Generalization of profile texture parameters for additively manufactured surfaces

Additive manufacturing technologies allow the production of highly complex parts. The surface topography of such parts often presents micro-scale and freeform-shaped re-entrant features. These features cannot be measured completely using optical or tactile techniques, without sectioning the sample. Therefore, X-ray computed tomography has recently started to be used for topographical measurement of additively manufactured surfaces, as it is capable of acquiring also re-entrant features of the surface when a sufficiently high spatial resolution is achieved. However, profile texture parameters described in the standard ISO 4287 are not suited to characterise the aforementioned profiles, due to the possible re-entrant features. This paper proposes a new definition of texture parameters optimised for additively manufactured surface profiles with the presence of re-entrant features, measured by means of X-ray computed tomography. (paper)