Build orientation effects on the roughness of SLM channels

C. G. Klingaa*, T. Dahmen, S. Baier, S. Mohanty, J. H. Hattel

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsResearchpeer-review

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Abstract

Increasingly advanced shapes and geometries are being manufactured using additive manufacturing and new characterization techniques must emerge in order to fully utilize the new possibilities given by freeform design. Cooling channels produced by the laser powder bed fusion process has been shown to have high roughness at overhanging areas due to powder particles being fused with the internal surface. Classic techniques for characterizing profile roughness are falling short with respect to internal surfaces in freeform geometries. Hence, this work presents a methodology for characterizing internal surface roughness by extracting roughness profiles through the use of image analysis and X-ray CT. In order to fully describe the internal surface roughness, two orientations were defined, namely the global and local orientations α and β. The internal profile roughness was evaluated in accordance with ISO 4287:1997. Seven selective laser melting manufactured straight channels made in 17-4 PH stainless steel were CT scanned and analyzed with the proposed methodology. Results showed that the Ra-values inside the channel were dependent on both α and β. The average Ra-values and their standard deviations were found to be decreasing rapidly with increasing α. The highest average roughness was found for α = 0°, where an average Ra-value of 70.7 μm was found. The lowest average roughness was found at α = 90°, where an average Ra-value of 6.7 μm was found. Furthermore, it was found that the surface texture and roughness changed dependent on the location along the length of the channel produced at α = 0°. These findings suggest the importance of characterizing the internal surface roughness of cooling channels with respect to both the global build orientation of a channel, the local orientation within a channel and the specific location along the length of a channel.
Original languageEnglish
Title of host publicationProceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019)
EditorsA. Bernard, R.K. Leach, D.B. Pedersen, J.S. Taylor
PublisherThe European Society for Precision Engineering and Nanotechnology
Publication date2019
Pages111-114
ISBN (Electronic)978-0-9957751-5-2
Publication statusPublished - 2019
EventJoint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing - Ecole Centrale de Nantes, Nantes, France
Duration: 16 Sep 201918 Sep 2019

Conference

ConferenceJoint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing
LocationEcole Centrale de Nantes
CountryFrance
CityNantes
Period16/09/201918/09/2019

Keywords

  • SLM
  • Powder bed fusion
  • Additive manufacturing
  • Sooling channels
  • X-ray CT
  • Roughness analysis

Cite this

Klingaa, C. G., Dahmen, T., Baier, S., Mohanty, S., & Hattel, J. H. (2019). Build orientation effects on the roughness of SLM channels. In A. Bernard, R. K. Leach, D. B. Pedersen, & J. S. Taylor (Eds.), Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019) (pp. 111-114). The European Society for Precision Engineering and Nanotechnology.
Klingaa, C. G. ; Dahmen, T. ; Baier, S. ; Mohanty, S. ; Hattel, J. H. / Build orientation effects on the roughness of SLM channels. Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019). editor / A. Bernard ; R.K. Leach ; D.B. Pedersen ; J.S. Taylor. The European Society for Precision Engineering and Nanotechnology, 2019. pp. 111-114
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abstract = "Increasingly advanced shapes and geometries are being manufactured using additive manufacturing and new characterization techniques must emerge in order to fully utilize the new possibilities given by freeform design. Cooling channels produced by the laser powder bed fusion process has been shown to have high roughness at overhanging areas due to powder particles being fused with the internal surface. Classic techniques for characterizing profile roughness are falling short with respect to internal surfaces in freeform geometries. Hence, this work presents a methodology for characterizing internal surface roughness by extracting roughness profiles through the use of image analysis and X-ray CT. In order to fully describe the internal surface roughness, two orientations were defined, namely the global and local orientations α and β. The internal profile roughness was evaluated in accordance with ISO 4287:1997. Seven selective laser melting manufactured straight channels made in 17-4 PH stainless steel were CT scanned and analyzed with the proposed methodology. Results showed that the Ra-values inside the channel were dependent on both α and β. The average Ra-values and their standard deviations were found to be decreasing rapidly with increasing α. The highest average roughness was found for α = 0°, where an average Ra-value of 70.7 μm was found. The lowest average roughness was found at α = 90°, where an average Ra-value of 6.7 μm was found. Furthermore, it was found that the surface texture and roughness changed dependent on the location along the length of the channel produced at α = 0°. These findings suggest the importance of characterizing the internal surface roughness of cooling channels with respect to both the global build orientation of a channel, the local orientation within a channel and the specific location along the length of a channel.",
keywords = "SLM, Powder bed fusion, Additive manufacturing, Sooling channels, X-ray CT, Roughness analysis",
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Klingaa, CG, Dahmen, T, Baier, S, Mohanty, S & Hattel, JH 2019, Build orientation effects on the roughness of SLM channels. in A Bernard, RK Leach, DB Pedersen & JS Taylor (eds), Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019). The European Society for Precision Engineering and Nanotechnology, pp. 111-114, Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing, Nantes, France, 16/09/2019.

