Micro-texturing of a WC–10Co–4Cr-Coated ASTM A479 Steel to Form a Super-Hydrophobic Surface

Abstract

Super-hydrophobic (SH) surfaces mostly motivated by the primordial surface designs considerably increase the life of the substrate. In the present work, effort has been made towards rational development of the SH surface on ASTM A479 steels substrates coated with WC–10Co–4Cr using high-velocity oxy-fuel. Distinct coating configurations have been investigated to analyse the effect of circular texturing patterns using nanosecond laser fibre texturing machine for the development of SH surfaces. Here, a freshly prepared solution of Hexafor 644-D/PFOA/Al2O3 nanoparticles was utilized for simple HVLP spraying and dip coating methods to formulate SH coatings on untextured and textured surfaces. The developed SH surfaces were characterized by field emission scanning electron microscope, X-ray diffraction, energy-dispersive spectroscopy and surface roughness tester. Water repellency of fabricated SH surfaces and its durability were studied by measuring the water contact angle (WCA), sliding angle, sandpaper abrasion test, tape peeling tests and water impact tests. All the configurations of the developed SH surfaces were found to be sustainable against the different wear tests performed during the study and exhibited excellent repellence to water and ink droplets. The highest WCA and sliding angle for textured and dip-coated SH surface (configuration—C 2.1) were found to be 162.6° and 10°, respectively. Further, it was found that during the sandpaper abrasion test, and the configuration corresponding to textured surfaces after thermal spray coating sustained super-hydrophobicity up to 30 cycles. Because of simple steps and the desired properties obtained by proposed methods, the coatings may be used for producing SH surfaces in apt industrial applications.