On the hot deformation behavior of Ti-6Al-4V made by additive manufacturing
Bambach M, Sizova I, Szyndler J, Bennett J, Hyatt G, Cao J, Papke T, Merklein M (2021)
Publication Type: Journal article
Publication year: 2021
Journal
Book Volume: 288
Article Number: 116840
DOI: 10.1016/j.jmatprotec.2020.116840
Abstract
Innovative process chains that use additive manufacturing (AM) to produce pre-forms for hot forging have been proposed recently, but almost no scientific knowledge on the hot deformation behavior of AM material exists. The combination of AM and metal forming may allow for producing pre-forms by AM which can be forged to the final shape in a single forming operation, thus saving tooling costs compared to conventional multi-stage forging processes. In this work, Ti-6Al-4 V samples made from powder using Directed Energy Deposition (DED) and Selective Laser Melting (SLM) are investigated under typical hot working conditions. An increasing cooling rate in AM promotes the formation of martensite. When heated to forming temperature, the martensite decomposes and yields intermediate microstructures with improved hot working properties compared to conventional wrought material. Differences in the flow stress and activation energy for hot working are analyzed for conventional and as-built Ti-6Al-4 V. AM material exhibits both lower flow stresses and a faster globularization rate, which is explained by non-equilibrium phase fractions and the spatial arrangement of the β-phase. A model is proposed to predict flow stresses and microstructure evolution in Ti-6Al-4 V specimens with a conventional and AM microstructure, which takes the spatial arrangement into account. The findings can be used to design new process chains that allow for single-stage net-shape forging of Ti-6Al-4 V parts at reduced forming forces and with improved mechanical properties.
Authors with CRIS profile
Thomas Papke
Institute of Manufacturing Technology
Marion Merklein
Institute of Manufacturing Technology
Involved external institutions
Northwestern University
United States (USA) (US)
Brandenburgische Technische Universität Cottbus-Senftenberg (BTU)
Germany (DE)
United States (USA) (US)
Brandenburgische Technische Universität Cottbus-Senftenberg (BTU)
Germany (DE)
How to cite
APA:
Bambach, M., Sizova, I., Szyndler, J., Bennett, J., Hyatt, G., Cao, J.,... Merklein, M. (2021). On the hot deformation behavior of Ti-6Al-4V made by additive manufacturing. Journal of Materials Processing Technology, 288. https://dx.doi.org/10.1016/j.jmatprotec.2020.116840
MLA:
Bambach, Markus, et al. "On the hot deformation behavior of Ti-6Al-4V made by additive manufacturing." Journal of Materials Processing Technology 288 (2021).
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