Ni-Mo coating production by electrowinning: operative condition influence on alloy composition and morphology

Abstract: Aims: Ni-Mo alloy coatings could represent a key material for several leading applications of engineering. Indeed these coatings present excellent physico-chemical characteristics such as magnetism, wear-resistance, heat-conductivity, and electrocatalytic properties. Observations: Ni-Mo alloys have been electrowon, with a pH 5.8 sulphate catholyte containing 40 g/l Ni and Mo in the range 1-4 g/l, sodium citrate and acetic acid, at temperature in the range 25-50°C and current density in the range 10-100 mA/cm2. Methods: A cell having cathodic and anodic compartment separated by a polypropylene membrane has been used. Result: The effect of molybdenum ion concentration in the electrolyte, temperature and current density on coating morphology and the Ni-Mo deposit adherence on steel substrate as well as Mo content of the produced binary alloys have been investigated.