Hardness, Adhesion, and Wear Performance of Duplex Treatment Coatings of Nitride/TiAlZrN with Different Zr Target Currents

Abstract

The surface treatment, which includes first a thermal diffusion process, such as nitriding and then a physical vapor deposition coating process as the working layer, is called duplex treatment in the literature. In this study, the effects of the duplex treatment on the hardness, adhesion, and wear performance of TiAlZrN coatings on the hardened AISI H13 steel produced using the closed field unbalanced magnetron sputtering method with variable Zr target current (2 A, 3 A, and 5 A) were investigated. Within the scope of these investigations, scanning electron microscope, x-ray diffracrometer, optical microscope, optical profilometer, energy-dispersive spectrometer, micro- and nano-hardness, scratch, and wear tests were used. In micro- and nano-hardness tests, it was determined that the hardness of the substrate increased significantly (approximately 400%) owing to the duplex treatment. In addition, with the increase in the Zr target current, it was observed that the hardness of the coatings was in an increasing trend. Adhesion strength increased with the enhancement of both the hardness of the substrate and the coatings. It was beheld that the adhesion strength of the coatings increased with the duplex treatment. Besides, the coating produced using the highest Zr target current reached maximum adhesion strength of 79 N in relation to superior hardness. Wear performance of the samples was determined using a ball-on-disk tribometer. As a result of wear tests, TiAlZrN coatings with duplex treatment were observed to notably improve the wear performance of the substrate material by 95 times. The effects of Zr target current on the wear performance of the coatings were similar to those of hardness and adhesion strength.