INFLUENCE OF POST-LASER PROCESSING ON THE MECHANICAL AND TRIBOLOGICAL PROPERTIES OF PVD TiAlN COATINGS

Abstract

TiAlN-coated cemented carbide samples were treated using an Nd:YAG laser at different scanning speeds after the physical vapor deposition (PVD) process. The ball-on-disk wear tests in dry friction condition were performed to evaluate the tribological properties of the treated TiAlN coated samples sliding against AISI 316 stainless steel materials. Characterization tests such as instrumented nanoindentation hardness tests and variable depth scratch tests were also carried out to evaluate the mechanical properties as well as the coating adhesiveness of the PVD TiAlN coatings with additional laser treatments. Results showed that the post-laser processing with appropriate input parameters can significantly affect the coating adhesiveness and anti-adhesive wear properties. In this study, the moderate scanning speed (10[Formula: see text]mm/s) is most effective in minimizing the PVD coating defect, densifying the PVD coating and increasing the critical load of the coatings, resulting in a increase of 32% in critical load of the coatings. Meanwhile, specific attention was paid to the role of post-laser processing in the stable protective layer formation. The adhesion layer of steel materials shows its best adherence to the post-treated TiAlN coating surface in combination with a high mechanical stability, due to a synergistic effect of the improved coating/substrate adhesion and mechanical interlock.