FVM and XCT Measurement of Surface Texture of Additively Manufactured Parts

Focus variation microscopy (FVM) and X-ray computed tomography (XCT) are two popular technologies employed to measure the surface texture of additively manufactured components. The impacts of various influence factors of these two measurement techniques on surface texture measurement are investigated, respectively. A two-stage surface registration program is developed to allow the accurate comparison of surface topographies measured by two instruments at the same location on the surface. The associated surface texture parameters Sa, Sq, Ssk, and Sku are also compared. The results indicate XCT can capture re-entrant features, while FVM can capture more details. However, XCT measurement is limited in its resolution and FVM measurement is restricted by the line-of-sight constraint. The surface parameters of two measurement techniques are closer in the cases where surface texture of the parts is higher.