Corrosion and Wear-Resistant Composite Zirconium Nitride Layers Produced on the AZ91D Magnesium Alloy in Hybrid Process Using Hydrothermal Treatment

Abstract

The aim of the study was to investigate the possibility of an effective improvement in performance properties, including corrosion and wear resistance of magnesium AZ91D alloy using a surface engineering solution based on zirconium nitride composite surface layers produced on AZ91D alloy in a hybrid process using hydrothermal final sealing. Research results show that the formation of a composite ZrN-Zr-Al-type zirconium nitride layer on zirconium and aluminum sublayers results in a significant increase in resistance to corrosion and wear. The decrease in chemical activity of the sealed zirconium nitride composite layer on AZ91D, expressed by the displacement of the corrosion potential in the potentiodynamic test, reaches an outstanding value of ΔEcorr = 865 mV. The results of the SIMS chemical composition analysis of the layers indicate that the sealing of the composite layer occurs at the level of the aluminum sublayer. The composite layer reduces wear in the Amsler roll on block test by more than an order of magnitude. The possibility of effective sealing of zirconium nitride layers on the AZ91D alloy demonstrated in this study, radically increases the corrosion resistance and combined with the simultaneous mechanical durability of the layers, is of key importance from the point of view of new perspectives for application in practice.

Keywords

• magnesium alloys
• zirconium nitride
• composite layers
• hybrid process
• hydrothermal treatment
• corrosion resistance