Microfocus X-Ray Computed Tomography (CT) Analysis Of Laser Sintered Parts

Abstract

Microfocus X-ray computed tomography (CT) scanning is a three-dimensional (3D) nondestructive technique that is useful in many research and technology fields. Similar to twodimensional (2D) X-ray inspections, this 3D technology allows the investigation of almost any material down to 1 micron spatial resolution and higher. In this paper we present a characterisation and demonstration of the use of CT to analyse the 3D volume of laser sintered parts including analyses of porosity, dimensional measurement of cracks and other features, and a demonstration of quality testing methods which can be used to quickly identify problems in production. OPSOMMINGMikrofokus X-straal rekenaar-tomografie (RT) is 'n drie-dimensionele (3D) nie-destruktiewe tegniek wat bruikbaar is in baie navorsing en tegnologie velde. Soortgelyk aan twee dimensionele (2D) X-straal inspeksies, laat hierdie 3D tegnologie dit toe om enige materiaal in 3D te ondersoek tot 1 mikron (en hoër) ruimtelike resolusie. In hierdie artikel word 'n karakterisering en demonstrasie van die gebruik van RT aangebied om die 3D volume van laser-gesinterde onderdele te analiseer, insluitend die analise van porositeit, dimensionele metings van krake en ander eienskappe en 'n demonstrasie van kwaliteit toets metodes wat gebruik kan word om vinnig probleme in produksie te identifiseer.

Directionality of Cavities and Porosity Formation in Powder-Bed Laser Additive Manufacturing of Metal Components Investigated Using X-Ray Tomography

“…13 Some porosity analysis by CT analysis of additive manufactured metals is reported in the study by Becker et al 14 The authors of this present article have reported the methodology for nondestructive testing and qualification of additively manufactured medical implants at various resolutions and scan parameters (du Plessis et al, unpublished material). The general use of X-ray tomography in additive manufactured part inspection has also been reported in the study by du Plessis et al 15 and recently has been shown to also be useful for dimensional accuracy assessment for consumer-grade 3D printing, where the same methodology can be applied to any additive process. 16 Recently, a very flat layered form of defect was reported using X-ray tomography of an additive manufactured test part, which is speculated to be due to improper fusion in one or more layers of powder.…”

Tensile Properties and Microstructure of Direct Metal Laser-Sintered Ti6al4v (Eli) Alloy

“…The samples were subjected to X-ray micro-computed tomography (MicroCT) [14]. MicroCT scans were done with a General Electric Phoenix V|Tome|X L240 system at 160 kV and 200 μA, including beam filtering of 0.5 mm copper; the resolution was 10 μm.…”

X-ray Micro-Ct Supporting the South African Additive Manufacturing Community ^†

“…This requires very high scan quality and advanced software tools to allow sub-voxel precision, something which is not always available and was not available at the Stellenbosch CT facility until 2014. Prior to this, various analyses were possible, but precision was limited to basic edge determination tools as shown in a Rapdasa proceedings paper in [17]. The advanced surface determination is demonstrated on a 10 mm Ti6Al4V cube in Figure 4, showing the 3D interpolation of grey values to determine the exact surface location -with high scan quality this can be as accurate as 1/10 th the voxel size.…”