ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Ni-W alloy coatings deposited from a citrate electrolyte

Matilda Zemanová, Robert Kurinec, Vladimír Jorík, and Magdaléna Kadlečíová

Faculty of Chemical and Food Technology Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia

E-mail: matilda.zemanova@stuba.sk

Abstract: Ni-W alloy coatings were deposited by applying current pulses with different pulse parameters at 60°C onto mild steel substrates from aqueous electrolytes with different tungstate concentration. Morphology and composition of the alloys were analyzed by SEM and EDX, respectively. XRD was used to determine metallic phases. Scanning electron micrographs revealed that deposition parameters had a strong effect on the morphology of the coatings. Increasing the duty cycle or decreasing the off time led to a compact morphology. Corrosion properties of the coatings were investigated by potentiodynamic polarization in a chloride medium. It was found that compact morphology of the deposits and high content of tungsten in the coating contribute to satisfactory corrosion results of Ni-W alloy coatings under the conditions studied.

Keywords: Ni-W alloy coating – pulse plating – morphology – potentiodynamic polarization

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-011-0116-0

Chemical Papers 66 (5) 492–501 (2012)