Characterization of an Additive Manufactured TiAl Alloy—Steel Joint Produced by Electron Beam Welding
AbstractIn this work, the characterization of the assembly of a steel shaft into a γ-TiAl part for turbocharger application, obtained using Electron Beam Welding (EBW) technology with a Ni-based filler, was carried out. The Ti-48Al-2Nb-0.7Cr-0.3Si (at %) alloy part was produced by Electron Beam Melting (EBM). This additive manufacturing technology allows the production of a lightweight part with complex shapes. The replacement of Nickel-based superalloys with TiAl alloys in turbocharger automotive applications will lead to an improvement of the engine performance and a substantial reduction in fuel consumption and emission. The welding process allows a promising joint to be obtained, not affecting the TiAl microstructure. Nevertheless, it causes the formation of diffusive layers between the Ni-based filler and both steel and TiAl, with the latter side being characterized by a very complex microstructure, which was fully characterized in this paper by means of Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, and nanoindentation. The diffusive interface has a thickness of about 6 µm, and it is composed of several layers. Specifically, from the TiAl alloy side, we find a layer of Ti3Al followed by Al3NiTi2 and AlNi2Ti. Subsequently Ni becomes more predominant, with a first layer characterized by abundant carbide/boride precipitation, and a second layer characterized by Si-enrichment. Then, the chemical composition of the Ni-based filler is gradually reached. View Full-Text
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Basile, G.; Baudana, G.; Marchese, G.; Lorusso, M.; Lombardi, M.; Ugues, D.; Fino, P.; Biamino, S. Characterization of an Additive Manufactured TiAl Alloy—Steel Joint Produced by Electron Beam Welding. Materials 2018, 11, 149.
Basile G, Baudana G, Marchese G, Lorusso M, Lombardi M, Ugues D, Fino P, Biamino S. Characterization of an Additive Manufactured TiAl Alloy—Steel Joint Produced by Electron Beam Welding. Materials. 2018; 11(1):149.Chicago/Turabian Style
Basile, Gloria; Baudana, Giorgio; Marchese, Giulio; Lorusso, Massimo; Lombardi, Mariangela; Ugues, Daniele; Fino, Paolo; Biamino, Sara. 2018. "Characterization of an Additive Manufactured TiAl Alloy—Steel Joint Produced by Electron Beam Welding." Materials 11, no. 1: 149.
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