Structural, Mechanical, Tribological, and Electrochemical Behavior of Ti_1−xAl_xN Coatings Deposited by High-Power Impulse Magnetron Sputtering from a Single Ti/Al Target

This study aims to explore the effects of varying Al content on the structural, mechanical, tribological, and corrosion resistance properties of Ti_1−xAl_xN coatings. For this purpose, high power impulse magnetron sputtering deposition was performed on floating substrates using a Ti-Al compound target. The results indicate that the maximal solubility of Al in cubic single-phase Ti_1−xAl_xN is achieved at x = 0.53, resulting in a maximal hardness and Young’s modulus of 23.1 and 385.7 GPa, respectively, while the optimal adhesion strength and wear resistance were observed at x = 0.62. In addition, the coated steel surfaces exhibited significantly improved corrosion protection compared to the uncoated ones, and the effectiveness of this protection was found to be dependent on the Al content in the coatings. Furthermore, the corrosion resistance of Ti_1−xAl_xN coatings was found to be higher than that of TiN, as evidenced by electrochemical impedance spectroscopy analysis.