Evaluation on Dynamic Wetting in Flattening of Thermal Sprayed Particle

Main objective of this research is how we can evaluate the dynamic wetting in thermally sprayed particle onto the substrate surface. Compare to the static wetting, dynamic wetting means the wetting phenomenon in which both material movement in the splat and heat transfer from splat into substrate occur simultaneously. As it is so complicated, we havenft had proper evaluation method. In this study, wetting behavior of freely fallen metallic material was systematically observed onto several kinds of substrate materials. Actually, concrete values of the wetting angle of the splats with increase of the substrate temperature were measured. It was found that the contact angle changed transitionally with increase of the substrate temperature and corresponded well to the disk splat fraction ratio change of thermally sprayed particle on the substrate. From the result, it was indicated that flattening of thermal sprayed particle is dominated essentially by the dynamic wetting of the substrate by the sprayed particles.