Characterisation of additively manufactured metal surfaces by means of X-ray computed tomography and generalised surface texture parameters

X-ray computed tomography (CT) has recently started to be used for evaluating the surface topography of metal parts produced by additive manufacturing (AM). In particular, CT can overcome the main limitations of contact and optical measuring techniques, as CT enables non-destructive measurements of both internal and difficult-to-access surfaces, including micro-scale re-entrant surface features. This work aims at improving the understanding of CT-based surface topography characterisation, including the use of new generalised surface texture parameters suited for AM surfaces. Experimental investigations are performed on Ti6Al4V reference samples fabricated by laser powder bed fusion to determine the uncertainty of CT surface topography measurements.