Assessing Altered Coating Adhesion on Plasma‐Deoxidized Surfaces Under Oxygen‐Free Conditions

Titanium nitride (TiN) coatings are widely used as wear‐protection layers on cutting and forming tools due to their high hardness and chemical stability. However, the adhesion of TiN on substrates, such as silicon and steel (1.4301), can be insufficient for a given application. This study investigates the effect of atmospheric pressure plasma pretreatment on the adhesion behavior of TiN coatings. The surface modification is analyzed using confocal laser scanning microscopy after plasma treatment with argon (Ar) and argon/hydrogen (Ar/H ₂ ) gas mixtures. Subsequently, the samples are coated by reactive magnetron sputtering. Adhesion performance is evaluated by cross‐cut test, while X‐ray diffraction is employed to detect possible changes in the crystalline structure of the coatings. Plasma treatment deoxidizes and activates the surface, which enhances adhesion between coating and substrate. Ar/H ₂ plasma, in particular, significantly improves coating adhesion compared to untreated samples. These findings demonstrate that plasma–surface pretreatment improves coating durability and has the potential to extend tool lifetime in industrial applications.