SURFACE-ROUGHNESS OF TIN COATING

Surfaces of steel samples were prepared by polishing and grinding. The basic roughness characteristics were measured on parallel lines separated from each other by 0.2 mm in two perpendicular directions. TiN coatings with different thicknesses were magnetron-sputtered on sample surfaces and the roughness was measured at the same sites as on substrates. The differences between the substrate and coating were evaluated by statistical methods. The larger the thickness, the larger the differences were obtained. This is in agreement with the comparison of the graphic records of the surface unevenness. The roughness is a function of the technological parameters as e.g. of the bias. Examples of the surface topography are presented and the suitable characteristics for coating surfaces evaluation are discussed.