Enhancement of electrochemical surface properties in steel substrates using plasma-sprayed coatings

Ceramic coatings are applied on various engineering hardware components to provide protection against wear, corrosion and high heat fluxes. Metal hardware operating in harsh environments could fail prematurely due to wear, corrosion and high temperature exposure. A protective layer of coating is typically applied to provide a barrier which prolongs component durability and the desired properties of the hardware components. Improvement of corrosion properties on stainless steel surfaces coated with partially stabilised zirconia and zirconia ceria deposited by plasma spraying has been studied in this work. The coated specimens were studied in terms of Tafel polarisation curves and electrochemical impedance spectroscopy. The best behavior was obtained by the zirconia ceria powder coating, showing the maximum corrosion resistance (polarisation resistance of 335.0 KΩ, and corrosion rate of 0.002 mm/y). Those results indicated an improvement of anticorrosive properties, compared to the zirconia ceria system with partially stabilised zirconia. © 2015 Taylor & Francis.