Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion
One major advantage of additive manufacturing is the high freedom of design, which supports the fabrication of complex structures. However, geometrical features such as combined massive volumes and cellular structures in such parts can lead to an uneven heat distribution during processing, resulting...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-04-01
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| Series: | Journal of Manufacturing and Materials Processing |
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| Online Access: | https://www.mdpi.com/2504-4494/7/3/82 |
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| author | Florian Nahr Michael Rasch Christian Burkhardt Jakob Renner Benjamin Baumgärtner Tino Hausotte Carolin Körner Paul Steinmann Julia Mergheim Michael Schmidt Matthias Markl |
| author_facet | Florian Nahr Michael Rasch Christian Burkhardt Jakob Renner Benjamin Baumgärtner Tino Hausotte Carolin Körner Paul Steinmann Julia Mergheim Michael Schmidt Matthias Markl |
| author_sort | Florian Nahr |
| collection | DOAJ |
| description | One major advantage of additive manufacturing is the high freedom of design, which supports the fabrication of complex structures. However, geometrical features such as combined massive volumes and cellular structures in such parts can lead to an uneven heat distribution during processing, resulting in different material properties throughout the part. In this study, we demonstrate these effects, using a complex structure consisting of three conic shapes with narrow cylinders in between hindering heat flux. We manufacture the parts via powder bed fusion of Ti6Al4V by applying a laser beam (PBF-LB/M) as well as an electron beam (PBF-EB). We investigate the impact of the different thermal regimes on the part density, microstructure and mechanical properties aided by finite element simulations as well as by thermography and X-ray computed tomography measurements. Both simulations and thermography show an increase in inter-layer temperature with increasing part radius, subsequently leading to heat accumulation along the build direction. While the geometry and thermal history have a minor influence on the relative density of the parts, the microstructure is greatly affected by the thermal history in PBF-LB/M. The acicular martensitic structure in the narrow parts is decomposed into a mix of tempered lath-like martensite and an ultrafine <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> + <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula> microstructure with increasing part radius. The EBM part exhibits a lamellar <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> + <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula> microstructure for both the cylindric and conic structures. The different microstructures directly influence the hardness of the parts. For the PBF-LB part, the hardness ranges between 400 HV<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula> in the narrow sections and a maximum hardness of 450 HV<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula> in the broader sections, while the PBF-EB part exhibits hardness values between 280 and 380 HV<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula>. |
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| institution | Directory Open Access Journal |
| issn | 2504-4494 |
| language | English |
| last_indexed | 2024-03-11T02:17:39Z |
| publishDate | 2023-04-01 |
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| series | Journal of Manufacturing and Materials Processing |
| spelling | doaj.art-b5eaa3e0edb9492b8b9c691acc51c3242023-11-18T11:05:16ZengMDPI AGJournal of Manufacturing and Materials Processing2504-44942023-04-01738210.3390/jmmp7030082Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed FusionFlorian Nahr0Michael Rasch1Christian Burkhardt2Jakob Renner3Benjamin Baumgärtner4Tino Hausotte5Carolin Körner6Paul Steinmann7Julia Mergheim8Michael Schmidt9Matthias Markl10Institute of Photonic Technologies (LPT), Friedrich-Alexander-Universität Erlangen-Nürnberg, Konrad-Zuse-Straße 3-5, 91052 Erlangen, GermanyInstitute of Photonic Technologies (LPT), Friedrich-Alexander-Universität Erlangen-Nürnberg, Konrad-Zuse-Straße 3-5, 91052 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyInstitute of Photonic Technologies (LPT), Friedrich-Alexander-Universität Erlangen-Nürnberg, Konrad-Zuse-Straße 3-5, 91052 Erlangen, GermanyCollaborative Research Center 814–Additive Manufacturing (CRC 814), Am Weichselgarten 10, 91058 Erlangen, GermanyOne major advantage of additive manufacturing is the high freedom of design, which supports the fabrication of complex structures. However, geometrical features such as combined massive volumes and cellular structures in such parts can lead to an uneven heat distribution during processing, resulting in different material properties throughout the part. In this study, we demonstrate these effects, using a complex structure consisting of three conic shapes with narrow cylinders in between hindering heat flux. We manufacture the parts via powder bed fusion of Ti6Al4V by applying a laser beam (PBF-LB/M) as well as an electron beam (PBF-EB). We investigate the impact of the different thermal regimes on the part density, microstructure and mechanical properties aided by finite element simulations as well as by thermography and X-ray computed tomography measurements. Both simulations and thermography show an increase in inter-layer temperature with increasing part radius, subsequently leading to heat accumulation along the build direction. While the geometry and thermal history have a minor influence on the relative density of the parts, the microstructure is greatly affected by the thermal history in PBF-LB/M. The acicular martensitic structure in the narrow parts is decomposed into a mix of tempered lath-like martensite and an ultrafine <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> + <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula> microstructure with increasing part radius. The EBM part exhibits a lamellar <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> + <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula> microstructure for both the cylindric and conic structures. The different microstructures directly influence the hardness of the parts. For the PBF-LB part, the hardness ranges between 400 HV<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula> in the narrow sections and a maximum hardness of 450 HV<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula> in the broader sections, while the PBF-EB part exhibits hardness values between 280 and 380 HV<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula>.https://www.mdpi.com/2504-4494/7/3/82PBF-LB/MPBF-EBTi6Al4Vsimulationthermography |
| spellingShingle | Florian Nahr Michael Rasch Christian Burkhardt Jakob Renner Benjamin Baumgärtner Tino Hausotte Carolin Körner Paul Steinmann Julia Mergheim Michael Schmidt Matthias Markl Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion Journal of Manufacturing and Materials Processing PBF-LB/M PBF-EB Ti6Al4V simulation thermography |
| title | Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion |
| title_full | Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion |
| title_fullStr | Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion |
| title_full_unstemmed | Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion |
| title_short | Geometrical Influence on Material Properties for Ti6Al4V Parts in Powder Bed Fusion |
| title_sort | geometrical influence on material properties for ti6al4v parts in powder bed fusion |
| topic | PBF-LB/M PBF-EB Ti6Al4V simulation thermography |
| url | https://www.mdpi.com/2504-4494/7/3/82 |
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