Tribological performance assessment of Al2O3-YSZ composite coatings deposited by hybrid powder-suspension plasma spraying

Artikel i vetenskaplig tidskrift, 2021

The advent of high-throughput plasma spray systems that allow axial feeding encourages the study of using
liquid feedstock for various next-generation functional applications. The current study explores the benefit of
such a plasma spray system to deposit hybrid powder-suspension Al2O3-YSZ ceramic matrix composite (CMC)
coatings for tribological applications. The tribological performance of the hybrid processed CMC coatings was
assessed using scratch, ball-on-plate wear and erosion tests and compared with that of monolithic powderderived
Al2O3 coatings. As-deposited and tribo-tested coatings were characterized using Scanning Electron Microscopy,
X-ray Diffraction and Energy Dispersive Spectroscopy to analyse their microstructure and phase
constitution. The results showed that the tribological performance of the hybrid powder-suspension Al2O3-YSZ
CMC coating was significantly improved by enhancing the wear resistance under scratch, dry sliding ball-onplate
and erosion tests as compared to the conventional APS deposited monolithic Al2O3 coating. About 36%
decrease in the dry sliding ball-on-plate specific wear rate and up to 50% decrease in the erosion wear rate was
noted in the hybrid powder-suspension Al2O3-YSZ CMC coating as compared to the conventional APS deposited
monolithic Al2O3 coating. The study concludes that the hybrid powder-suspension route can create CMC coatings
with unique multi-length scale microstructures which can be attractive for combining different tribological attributes
in the same coating system.