Microstructure and oxide particle stability in a novel ODS γ-TiAl alloy processed by spark plasma sintering and laser additive manufacturing



Kenel, C, Dawson, K ORCID: 0000-0003-3249-8328, Barras, J, Hauser, C, Dasargyri, G, Bauer, T, Colella, A, Spierings, AB, Tatlock, GJ, Leinenbach, C
et al (show 1 more authors) (2017) Microstructure and oxide particle stability in a novel ODS γ-TiAl alloy processed by spark plasma sintering and laser additive manufacturing. Intermetallics, 90. 63 - 73.

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Abstract

In this work, a novel oxide dispersion strengthened titanium aluminide alloy (Ti-45Al-3Nb-<0.2Y2O3 at.%) was developed for powder-based processing technologies with a focus on spark plasma sintering and additive manufacturing. Titanium aluminides are promising structural intermetallics for weight reduction and an increased performance of high temperature components. The alloy design and selection process was supported by computational thermodynamics based on the CALPHAD approach, taking into account requirements for processing as well as long term alloy behavior under service conditions. Processing trials using spark plasma sintering, direct metal deposition and selective laser melting were conducted to study the alloy behavior, microstructure formation and introduction as well as stability of the ODS particles. Additionally, thermal annealing on the sintered and laser consolidated material was performed. Conventional dual phase α2-Ti3Al and γ-TiAl duplex and near-lamellar microstructures were obtained from the processed material. The ODS particles were homogeneously distributed in the alloy matrix after processing in the liquid state. For the direct metal deposition process, the novel alloy was compared to the established GE48-2-2 alloy (Ti-48Al-2Cr-2Nb) in terms of phases, microstructure and texture after processing. A significantly reduced texture formation was observed with the novel alloy. The hardness of the consolidated material shows superior properties for ODS-containing TiAl compared to ODS-free material. This work provides a first step towards tailored alloys for AM and the production of ODS TiAl alloys.

Item Type: Article
Additional Information: publisher: Elsevier articletitle: Microstructure and oxide particle stability in a novel ODS γ-TiAl alloy processed by spark plasma sintering and laser additive manufacturing journaltitle: Intermetallics articlelink: http://dx.doi.org/10.1016/j.intermet.2017.07.004 content_type: article copyright: © 2017 The Authors. Published by Elsevier Ltd.
Uncontrolled Keywords: Gamma-TiAl, Oxide dispersion strengthened, Additive manufacturing, Spark plasma sintering
Depositing User: Symplectic Admin
Date Deposited: 28 Jul 2017 15:13
Last Modified: 21 Apr 2021 20:16
DOI: 10.1016/j.intermet.2017.07.004
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3008691