Electrodeposition of Ni-W-B nanocomposite from tartrate electrolyte as alternative to chromium plating

The effect of the bath chemistry and operating conditions on the chemical composition, microstructure and properties of Ni-W-B alloys deposited from tartrate baths on working electrode was studied for the first time by the pulsed current method. The investigations included the measurement of the current efficiencies and determination of the tungsten content in the electrodeposits. UV spectrometry was used for characterisation of complex formation. The grain size of deposits was determined by XRD. Also, the morphology of the deposits was studied by SEM. Amorphous Ni-W-B alloys were successfully obtained by electrodeposition from the tartrate bath. The corrosion behaviour of Ni-W-B coating on mild steel has been evaluated during exposure to 3.5% NaCl solution by electrochemical impedance spectroscopy. The electrochemical and corrosion behaviour of Ni-W-B alloy showed a good corrosion resistance in the 3.5% NaCl medium. The microhardness of nanocrystaline Ni-W-B is in the range between 700 and 850 HV.