Build orientation effects on the roughness of SLM channels. / Klingaa, C. G.; Dahmen, T.; Baier, S.; Mohanty, S.; Hattel, J. H.

Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019). ed. / A. Bernard; R.K. Leach; D.B. Pedersen; J.S. Taylor. The European Society for Precision Engineering and Nanotechnology, 2019. p. 111-114.

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsResearchpeer-review

TY - ABST

T1 - Build orientation effects on the roughness of SLM channels

AU - Klingaa, C. G.

AU - Dahmen, T.

AU - Baier, S.

AU - Mohanty, S.

AU - Hattel, J. H.

PY - 2019

Y1 - 2019

N2 - Increasingly advanced shapes and geometries are being manufactured using additive manufacturing and new characterization techniques must emerge in order to fully utilize the new possibilities given by freeform design. Cooling channels produced by the laser powder bed fusion process has been shown to have high roughness at overhanging areas due to powder particles being fused with the internal surface. Classic techniques for characterizing profile roughness are falling short with respect to internal surfaces in freeform geometries. Hence, this work presents a methodology for characterizing internal surface roughness by extracting roughness profiles through the use of image analysis and X-ray CT. In order to fully describe the internal surface roughness, two orientations were defined, namely the global and local orientations α and β. The internal profile roughness was evaluated in accordance with ISO 4287:1997. Seven selective laser melting manufactured straight channels made in 17-4 PH stainless steel were CT scanned and analyzed with the proposed methodology. Results showed that the Ra-values inside the channel were dependent on both α and β. The average Ra-values and their standard deviations were found to be decreasing rapidly with increasing α. The highest average roughness was found for α = 0°, where an average Ra-value of 70.7 μm was found. The lowest average roughness was found at α = 90°, where an average Ra-value of 6.7 μm was found. Furthermore, it was found that the surface texture and roughness changed dependent on the location along the length of the channel produced at α = 0°. These findings suggest the importance of characterizing the internal surface roughness of cooling channels with respect to both the global build orientation of a channel, the local orientation within a channel and the specific location along the length of a channel.

AB - Increasingly advanced shapes and geometries are being manufactured using additive manufacturing and new characterization techniques must emerge in order to fully utilize the new possibilities given by freeform design. Cooling channels produced by the laser powder bed fusion process has been shown to have high roughness at overhanging areas due to powder particles being fused with the internal surface. Classic techniques for characterizing profile roughness are falling short with respect to internal surfaces in freeform geometries. Hence, this work presents a methodology for characterizing internal surface roughness by extracting roughness profiles through the use of image analysis and X-ray CT. In order to fully describe the internal surface roughness, two orientations were defined, namely the global and local orientations α and β. The internal profile roughness was evaluated in accordance with ISO 4287:1997. Seven selective laser melting manufactured straight channels made in 17-4 PH stainless steel were CT scanned and analyzed with the proposed methodology. Results showed that the Ra-values inside the channel were dependent on both α and β. The average Ra-values and their standard deviations were found to be decreasing rapidly with increasing α. The highest average roughness was found for α = 0°, where an average Ra-value of 70.7 μm was found. The lowest average roughness was found at α = 90°, where an average Ra-value of 6.7 μm was found. Furthermore, it was found that the surface texture and roughness changed dependent on the location along the length of the channel produced at α = 0°. These findings suggest the importance of characterizing the internal surface roughness of cooling channels with respect to both the global build orientation of a channel, the local orientation within a channel and the specific location along the length of a channel.

KW - SLM

KW - Powder bed fusion

KW - Additive manufacturing

KW - Sooling channels

KW - X-ray CT

KW - Roughness analysis

M3 - Conference abstract in proceedings

SP - 111

EP - 114

BT - Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019)

A2 - Bernard, A.

A2 - Leach, R.K.

A2 - Pedersen, D.B.

A2 - Taylor, J.S.

PB - The European Society for Precision Engineering and Nanotechnology

ER -

Klingaa CG, Dahmen T, Baier S, Mohanty S, Hattel JH. Build orientation effects on the roughness of SLM channels. In Bernard A, Leach RK, Pedersen DB, Taylor JS, editors, Proceedings of the Joint Special Interest Group meeting between euspen and ASPE Advancing Precision in Additive Manufacturing (2019). The European Society for Precision Engineering and Nanotechnology. 2019. p. 111-114