Additive Manufacturing (AM) of metals is rapidly emerging as an innovative production technology. Nevertheless, the quality of metal AM products is still affected by high variability in product performance, for example due to the inherent presence of unwanted internal porosity. X-ray computed tomography (CT) has proven to be an advanced measuring technique capable of a complete analysis of pores characteristics, including distribution, size and morphology. However, previous works have shown that systematic measurement deviations occur when comparing CT with other porosity evaluation methods. In this work, the influence factors affecting CT porosity analysis were identified and investigated by experimental analyses conducted on Ti6Al4V SLM specimens and by simulated CT scans. In particular, the resolution in terms of voxel size and the surface determination method were found to have an impact on CT porosity measurement errors, that becomes more relevant for voids entrapping non-totally melted powder residues.
Enhancing CT porosity measurements on metal additive manufactured parts
FILIPPO ZANINI
;SIMONE CARMIGNATO;ENRICO SAVIO
2017
Abstract
Additive Manufacturing (AM) of metals is rapidly emerging as an innovative production technology. Nevertheless, the quality of metal AM products is still affected by high variability in product performance, for example due to the inherent presence of unwanted internal porosity. X-ray computed tomography (CT) has proven to be an advanced measuring technique capable of a complete analysis of pores characteristics, including distribution, size and morphology. However, previous works have shown that systematic measurement deviations occur when comparing CT with other porosity evaluation methods. In this work, the influence factors affecting CT porosity analysis were identified and investigated by experimental analyses conducted on Ti6Al4V SLM specimens and by simulated CT scans. In particular, the resolution in terms of voxel size and the surface determination method were found to have an impact on CT porosity measurement errors, that becomes more relevant for voids entrapping non-totally melted powder residues.Pubblicazioni consigliate
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