Electrodeposition and wear behavior of NiCoW ternary alloy coatings reinforced by Al2O3 nanoparticles: Influence of current density and electrolyte composition

Al2O3 nanoparticles incorporated NiCoW ternary alloy coatings were synthesized by direct current electrodeposition from sulphate-citrate electrolyte. The influence of applied current density and electrolyte composition on the evolution of surface morphology, element composition, microstructure, microhardness and sliding wear behavior of the as-deposited coatings was investigated. The as-deposited coatings exhibit colony surface morphology and the inter-colony boundaries lead a leaf vein-like cross-sectional structure. The composition of the as-deposited coatings is controlled by the induced co-deposition mechanism and the competition among the reductions of Ni, Co, Ni-W and Co-W. The as-deposited coatings change from crystalline to amorphous structure with the decrease of Ni content in coatings and the critical Ni content for the transformation is about 40 at.%. The incorporation of Al2O3 nanoparticles leads to a little increase of microhardness, degrades adhesive wear and oxidation wear, then significantly improve wear resistance. Variations in electrodeposition conditions lead the as-deposited coatings with different wear behavior, including abrasive wear, adhesive wear and oxidation wear, accompanying with plastic deformation. An attempt is made to establish the relationship between the electrodeposition conditions and wear behavior. [Display omitted] •Al2O3 reinforced NiCoW ternary alloy coatings were prepared by DC electrodeposition.•Electrodeposition mechanism of NiCoW/Al2O3 composites is discussed.•Al2O3 nanoparticles could degrade adhesive wear and oxidation wear of NiCoW coatings.•Relationship between electrodeposition conditions and wear behavior is established.