Splat formation during plasma spraying for 8Â mol% yttria-stabilized zirconia droplets impacting on stainless steel substrate

In this paper, the formation of 8 mol% yttria-stabilized zirconia (8YSZ) droplet impacting on stainless substrate during SAPS and APS has been analyzed by numerical simulation and experiments. The objective of the study was to establish the predictable relationships between the coating properties and various parameters of plasma spraying process. A mathematic model of single droplet deposition process was developed, the influence of solidification was considered in the governing equations. The model considered the following factors: surface tension, thermal contact resistance between droplet and substrate, viscosity, impacting velocity, and temperature of droplet. Dimensionless number Reynolds number, Weber number, Ohnesorge number and Biot number were used to explain the phenomena of splashing. The critical values of triggering splashing were analyzed quantitatively for 8YSZ droplets. The numerical results agreed well with the experiment data.