Electrodeposition of multilayer Ni–W and Ni–W–alumina nanocomposite coatings

Abstract

Multilayer Ni-W and Ni-W-Al 2 O 3 coatings with intermittent low and high concentrations of tungsten and alumina were electrodeposited through alternative variation of pulse parameters. Microstructural studies and elemental analyses of the coatings were carried out using scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Profilometry and atomic force microscopy were employed to investigate the surface roughness at two different scales. Pin-on-disc wear test was used to evaluate the tribological properties. The corrosion resistance was also studied using potentiodynamic polarisation and electrochemical impedance spectroscopy methods. Results revealed that at lower duty cycles, more incorporation of alumina and more co-deposition of tungsten are achieved. Results indicated variable and alternative microhardness values corresponding to the different concentrations of tungsten and alumina in each specific layers. Wear tests demonstrated the descending trend of the wear rate as a function of sliding distance. It was found that alumina nanoparticles enhanced the corrosion resistance.

Effect of SiC particle size and heat-treatment on microhardness and corrosion resistance of NiP electrodeposited coatings

“…It was also reported by Shafiee et al [22] that nanocomposite modulated multilayer coatings (Ni/Ni-Al2O3) can be a possible alternative to single layer nanocomposite coatings in tribological applications. Multilayer Ni-W and Ni-W-Al2O3 coatings were exhibited as a proper candidate for corrosion and wear resistant coatings [23]. However, increasing tungsten in the Ni-W coatings which improves wear resistance, can increase possibility of surface cracking and lead to poor corrosion resistance.…”

Substantial electrode life enhancement in resistance spot welding of galvanised steels through nanolayered multi-layer CrN/(Cr,Al)N coating

“…However, the electrode degradation mechanism has been less studied in detail, calling for more investigations. Moreover, the previous studies have focused on single-layer coatings, while multi-layer coatings have many advantages over their single-layer counterparts, such as high strength [18-22], greater adhesion [22,23], less residual stress[24], better mechanical and typological properties [23,25-32], and more desirable corrosion resistance [20].…”

Effect of Al2O3 Nanoparticles and Heat Treatment on the Wear Resistance of Electrodeposited Ni-W/Al2O3 Composite Coatings

“…Al 2 O 3 nanoparticles have superior properties, such as good chemical stability and excellent mechanical properties, and then have been most commonly applied as reinforced phase in electrodeposited Ni-W composites ( Ref 12,[16][17][18][19]. The Ni-W/ Al 2 O 3 composite coatings can be prepared by direct current or pulse electrodeposition (Ref 12,16), and the Ni-W matrix can be nanocrystalline or amorphous according to the electrodeposition conditions (Ref 17).…”