Effect of substrate bias voltage on corrosion of TiN/Ti multilayers deposited by magnetron sputtering

Austenitic stainless steel can be attack by localized corrosion in saline environments, such as seawater. TiN/Ti multilayers can improve the corrosion resistance of the stainless steel better than TiN monolayers, because the titanium layers improve the impermeability of TiN/Ti multilayers. In this work, 1.75–4.55 mm thick layers were deposited on to grounded or 100 V biased substrates of 304 stainless steel substrates by reactive magnetron sputtering. The corrosion resistance of the layers was studied by means of potentiodynamic polarization in 0.5 M NaCl solutions. It was found that the pitting corrosion resistance was dependent on the bias and period number of the multilayers.