Measurement of additively manufactured freeform artefacts: The influence of surface texture on measurements carried out with optical techniques. (15th March 2023)

• Record Type: Journal Article
• Authors: Grazia Guerra, Maria; Lavecchia, Fulvio
• Is Part Of: Measurement. Volume 209(2023)
• Publication Date: 2023-03-15
• Subjects: Metrology for additive manufacturing -- Surface texture -- Optical measuring techniques -- Metrological filters -- High resolution mesh -- Freeform artefact; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2023.112540
• Languages: English
• ISSNs: 0263-2241

Abstract

Highlights: Use of a standard freeform geometry realized by two manufacturing techniques for assessing the surface texture influence on optical measurements. Surface texture affects measurement results when instruments characterized by different working principle and resolution are analysed. Filtering the obtained freeform mesh with an increasing cut-off decreased the differences between the measurements conducted with the measuring instruments involved, achieving more convergent results, within a range of deviations very close to the reference values obtained on the micro-milled artefact. Abstract: Quality control of additively manufactured parts is a crucial topic, since it includes the measurement of freeform geometries, i.e. lattice structures, and parts characterized by surface topographies several times more rough than conventional machining. Freeform surfaces and their related measurands can be effectively assessed via areal optical scanning techniques and X-ray-based systems, while it is still of great interest to evaluate the effect of the surface quality on their measuring performance. In this work, an experimental investigation about the influence of a typical additive manufacturing surface texture on optical measurements was conducted. As test object, the geometry of a standard freeform artefact developed by the NPL Institute was considered and it was realized by using a Material Extrusion Additive Manufacturing (MEX) technology and micro-milling. By comparing results coming from the two realized artefacts, it was possible to evaluate the influence of the AM surface texture on the conducted measurements.