A comparative study of Ti-Al and Ti-Nb alloys for advanced technological applications

• Autorzy: Peter I. , Rosso M. , Castella C.
• Języki publikacji: EN

Abstrakty

EN

Purpose: of this paper is to compare some properties of Ti-Al and Ti-Nb alloys to investigate on the possibility to jointly employed them industrially. Ti-Al alloys have been proposed because they present challenging characteristics for high temperature purposes and β type Ti-Nb alloy has specific mechanical properties at room temperature. Ti-Al alloys are very attractive materials and represent one of the most important materials employed for aero jet engines. The most promising alloy belonging to the above mentioned classes are predominantly based on simultaneously presence of two phases, namely γ-TiAl (gamma titanium aluminides) and α2-Ti3Al both with a fully lamellar microstructure and could replace Ni-based superalloys in some high temperature applications in aerospace and automotive industries. The most important advantages of such alloys compared to some superalloys consist in their low density correlated to their superior efficiency in service and reduced gas emission. Design/methodology/approach: The Ti-Al alloy have been produced by gravity casting, using a vibrating furnace, while the Ti-Nb alloy samples have been realized by the cold crucible levitation melting (CCLM) casting technology. Microstructural and mechanical characterization have been performed. Findings: The microstructural analysis for the Ti-Al alloy reveals a fully-lamellar microstructure with alternate plates of α2-(Ti3Al) and γ-(TiAl) plates. The grains have an average size of about 200 μm. For the Ti-Nb based alloy only a β mono-phase has been detected. This alloy has a equiaxed microstructure with an average grain dimension of about 170 μm. The Ti-Nb alloy presents a high mechanical strength while on the contrary that of the Ti-Al has been deleteriously affected by the presence of large gas porosities. Superior hardness values have been reached with Ti-Al alloy, due to the presence of hard γ-TiAl. Practical implications: The most important implication is related to the transfer toward the proper choice of the correct parameters during manufacturing. Originality/value: Investigation on the influence of the elemental composition enriched by other elements and casting processes on the defect development, the microstructural characteristics and on the mechanical behaviour of the alloys.

Słowa kluczowe

EN

metallic alloys; intermetallic phase; microstructural characterization

PL

stopy metalowe; faza międzymetaliczna; charakterystyka mikrostruktury

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2015
• Tom: Vol. 73, nr 2
• Strony: 199--205
• Opis fizyczny: Bibliogr. 22 poz., rys., tab., wykr.

Twórcy

autor

Peter I.

• Politecnico di Torino, Department of Applied Science and Technology Corso Duca degli Abruzzi 24, Torino, Italy

autor

Rosso M.

• Politecnico di Torino, Department of Applied Science and Technology Corso Duca degli Abruzzi 24, Torino, Italy

autor

Castella C.

• Politecnico di Torino, Department of Applied Science and Technology Corso Duca degli Abruzzi 24, Torino, Italy

