Fragmentation behavior of Y2O3 suspension in axially fed suspension plasma spray

The fragmentation behavior of Y2O3 suspension has been investigated using an Axial III system with axial feeding as a function of primary droplet size of atomized suspension, solid content in the suspension, and size distributions of raw powders. The results showed that very severe fragmentation of the suspension occurred due to the interaction of axially fed suspension with the thermal plasma jet. The volume of deposited splats was almost the same as that of the individual Y2O3 particles of the raw materials regardless of the above experimental parameters used in this study. In addition, in this axial feeding in the Axial III system, based on a few assumptions, the diameters of the fragmented liquid droplets were estimated to be around 1.9 mu m, which was below the usual detection limit of the droplet size analyzer. In this regard, the size distributions of raw powders appear to have a direct interrelationship with splat size distribution and thus have an important implication in the microstructure development of the deposited coatings. (C) 2016 Elsevier B.V. All rights reserved.