Generalised and automated method for surface analysis of roughness and subsurface porosity using micro-computed tomography

Abstract

As additive manufacturing enables the production of intricate, high-value parts with functional integration, inspection is gaining importance to ensure safety for use. Since the surface quality of laser beam powder bed fusion parts has proven to be inherently inhomogeneous, the measured values are dependent on the measurement spot, making surface quality difficult to characterise using conventional methods. Combined with the fact that the complex shape of the parts potentially complicates measurements further, a new surface characterisation method is required to adequately capture the quality of additively manufactured parts on the entire surface. In this work, a novel method is proposed that is both capable of meeting the above requirements and additionally allows the correlation of the results with the process data and the evaluation of the near-surface porosity. At the same time, the local quality deviations can be visualised and roughness hotspots found and correlated with the process.