Details
| Original language | English |
|---|---|
| Article number | 100837 |
| Journal | Additive Manufacturing |
| Volume | 30 |
| Early online date | 13 Sept 2019 |
| Publication status | Published - Dec 2019 |
| Externally published | Yes |
Abstract
This paper reports on the results of a round robin test conducted by ten X-ray micro computed tomography (micro-CT) laboratories with the same three selected titanium alloy (Ti6Al4V) laser powder bed fusion (L-PBF) test parts. These parts were a 10-mm cube, a 60-mm long and 40-mm high complex-shaped bracket, and a 15-mm diameter rod. Previously developed protocols for micro-CT analysis of these parts were provided to all participants, including suggested scanning parameters and image analysis steps. No further information on the samples were provided, and they were selected from a variety of parts from a previous different type of round robin study where various L-PBF laboratories provided identical parts for micro-CT analysis at one laboratory. In this new micro-CT round robin test which involves various micro-CT laboratories, parts from the previous work were selected such that each part had a different characteristic flaw type, and all laboratories involved in the study analyzed the same set of parts. The 10-mm cube contained subsurface pores just under its top surface (relative to build direction), and all participants could positively identify this. The complex bracket had contour pores around its outer vertical sides, and was warped with two arms deflected towards one another. Both of these features were positively identified by all participants. The 15-mm diameter rod had a layered stop/start flaw, which was also positively identified by all participants. Differences were found among participants for quantitative evaluations, ranging from no quantitative measurement made, to under and overestimation of the values in all analyses attempted. This round robin provides the opportunity to highlight typical causes of errors in micro-CT scanning and image analysis as applied to additively manufactured parts. Some workflow variations, sources of error and ways to increase the reproducibility of such analysis workflows are discussed. The ultimate aim of this work is to advance the efficient use of micro-CT facilities for process optimization and quality inspections for additively manufactured products. The results provide confidence in the use of laboratory micro-CT but also indicate the need for further development of standards, protocols and image analysis workflows for quantitative assessment, especially for direct and quantitative comparisons between different laboratories.
Keywords
- Additive manufacturing, Flaw detection, Laser powder bed fusion, Non-destructive testing, Seeded flaws, X-ray tomography, microCT
ASJC Scopus subject areas
- Engineering(all)
- Biomedical Engineering
- Materials Science(all)
- General Materials Science
- Engineering(all)
- Engineering (miscellaneous)
- Engineering(all)
- Industrial and Manufacturing Engineering
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In: Additive Manufacturing, Vol. 30, 100837, 12.2019.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Laboratory X-ray tomography for metal additive manufacturing: Round robin test
AU - du Plessis, Anton
AU - du Roux, Stephan G.
AU - Waller, Jess
AU - Sperling, Philip
AU - Achilles, Nils
AU - Beerlink, Andre
AU - Métayer, Francois
AU - Sinico, Mirko
AU - Probst, Gabriel
AU - Dewulf, Wim
AU - Bittner, Florian
AU - Endres, Hans-Josef
AU - Willner, Marian
AU - Drégelyi-Kiss, Agota
AU - Zikmund, Tomas
AU - Laznovsky, Jakub
AU - Kaiser, Jozef
AU - Pinter, Pascal
AU - Dietrich, Stefan
AU - Lopez, Elena
AU - Fitzek, Oliver
AU - Konrad, Porebski
N1 - Funding Information: The South African Department of Science and Technology is acknowledged for support through the Collaborative Program for Additive Manufacturing (CPAM). This research was carried out under the project CEITEC 2020 (LQ1601) with financial support from the Ministry of Education, Youth and Sports of the Czech Republic under the National Sustainability Programme II and support of CEITEC Nano Research Infrastructure (MEYS CR, 2016?2019). Mirko Sinico kindly acknowledges the funding from the H2020-MSCA-ITN-2016 project PAM2 (Precision Additive Metal Manufacturing), EU Framework Programme for Research and Innovation H2020 Grant Agreement No721383.
