Microstructures and properties of plasma sprayed FeAl/CeO2/ZrO2 nano-composite coating

Commercial FeAl powders and ZrO2 nano-particles as well as CeO2 additive were reconstituted into a novel multi-compositional feedstock powders via spray drying. The resulting feedstock powders were used to deposit FeAl/CeO2/ZrO2 nano-composite coating by plasma spraying on 1Cr18Ni9Ti stainless steel. An X-ray diffractometer (XRD), a scanning electron microscope equipped with an energy dispersive spectrometer (SEM/EDS), and a field emission scanning electron microscope equipped with an energy dispersive spectrometer (FESEM/EDS) were employed to characterize the microstructure of the as-prepared feedstock powders and nano-composite coating. At the same time, the mechanical properties and friction and wear behavior of the nano-composite coating and pure FeAl coating were comparatively evaluated by using a Vickers microindentation tester and ball-on-disk sliding wear tribotester, respectively. And the wear mechanisms for the two types of coatings are discussed in terms of their microstructure and mechanical properties. Results indicate that the nano-composite coating has a much higher hardness and fracture toughness as well as drastically increased wear resistance than pure FeAl coating, which could be mainly attributed to the reinforcing effect of ZrO2 nano-particles and partially attributed to the refining effect of CeO2 in the nano-composite coating.