Induced electrodeposition of tungsten with nickel from acidic citrate electrolyte

Abstract

Induced electrodeposition of Ni–W alloys was carried out onto steel substrates from acidic citrate baths (pH 4.5) under different conditions of concentration of electrolyte, current density and temperature. Bright and highly adherent Ni–W deposits were successfully obtained with a relatively high cathodic current efficiency CCE (80–85%). The CCE increases greatly with increasing pH and Ni2+ ion content in the bath. The W% in the alloy deposits is in the range of 4–20 wt% depending on the operating condition. The W content in the deposit was found to increase with an increase in Ni2+ ion content, pH and temperature. The surface morphology was examined by scanning electron microscopy while the structure of the alloy was examined by X-ray diffraction analysis.