Mechanical characteristics and electrochemical behaviour of electrodeposited nanocrystalline iron and iron-nickel alloy

Interstitial free (IF) steel exhibits high formability but relatively lower strength and poor wear resistance, whereas nanocrystalline materials provide excellent mechanical properties due to their high grain boundary area. The present study is aimed at amalgamation of nanocrystalline materials to IF steels in the form of hard coatings to assess the wear and corrosion resistance. Nanocrystalline Fe and Fe-Ni alloy, with grain size of similar to 25 nm, produced by pulsed electrodeposition were used to investigate micro-wear and electrochemical behaviour. As compared to IF steel, nanocrystalline Fe and Fe-Ni showed nearly five-fold increase in hardness and 50% reduction in wear volume loss. Higher corrosion rates of nano crystalline Fe are kinetically favoured due to high grain boundary region and lack of passive film formation. Alloy deposition of nanocrystalline Fe with Ni (similar to 2.6 wt.%) has proved to be beneficial for improving corrosion resistance without substantial compromise in its wear resistance. (C) 2017 Elsevier B.V. All rights reserved.