Bibliografia

• [1] M. Kastenhuber, B. Rashkova, H. Clemens, S. Mayer, Enhancement of creep properties and microstructural stability of intermetallic β-solidifying γ-TiAl based alloys, Intermetallics 63 (2015) 19-26.
• [2] R. Pflumm, S. Friedle, M. Schütze, Oxidation protection of γ-TiAl-based alloys - A review, Intermetallics 56 (2015) 1-14.
• [3] J. Cheng, F. Li, Z. Qiao, S. Zhu, J. Yang, W. Liu, The role of oxidation and counterface in the high temperature tribological properties of TiAl intermetallics, Materials and Design 84 (2015) 245-253.
• [4] T. Klein, M. Schachermayer, F. Mendez-Martin, T. Schoberl, B. Rashkova, H. Clemensa, S. Mayer, Carbon distribution in multi-phase γ-TiAl based alloys and its influence on mechanical properties and phase formation, Acta Materialia 94 (2015) 205-213.
• [5] S.Y. Sung, Y.J. Kim, Modeling of titanium aluminides turbo-charger casting, Intermetallics 15 (2007) 468-474.
• [6] L. Yang, L.H. Chai, Y.L. Wang, S.B. Gao, L. Song, J.P. Lin, Precipitates in high-Nb TiAl alloyed with Si, Materials Letters 154 (2015) 8-11.
• [7] G.E. Bean, M.S. Kesler, M.V. Manuel, Effect of Nb on phase transformations and microstructure in high Nb titanium aluminides, Journal of Alloys and Compounds 613 (2014) 351-356.
• [8] L. Settineri, P.C. Priarone, M. Arft, D. Lung, T. Stoyanov, An evaluative approach to correlate machinability, microstructures, and material properties of gamma titanium aluminides, CIRP Annals - Manufacturing Technology 63 (2014) 57-60.
• [9] D.K. Aspinwall, R.C. Dewes, A.L. Mantle The Machining of g-TiAl Intermetallic Alloys. CIRP Annals-Manufacturing Technology (2005) 54/1:99-104.
• [10] S. Kuramoto, T. Furuta, J. Hwang, K. Nishino, T. Saito, Elastic properties of Gum Metal, Materials Science and Engineering A 442 (2006) 454-457.
• [11] M. Tane, T. Nakano, S. Kuramoto, M. Niinomi, N. Takesue, H. Nakajima, ωTransformation in cold-worked Ti-Nb-Ta-Zr-O alloys with low body-centered cubic phase stability and its correlation with their elastic properties, Acta Materialia 61 (2013) 139-150.
• [12] T. Furuta, S. Kuramoto, J.W. Morris, N. Nagasako, E. Withey, D.C. Chrzan, The mechanism of strength and deformation in Gum Metal, Scripta Materialia 68 (2013) 767-772.
• [13] T. Saito, T. Furuta, J.H. Hwang, S. Kuramoto, K. Nishino, N. Suzuki, R. Chen, A. Yamada, K. Ito, Y. Seno, T. Nonaka, H. Ikehata, N. Nagasako, C. Iwamoto, Y. Ikuhara, T. Sakuma, Multifunctional Alloys Obtained via a Dislocation-Free Plastic Deformation Mechanism, Science 300 (2003) 464-467.
• [14] R.J. Talling, R.J. Dashwood, M. Jackson, S. Kuramotoc, D. Dye, Determination of (C11 C12) in Ti-36Nb-2Ta-3Zr-0.3O (wt.%) (Gum meta), Scripta Materialia 59 (2008) 669-672.
• [15] R.J. Talling, R.J. Dashwood, M. Jackson, D. Dye, On the mechanism of superelasticity in Gum metal, Acta Materialia 57 (2009) 1188-1198.
• [16] V.A. Vorontsov, N.G. Jones, K.M. Raham, D. Dye, Superelastic load cycling of Gum Metal, Acta Materialia 88 (2015) 323-333.
• [17] C.Yuan, X. Cheng, G.S. Holt, D. Shevchenko, P.A. Withey, Investment casting of Ti-46Al-8Nb-1Balloy using moulds with CaO-stabilized zirconia face coat at various mould pre-heat temperatures, Ceramics International 41 (2015) 4129-4139.
• [18] R.A. Harding, M. Wickins, H. Wang, G. Djambazov, K.A. Pericleous, Development of a turbulence-free casting technique for titanium aluminides, Intermetallics 19 (2011) 805-813.
• [19] K. Kothari, R. Radhakrishnan, N.M. Wereley, Advances in gamma titanium aluminides and their manufacturing techniques, Progress in Aerospace Sciences 55 (2012) 1-16.
• [20] H.Z. Niu, Y.Y. Chen, Y.S. Zhang, J.W. Lu, W. Zhang, P.X. Zhang, Producing fully-lamellar microstructure for wrought beta-gamma TiAl alloys without single α-phase field, Intermetallics 59 (2015) 87-94.
• [21] S. Djanarthany, J.C. Viala, J. Bouix, An overview of monolithic titanium aluminides based on Ti3Al and TiAl, Materials Chemistry and Physics 72 (2001) 301-319.
• [22] T. Furuta, S. Kuramoto, J. Hwang, K. Nishino, T. Saito, Elastic Deformation Behavior of Multi-Functional Ti-Nb-Ta-Zr-O Alloys, Materials Transactions 46/12 (2005) 3001-3007.