Investigation of the structural characterization of duplex coati̇ng: grown on AZ91 alloy by MAO/HiPIMS-PVD methods

In this study; MgO interlayer was grown on AZ91 alloy using by Micro Arc Oxidation (MAO) method and subsequently CrAlYN/CrYN gradient thin film was grown on MgO interlayer by using High Power Impact Magnetron Sputtering-Physical Vapor Deposition (HiPIMS-PVD) method. It was aimed to improve the surface properties of the AZ91 magnesium alloy. The effective coating parameters and levels used in both MAO and HiPIMS-PVD coating methods were optimized according to the Taguchi Experimental Design Method using the L4 experimental plan. Structural characterization of duplex coatings which grown on surface of AZ91 alloy by MAO/HiPIMS-PVD methods were analyzed with Scanning Electron Microscopy (SEM) Energy Dispersive Spectroscopy, X-Ray Spectrometry (XRD), Scratch Test Equipment and Surface Roughness Test Equipment. It has been determined that CrAlYN/CrYN gradient coatings grown on AZ91 alloy with duplex surface treatment optimized for adhesion both improve adhesion and removed mechanical mismatch. As a result of the obtained experiments, it was determined that the strength of adhesion increased approximately 14 times with duplex coating (MgO/CrAlYN/CrYN) compared to the CrAlYN/CrYN gradient coatings grown directly on the AZ91 substrate material.