Characterization of Cr/CrN nano multilayers obtained through reactive sputtering with different degrees of unbalance in the magnetron

Abstract

Nanoscale hard coatings of bilayers of Cr/CrN were obtained and characterized through unbalanced magnetron sputtering (UBMS) in an atmosphere of Ar and Ar + N2 on silicon and hardened and tempered H13 steel, with a degree of unbalanced K0 between 0.87 and 1.37. The deposition parameters were as follows: a power of 160 watts, Ar and N2 flow rates of 9 and 3 sccm, and a substrate target distance of 5 cm. A Gen coa VT 100 magnetron with varying degrees of unbalance, obtained by displacing its central magnet, was used. The electrochemical behavior of these coatings was characterized using the technique of potentiodynamic anodic polarization. The coatings' microstructure and hardness were analyzed via X-ray diffraction (XRD) and nanoindentation tests; Cr, CrN, and Cr2N phases were obtained, with a hardness that increases with the degree of unbalance between 18.90 and 24.97 GPa.