Relationship Between Splat Morphology and Cohesion-Adhesion Strength of Coatings

This study investigates the relationship between splat morphology and adhesion strength in plasma sprayed coatings. The shape and size of the splats are examined and found to differ, in some cases significantly, depending on whether the splats are in the center or on the periphery of the spray pattern. Splats in the center of the pattern are formed by particles with higher temperature and velocity than those on the periphery and they tend to produce higher quality layers. In an experiment in which alumina layers are sprayed through a graphite slit filter, coating adhesion is shown to be superior, as expected. Paper includes a German-language abstract.