The effect of MEVVA ion implantation of Zr on the corrosion behaviour of PVD TiN coatings

The use of TiN coatings as corrosion barriers is limited by the presence of defects such as pin-holes. In this study Zr ions were implanted into PVD deposited TiN coatings at varying doses, to improve the corrosion resistance. The corrosion behaviour was assessed in saline environments using linear polarisation techniques and the corroded surface of the coatings characterised using XPS and SEM. Overall, ion implantation resulted in an increase in the coating's corrosion resistance. Protection was attributed to closure of existing pin-holes and the formation of various nitrides, oxides and oxynitrides of Ti and Zr.