A definition of the topography of grit-blasted surfaces for plasma sprayedalumina coatings

This paper describes the topographical implications of grit blasted surface s on plasma sprayed alumina. The transition of the grit blasted surface fro m raw material to correctly blasted is described in terms of surface height s, height distribution, spacings and texture. The influence of embedded gri t is shown to be significant. The individual particles of alumina impacting the surface are classified into two types, these being disc splats and spl ash splats. Their deposition relationships with regard to surface topograph y and adhesion is explained with reference to the two types of splat.