Electron beam powder bed fusion of Ti–1Al–8V–5Fe: Defying post-processing need with high strength and outstanding ductility
Metastable β-titanium alloys fabricated via additive manufacturing (AM) typically require substantial post-AM heat treatment to attain desirable mechanical properties. In this study, we demonstrate that Ti–1Al–8V–5Fe (Ti-185) alloy, fabricated via electron beam powder bed fusion (EB-PBF), can simult...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-09-01
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| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S223878542501854X |
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| Summary: | Metastable β-titanium alloys fabricated via additive manufacturing (AM) typically require substantial post-AM heat treatment to attain desirable mechanical properties. In this study, we demonstrate that Ti–1Al–8V–5Fe (Ti-185) alloy, fabricated via electron beam powder bed fusion (EB-PBF), can simultaneously achieve high strength and outstanding ductility without any post-process heat treatment. Microstructural and mechanical evaluations were conducted on samples from the top, middle, and bottom regions of the as-fabricated components. The as-fabricated microstructure features epitaxial columnar β grains with a distribution of grain-boundary α (αGB), microscale α (αMicro), and nanoscale α (αNano) precipitates. With increasing build height, prior-β grain width and αMicro dimensions decrease, while αNano width increases. All regions exhibit pronounced α-variant selection, especially in the top region, as quantified by pole-figure intensity and a degree-of-variant-selection (DVS) metric. Mechanical properties vary with build height, with yield strength increasing from 930 MPa at the bottom to 1075 MPa at the top, and a minimum elongation of 14 %. Notably, the bottom region exhibits an exceptional combination of 930 MPa yield strength and 28 % elongation, along with a work-hardening exponent of 0.15—exceeding the typical performance of as-fabricated Ti–6Al–4V. This places EB-PBF Ti-185 in a previously unoccupied region of the strength–ductility space. These results challenge the conventional necessity for post-processing and position EB-PBF as a viable single-step manufacturing route for producing high-performance β-titanium alloys for demanding applications such as aerospace. |
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| ISSN: | 2238-7854 |