MODELING OF PARTICLES IMPACTING ON A RIGID SUBSTRATE UNDER PLASMA SPRAYING CONDITIONS

Finite-element methods have been applied for the spreading process of a ceramic liquid droplet impacting on a flat cold surface under plasma spraying conditions, The goals of the present investigation are to predict the geometrical form of the splat as a function of process parameters, such as initial temperature and velocity, and to follow the thermal field developing in the droplet up to solidification. A nonlinear finite-element procedure has been extended to model the complex physical phenomena involved in the impact process. The dynamic motion of the viscous melt in the drops as constrained by elastic surface tensions and in interaction with the developing contact with the target has been coupled to transient thermal phenomena to account for the solidification of the material. A model is used to study the impact of spherical particles of liquid ceramic of given temperature and velocity on a flat, cool rigid surface. The deformation of the splat geometry as well as the evolution of the thermal field within the splat are followed up to the final state and require adaptive discretization techniques, The proposed model can be used to correlate flattening degrees with the initial process parameters.