Particle behavior and coating formation in the plasma spray process

Atmospheric pressure plasma spraying is widely used to produce coatings of high melting point ceramic and metallic materials. There has been considerable investigation on the underlying fundamentals of the plasma spray process in order to understand and further improve on the complex process. In particular, the complex relationship between the processing conditions (e.g., plasma gas flow rates, arc power, carrier gas and powder feedstock flow rates; to mention but a few) on the coating quality are often studied. These conditions affect the spatial distribution of plasma jet temperature, pressure and velocity which interact with the solid particles or molten droplets influencing their temperatures, velocities and trajectories. The deposited coating structure in turn depends on the spatial distribution of size, temperature, trajectory and velocity of the particles or droplets at impact on the substrate.Doctor of Philosophy (MPE