Technical Note:Corrosion Behavior of Post-Deposition Polished Droplet-Embedded Arc Evaporated and Droplet-Free High Power Impulse Magnetron Sputtering/Direct Current Magnetron Sputtering Coatings

Abstract

In this study, the effect of metal-rich core of the droplets on the corrosion properties of TiN, CrN, and ZrN arc evaporated nitride coatings has been investigated and the corrosion properties of such coatings have been compared with droplet-free, highly dense coatings grown by combined high power impulse magnetron sputtering (HIPIMS) and direct current magnetron sputtering (DCMS) technique. An industrial size coating deposition system enabled with HIPIMS technology was used for the deposition of combined HIPIMS/DCMS coatings. The corrosion behavior of the coatings was studied by potentiodynamic polarization test (−1 V to +1 V) using 3.5% NaCl solution. Initially, as-deposited arc evaporated coatings with an exposed surface area of 1 cm2 were subjected to corrosion. Then, the coatings were gently polished to expose the metal-rich core of the droplets. Subsequently, fresh uncorroded area of the polished coating was subjected to corrosion with previously corroded area masked. It has been found that mechanic...