Wear and Corrosion Protection of Interstitial Free Steel by Sputter Deposition of Alloy Coating as a Novel Alternative to Galvanizing

The present study explores the feasibility of sputter deposition of two Sn-rich Sn(Zn) alloy coatings (Sn-8.8 wt.% Zn and Sn-30 wt.% Zn) using single or identical twin jet magnetron sputtering for improving surface mechanical and corrosion properties of interstitial free steel. The thickness, average grain size and hardness of the deposit varied with the target composition and deposition parameters. Detailed studies reveal that coating deposited from a single pre-alloyed (Sn-30Zn) target offered the most attractive combination of the highest hardness (HV0.01 175 ± 6) and improvement in wear and corrosion resistance. However, the highest corrosion resistance in terms of higher or more active corrosion potential was obtained when sputter deposition was made from twin targets of Sn-8.8Zn. The results indicate that Sn-rich Sn(Zn) alloy may reduce or even substitute total dependence on pure Zn coating (i.e., galvanizing) for corrosion and scratch protection of steel.