Tribological performance of CrAlYN-based nanocomposite coatings

The incorporation of Y has been known to improve the oxidation resistance and thermal stability of Cr-based nitride hard coatings. This is especially important in high temperature engineering applications (e.g. > 1000°C). In particular, the tribological properties of Y-doped coatings are of significant interest. Hence, this project aims to study the tribological performance of CrAlYN hard coatings with varying Y-doped content. The coatings were deposited using HIPIMS PVD technique, and their chemical composition and mechanical properties were evaluated using EDS and nanoindentation respectively. XRD and SEM were used to evaluate the crystalline phases and fracture morphology respectively. Tribological properties, such as the friction coefficient and wear rate, were evaluated using a ball-on-disk tribometer at room temperature, where the counterface used was a 6-mm diameter Al2O3 ball. SEM and EDS were subsequently used to analyse the features of the wear track and element distribution across the wear track. Wear performance declined for the coatings with a higher Y content. On the other hand, the coatings with low to moderate Y content had comparable wear performance with the CrN and CrAlN coatings, with the promise of improved high temperature wear performance.Bachelor of Engineering (Aerospace Engineering