DescriptionAdditive manufacturing (AM) can produce complex geometries unachievable using traditional subtractive methods. However, the adoption of AM technology is limited by the poor surface quality and low dimensional accuracy of AM parts. There is therefore a need to verify the quality of the completed parts, especially for safety-critical industrial sectors, e.g., aerospace, automotive and healthcare. X-ray computed tomography (XCT) is a viable method of measuring complex internal geometries and surface quality of AM parts. However, XCT measurement accuracy is affected by many influence factors, including beam hardening. The aim of the presented work was to investigate the effect of beam hardening correction (using Nikon’s 3D Pro software) on XCT dimensional measurement accuracy by comparing it against an established tactile co-ordinate measuring system(CMS). Comparisons have been made using both physical and simulated measurements. An AM cylinder with both as-built and turned surfaces has been produced to allow physical measurements using both CMS and XCT. Additionally, a virtual analogue of the sample has been synthesised to allow both CMS and XCT simulated measurements. The virtual sample was produced by mapping AM surface texture (as measured by focus variation microscopy) onto a cylindrical base geometry. The results show that XCT beam hardening corrections aid in obtaining more accurate inner dimensions but may reduce the accuracy of external dimensions. It is also shown that high order beam hardening correction alters the dimensional accuracy of both external and internal geometries.
|15 Jun 2022
|6th Dimensional X-ray Computed Tomography Conference
|Manchester, United Kingdom
|Degree of Recognition