Nanocrystalline cobalt–iron alloy: Synthesis and characterization

Nanocrystalline cobalt–iron (CoFe) alloys were electrodeposited from a sulfate bath by direct current. The bath temperature and pH was maintained at 40 °C and 2.5 respectively. The iron content was varied to study the effect on the surface morphology, grain size, current efficiency and microhardness. The experimental results showed that grain size of the CoFe alloy coating decreased with an increase in the iron content from about 6–25 wt%. Nanocrystalline CoFe coatings with an average grain size of 15 nm were achieved in coatings with 25 wt% Fe. Furthermore, the nanocrystalline CoFe coating was roughly three times harder than pure polycrystalline cobalt.