Electrochemical Corrosion Behaviour of ZrN Film in Various Corrosive Fluid

摘要

Recently, ZrN has been attracting interest for its excellent corrosion resistance, biocompatibility, high hardness, good lubricity and ductility. Although tribological study of ZrN coating has been carried out extensively, investigation related to corrosion of ZrN film is limited. In view of this and in view of possible applications of ZrN film in several engineering components, the present investigation has been undertaken to evaluate the corrosion response of ZrN film in seawater solution, Hank's solution, 0.5M H_2SO_4 solution and O.5M HCl solutions. Towards that purpose, potentiostatic, open circuit potential and potentiodynamic study of ZrN film deposited on plain carbon steel has been carried out in all these solutions. Results indicate that stable protective film is formed on the surface of ZrN coating in all these solution except 0.5M H_2SO_4 solution. The formation of protective film on ZrN coating is fastest in sea water solution and it is slowest in the Cl~- ions containing media, 0.5 MHCl. The corrosion current is highest for 0.5M H_2SO_4 acid solution and least for Hank's solution.