Superhard Ti–Si–N coatings by a hybrid system of arc ion plating and sputtering techniques

A new method for Ti–Si–N hard coatings, a hybrid coating system of arc ion plating (AIP) and sputtering techniques is introduced in this paper. Deposition behavior and mechanical properties of Ti–Si–N by the hybrid coating technique were investigated in this work. The Ti–Si–N coating layers were deposited on SKD11 steel substrates using the hybrid system where TiN was deposited by AIP method while Si was incorporated by sputtering technique. By this method, very dense and adherent Ti–Si–N coating layers could be synthesized, and the coatings were characterized by a composite consisting of fine TiN crystallites and amorphous silicon nitride. The coating layer showed the maximum hardness of 45 GPa with a load of 25 g at the Si content of 7.7 at.%. Surface roughness of the Ti–Si–N coating layer decreased with increase of Si content. The friction coefficient of Ti–Si–N layers against steel was also dependent on the Si content.