Investigation of Structural Properties and Martensitic Phase Transformations in Heat-treated Ni-25.5 at. %Ta High Temperature Shape Memory Alloys

Year 2020, , 391 - 402, 25.06.2020

Köksal Yıldız

https://doi.org/10.37094/adyujsci.733778

Cited By: 2

Abstract

The effect of heat treatment performed at 800 °C, 900 °C and 1000 °C for 1 hour on structural and martensitic transformation properties of Ni-25.5 at.%Ta high temperature shape memory alloy has been examined. Morphological observations by SEM-EDS showed that the heat treatment affected directly microstructural properties of the alloy. Microstructure of the heat treated samples is composed of intermetallic Ni-rich Ni8Ta and Ta-rich NiTa2 compound in the Ni3Ta matrix. In addition to these phases, orthorhombic Ni3Ta phase was only observed in the sample heat-treated at 1000 °C. Structural investigations of alloy the samples by XRD indicated that the martensitic crystal orientation of the samples changed with heat treatments. DSC measurements revealed that all the samples displayed high temperature shape memory behavior with martensitic transformation temperatures of above 200 °C. Vicker’s microhardness measurements showed that the microhardness of the alloy influenced dramatically by applying heat treatments, especially at 800 and 900°C.

Keywords

Ni3Ta, martensite, heat treatment

Supporting Institution

Scientific Research Projects Coordination Unit of Firat University

Project Number

FF.16.36

Thanks

The author also thanks to Professor Soner ÖZGEN for his technical support under Project number: FF.15.17

References

• [1] Jani, J.M., Leary, M., Subic, A., Gibson, M.A., A review of shape memory alloy research, applications and opportunities, Materials and Design, 56, 1078-1113, 2014.
• [2] Taşkan, E., Bulak, S., Taşkan, B., Şaşmaz, M., El Abed, S., El Abed, A., Nitinol as a suitable anode material for electricity generation in microbial fuel cells, Bioelectrochemistry, 128, 118-125, 2019.
• [3] Rudajevová, A., Pospíšil, J., Shape memory behavior of a Ni3Ta alloy pre-deformed in compression, Materials Science and Engineering A, 527, 2900-2905, 2010.
• [4] Wu, K., Ma, J.L., A review of high-temperature shape memory alloys, Proceedings of the SMST, p.153, 2000.
• [5] Ma, J., Karaman, I., Noebe, R.D., High temperature shape memory alloys, International Materials Reviews, 55, 257-315, 2010.
• [6] Zhou, Y., Wen, B., Ma, Y., Melnik, R., Liu, X., First-principles studies of Ni-Ta intermetallic compounds, Journal of Solid State Chemistry, 187, 211-218, 2012.
• [7] Firstov, G.S., Koval, Y.N., Van Humbeeck, J., Ochin, P., Martensitic transformation and shape memory effect in Ni3Ta: A novel high-temperature shape memory alloy, Materials Science and Engineering A, 481-482, 590-593, 2008.
• [8] Koval, Y.N., Firstov, G.S., Nickel-tantalum-New object for investigation of martensitic transformations, Metallofizika i Noveishie Tekhnologii, 29(6), 815-821, 2007.
• [9] Ansara, I., Selleby, M., Thermodynamic analysis of the Ni-Ta system, Calphad, 18, 99-107, 1994.
• [10] Nash, A., Nash, P., The Ni-Ta (Nickel-Tantalum) system, Bulletin of Alloy Phase Diagrams, 5, 259-265, 1984.
• [11] Biffi, C.A., Agresti, F., Casati, R., Tuissi, A., Ni3Ta high temperature shape memory alloys: effect of B addition on the martensitic transformation and microstructure, Materials Today: Proceedings, 2S, 813-816, 2015.
• [12] Aballe, M., Ramaswamy, V., West, D.R.F., Intermetallic compound precipitation from solid solution in some Ni-Ta and Ni-Ta-Cr alloys, Journal of the Less-Common Metals, 39, 287-292, 1975.
• [13] Kosorukova, T., Firstov, G., Noël, H., Ivanchenko, V., Crystal structure changes in the Ni3Ta intermetallic compound, Chemistry of Metals and Alloys, 6, 196-199, 2013.
• [14] Yildiz, K., Thermally induced martensitic transformation and structural properties in Ni-Ta high-temperature shape memory alloys, The European Physical Journal Plus, 134, 11, 2019.
• [15] Larson, J.M., Taggart, R., Polonis, D.H., Ni8Ta in nickel-rich Ni-Ta alloys, Metallurgical and Materials Transactions B, 1, 485-489, 1970.
• [16] Kripyakevich, P.I., Pylaeva, E.N., Crystal structure of the compound Ta2Ni, Journal of Structural Chemistry, 3, 30-32, 1962.
• [17] Kosorukova, T.A., Firstov, G.S., Koval, Y.N. Van Humbeeck, J., Zhuravlev, B., Phase transformations and shape memory behavior in Ni3Ta-based intermetallics, Materials Today: Proceedings 2S, 793-796, 2015.
• [18] El-Bagoury, N., Comparative study on microstructure and martensitic transformation of aged Ni-rich NiTi and NiTiCo shape memory alloys, Metals and Materials International, 22, 468-473, 2016.
• [19] Kojima, H., Yoshizaki, H., Kaneno, Y., Semboshi, S., Hori, F., Saitoh, Y., Okamoto, Y., Iwase, A., Lattice structure transformation and change in surface hardness of Ni3Nb and Ni3Ta intermetallic compounds induced by energetic ion beam irradiation, Nuclear Instruments and Methods in Physics Research Section B, 372, 72-77, 2016.