Pulse electrodeposition of aluminium coatings from molten salt bath; effect of processing parameters on the coatings’ corrosion and wear behaviour

ABSTRACT In this study, Al coatings were pulse electrodeposited from a molten salt electrolyte onto copper substrates. The effects of applied peak current density, pulse current frequency and duty cycle on the morphology, microstructure, corrosion behaviour and tribological properties of the coatings were investigated by scanning electron microscopy, X-ray diffraction, potentiodynamic polarisation, electrochemical impedance spectroscopy and pin-on-disc wear test methods. The results showed that the changes in processing parameters changed the morphological and microstructural features of the resulting coatings, which in turn affected their corrosion and wear behaviours. Coatings with smoother surfaces, finer crystallite size and more compact morphologies that were electrodeposited at higher applied peak current density (up to 80 mA cm−2), higher pulse current frequency (up to 50 Hz) and higher duty cycle (up to 50%) exhibited more corrosion and wear resistance than the others.