Areal surface texture data extraction from X-ray computed tomography reconstructions of metal additively manufactured parts

- Extraction of quantitative areal surface texture data from XCT measurements of metal additively manufactured parts.
- Less than 2.5% difference for Sa between XCT and focus variation measurements.
- Discussion of XCT scaling and surface determination correction.
- ISO 25178-3 filtering and ISO 25178-2 parameter generation.
- Generation of data suitable for analysis with standard surface texture analysis software packages.

Many applications that exploit the manufacturing flexibility of additive manufacturing (AM) produce surfaces, primarily internal features, which cannot be measured using conventional contact or line-of-sight optical methods. This paper evaluates the capability of a novel technique to extract areal surface data from micro-focus X-ray computed tomography (XCT) from AM components and then generate surface parameter data per ISO 25178-2. This non-destructive evaluation of internal features has potential advantages during AM product research and commercial production. The data extracted from XCT is compared with data extracted using a focus variation instrument. A reference dimensional artefact is included in all XCT measurements to evaluate XCT surface determination performance and dimensional scaling accuracy. Selected areal parameters generated using the extraction technique are compared, including Sa, for which the nominal difference between the value obtained using XCT and used the focus variation method was less than 2.5%.