Abrasive wear behavior of nano-ceria modified NiCoCrAlY coatings deposited by the high-velocity oxy-fuel process

Abstract

In this study, the as-received and nano-ceria modified NiCoCrAlY coatings were deposited by the high-velocity oxy-fuel spraying (HVOF) process. The various mixture ratios of ceria nanoparticles (0.5, 1.0 and 2.0 wt%) were chosen for the development of modified coatings. Microstructural investigations for the conventional and modified coatings were carried out using a field-emission scanning electron microscope (FESEM) and x-ray diffraction (XRD) analysis. Moreover, the adhesive strength, the fracture toughness, and the abrasive wear behavior of nano-ceria modified NiCoCrAlY coatings were examined and compared to the original NiCoCrAlY coating. The obtained results demonstrated that, the modified NiCoCrAlY-1.0 wt% nano-ceria coating represented a relatively denser structure owing to lower amounts of porosity and oxide compared to other types of as-received and modified NiCoCrAlY coatings. Results also indicated that the indentation fracture toughness of nano-ceria modified coatings up to 1.0 wt% accordingly increased. The modified NiCoCrAlY-1.0 wt% coating had a higher bond strength compared to other types of as-received and modified coatings. In addition, the modified NiCoCrAlY-1.0 wt% nano-ceria coating also had better abrasive wear resistance due to its higher microhardness and desirable dispersion of nano-ceria reinforcement in the layer of coating.