PY - 2019/12
Y1 - 2019/12
N2 - This paper reports on the results of a round robin test conducted by ten X-ray micro computed tomography (micro-CT) laboratories with the same three selected titanium alloy (Ti6Al4V) laser powder bed fusion (L-PBF) test parts. These parts were a 10-mm cube, a 60-mm long and 40-mm high complex-shaped bracket, and a 15-mm diameter rod. Previously developed protocols for micro-CT analysis of these parts were provided to all participants, including suggested scanning parameters and image analysis steps. No further information on the samples were provided, and they were selected from a variety of parts from a previous different type of round robin study where various L-PBF laboratories provided identical parts for micro-CT analysis at one laboratory. In this new micro-CT round robin test which involves various micro-CT laboratories, parts from the previous work were selected such that each part had a different characteristic flaw type, and all laboratories involved in the study analyzed the same set of parts. The 10-mm cube contained subsurface pores just under its top surface (relative to build direction), and all participants could positively identify this. The complex bracket had contour pores around its outer vertical sides, and was warped with two arms deflected towards one another. Both of these features were positively identified by all participants. The 15-mm diameter rod had a layered stop/start flaw, which was also positively identified by all participants. Differences were found among participants for quantitative evaluations, ranging from no quantitative measurement made, to under and overestimation of the values in all analyses attempted. This round robin provides the opportunity to highlight typical causes of errors in micro-CT scanning and image analysis as applied to additively manufactured parts. Some workflow variations, sources of error and ways to increase the reproducibility of such analysis workflows are discussed. The ultimate aim of this work is to advance the efficient use of micro-CT facilities for process optimization and quality inspections for additively manufactured products. The results provide confidence in the use of laboratory micro-CT but also indicate the need for further development of standards, protocols and image analysis workflows for quantitative assessment, especially for direct and quantitative comparisons between different laboratories.
AB - This paper reports on the results of a round robin test conducted by ten X-ray micro computed tomography (micro-CT) laboratories with the same three selected titanium alloy (Ti6Al4V) laser powder bed fusion (L-PBF) test parts. These parts were a 10-mm cube, a 60-mm long and 40-mm high complex-shaped bracket, and a 15-mm diameter rod. Previously developed protocols for micro-CT analysis of these parts were provided to all participants, including suggested scanning parameters and image analysis steps. No further information on the samples were provided, and they were selected from a variety of parts from a previous different type of round robin study where various L-PBF laboratories provided identical parts for micro-CT analysis at one laboratory. In this new micro-CT round robin test which involves various micro-CT laboratories, parts from the previous work were selected such that each part had a different characteristic flaw type, and all laboratories involved in the study analyzed the same set of parts. The 10-mm cube contained subsurface pores just under its top surface (relative to build direction), and all participants could positively identify this. The complex bracket had contour pores around its outer vertical sides, and was warped with two arms deflected towards one another. Both of these features were positively identified by all participants. The 15-mm diameter rod had a layered stop/start flaw, which was also positively identified by all participants. Differences were found among participants for quantitative evaluations, ranging from no quantitative measurement made, to under and overestimation of the values in all analyses attempted. This round robin provides the opportunity to highlight typical causes of errors in micro-CT scanning and image analysis as applied to additively manufactured parts. Some workflow variations, sources of error and ways to increase the reproducibility of such analysis workflows are discussed. The ultimate aim of this work is to advance the efficient use of micro-CT facilities for process optimization and quality inspections for additively manufactured products. The results provide confidence in the use of laboratory micro-CT but also indicate the need for further development of standards, protocols and image analysis workflows for quantitative assessment, especially for direct and quantitative comparisons between different laboratories.
KW - Additive manufacturing
KW - Flaw detection
KW - Laser powder bed fusion
KW - Non-destructive testing
KW - Seeded flaws
KW - X-ray tomography
KW - microCT
UR - http://www.scopus.com/inward/record.url?scp=85072575914&partnerID=8YFLogxK
U2 - 10.1016/j.addma.2019.100837
DO - 10.1016/j.addma.2019.100837
M3 - Article
VL - 30
JO - Additive Manufacturing
JF - Additive Manufacturing
M1 - 100837
ER -