Therefore, it is very important to modify the surface of the films to improve their wettability to resin. 7,8 On the other hand, using the sensitive characteristics of the amorphous structure combined with the characteristics of film toughness, 9,10 high strength, and good magnetic performance, iron-based amorphous alloy films can be used as flexible film sensors to measure changes in magnetic signals, which has attracted great attention in wearable electronic devices, 11 electronic skin, food, clinical medicine, and industrial fields (such as complex surfaces). 12−16 Based on sensor domain applications, the study of the magnetic surface effects of films is a key problem.…”

“…The other is the smoother surface with lower surface roughness, fewer impurities, and stronger superhydrophobic characteristics than the rough surface. 7,8,17,18 The surface of iron-based amorphous films is not only hydrophobic but also oleophobic. 17 At present, the surface modification of iron-based amorphous alloy films is based on the rougher surface with weaker superhydrophobic characteristics, and the chemical conversion membranes are mainly prepared by the oxidation method.…”

“…Therefore, it is very important to modify the surface of the films to improve their wettability to resin. 7 , 8 …”