Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content
Gamma titanium aluminides are very interesting for their use in high-performance applications such as aircraft engines due to their low density, high stiffness and favorable high-temperature properties. However, the pronounced brittleness of these intermetallic alloys is a major challenge for their...
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| Format: | Article |
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MDPI AG
2021-07-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/11/7/1093 |
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| author | Juliane Moritz Mirko Teschke Axel Marquardt Lukas Stepien Elena López Frank Brückner Marina Macias Barrientos Frank Walther Christoph Leyens |
| author_facet | Juliane Moritz Mirko Teschke Axel Marquardt Lukas Stepien Elena López Frank Brückner Marina Macias Barrientos Frank Walther Christoph Leyens |
| author_sort | Juliane Moritz |
| collection | DOAJ |
| description | Gamma titanium aluminides are very interesting for their use in high-performance applications such as aircraft engines due to their low density, high stiffness and favorable high-temperature properties. However, the pronounced brittleness of these intermetallic alloys is a major challenge for their processing through conventional fabrication methods. Additive manufacturing by means of electron beam powder bed fusion (EB-PBF) significantly improves the processability of titanium aluminides due to the high preheating temperatures and facilitates complex components. The objective of this study was to determine a suitable processing window for EB-PBF of the TNM-B1 alloy (Ti-43.5Al-4Nb-1Mo-0.1B), using an increased aluminum content in the powder raw material to compensate for evaporation losses during the process. Design of experiments was used to evaluate the effect of beam current, scan speed, focus offset, line offset and layer thickness on porosity. Top surface roughness was assessed through laser scanning confocal microscopy. Scanning electron microscopy, electron backscatter diffraction (EBSD) and energy-dispersive X-ray spectroscopy (EDX) were used for microstructural investigation and to analyze aluminum loss depending on the volumetric energy density used in EB-PBF. An optimized process parameter set for achieving part densities of 99.9% and smooth top surfaces was derived. The results regarding microstructures and aluminum evaporation suggest a solidification via the β-phase. |
| first_indexed | 2024-03-10T09:32:49Z |
| format | Article |
| id | doaj.art-d5eef1b7855741d698d29e6d5e158b72 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-10T09:32:49Z |
| publishDate | 2021-07-01 |
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| record_format | Article |
| series | Metals |
| spelling | doaj.art-d5eef1b7855741d698d29e6d5e158b722023-11-22T04:23:42ZengMDPI AGMetals2075-47012021-07-01117109310.3390/met11071093Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum ContentJuliane Moritz0Mirko Teschke1Axel Marquardt2Lukas Stepien3Elena López4Frank Brückner5Marina Macias Barrientos6Frank Walther7Christoph Leyens8Institute of Materials Science (IfWW), Technische Universität Dresden, 01069 Dresden, GermanyDepartment of Materials Test Engineering (WPT), TU Dortmund University, 44227 Dortmund, GermanyInstitute of Materials Science (IfWW), Technische Universität Dresden, 01069 Dresden, GermanyDepartment of Additive Manufacturing and Printing, Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, GermanyDepartment of Additive Manufacturing and Printing, Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, GermanyDepartment of Additive Manufacturing and Printing, Fraunhofer Institute for Material and Beam Technology IWS, 01277 Dresden, GermanyDepartment of Materials Test Engineering (WPT), TU Dortmund University, 44227 Dortmund, GermanyDepartment of Materials Test Engineering (WPT), TU Dortmund University, 44227 Dortmund, GermanyInstitute of Materials Science (IfWW), Technische Universität Dresden, 01069 Dresden, GermanyGamma titanium aluminides are very interesting for their use in high-performance applications such as aircraft engines due to their low density, high stiffness and favorable high-temperature properties. However, the pronounced brittleness of these intermetallic alloys is a major challenge for their processing through conventional fabrication methods. Additive manufacturing by means of electron beam powder bed fusion (EB-PBF) significantly improves the processability of titanium aluminides due to the high preheating temperatures and facilitates complex components. The objective of this study was to determine a suitable processing window for EB-PBF of the TNM-B1 alloy (Ti-43.5Al-4Nb-1Mo-0.1B), using an increased aluminum content in the powder raw material to compensate for evaporation losses during the process. Design of experiments was used to evaluate the effect of beam current, scan speed, focus offset, line offset and layer thickness on porosity. Top surface roughness was assessed through laser scanning confocal microscopy. Scanning electron microscopy, electron backscatter diffraction (EBSD) and energy-dispersive X-ray spectroscopy (EDX) were used for microstructural investigation and to analyze aluminum loss depending on the volumetric energy density used in EB-PBF. An optimized process parameter set for achieving part densities of 99.9% and smooth top surfaces was derived. The results regarding microstructures and aluminum evaporation suggest a solidification via the β-phase.https://www.mdpi.com/2075-4701/11/7/1093titanium aluminideadditive manufacturingelectron beam powder bed fusionelectron beam meltingprocess parameterssurface roughness |
| spellingShingle | Juliane Moritz Mirko Teschke Axel Marquardt Lukas Stepien Elena López Frank Brückner Marina Macias Barrientos Frank Walther Christoph Leyens Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content Metals titanium aluminide additive manufacturing electron beam powder bed fusion electron beam melting process parameters surface roughness |
| title | Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content |
| title_full | Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content |
| title_fullStr | Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content |
| title_full_unstemmed | Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content |
| title_short | Electron Beam Powder Bed Fusion of γ-Titanium Aluminide: Effect of Processing Parameters on Part Density, Surface Characteristics, and Aluminum Content |
| title_sort | electron beam powder bed fusion of γ titanium aluminide effect of processing parameters on part density surface characteristics and aluminum content |
| topic | titanium aluminide additive manufacturing electron beam powder bed fusion electron beam melting process parameters surface roughness |
| url | https://www.mdpi.com/2075-4701/11/7/1093 |
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