Adhesion and growth of titanium nitride coating deposited on AISI 316L using cylindrical magnetron sputtering

This study explores the efficacy of plasma etching for AISI 316L stainless steel (SS), in improving the adhesion of titanium nitride (TiN) coatings. Due to the presence of an oxide layer on SS, as deposited TiN coatings typically exhibit poor adhesion. Here, varying duration of plasma etching was employed to assess TiN coating adherence to the SS. The TiN coatings were deposited onto the SS substrate via cylindrical magnetron sputtering technique. Surface roughness value of similar to 10 nm was obtained on SS post 60 minutes plasma etching compared to unetched SS sample similar to 4 nm which was evaluated using Atomic Force Microscopy. X ray Diffraction analysis of the TiN coating after plasma etching revealed a preferred growth of the TiN (111) phase. Adhesive strength of the TiN coating was assessed through scratch testing. Scanning electron Microscopy was employed to analyze the surface morphology of the TiN coating and its failure phenomena post scratch testing. A comparative analysis of TiN coatings on various plasma etched SS surfaces highlighted the direct influence of the surface condition on growth, surface morphology, and roughness. Notably, 60 minutes etching duration yielded the highest adhesion strength of 0.94 N for the TiN coating on SS, contributing to its enhanced corrosion resistance properties.