Tolyatti State University, Tolyatti, Russia:

A. I. Kovtunov, Professor of the Chair for Welding, Metal Forming, Doctor of Technical Sciences, Associate Professor, e-mail: akovtunov@rambler.ru
D. I. Plakhotny, Engineer, Senior Lecturer of the Chair for Welding, Metal Forming, e-mail: d01125@mail.ru

Alloys based on titanium nickelides have high mechanical properties, as well as a set of special properties: shape memory effect, superelasticity, high level of damping and corrosion resistance, biocompatibility. To obtain titanium nickelides, various technologies are used: smelting in arc and induction vacuum furnaces, electrolysis of molten media, sintering, selfpropagating high-temperature synthesis, which are distinguished by high energy consumption of processes and significant cost. To reduce the cost of obtaining alloys based on titanium nickelide, a technology of double-arc melting in argon using electrode wires made of titanium and nickel was proposed, which makes it possible to obtain not only blanks and parts of the required shape from these alloys, but also deposited layers on the surface of finished products. The conducted studies of processes of titanium nickelides formation by double-arc melting showed that the chemical composition of samples is determined by modes of electric arc melting of electrode wires and, first of all, by the ratio of the feed rates of nickel and titanium wires. The nickel content in obtained samples varied within 34.1–60.1%. The structure of the samples was determined by the ratio of feed rates of electrode wires and was represented by phases: α(Ti); NiTi₂; NiTi. The structure based on NiTi₂ and Ti is formed when the ratio of the nickel wire feed rate to thetitanium wire feed rate is equal to 0.38. With the feed rate ratio in the range of 0.44–0.86, the structure of samples is represented by phases NiTi₂ + NiTi. A single-phase structure based on titanium nickelide (NiTi) during double-arc melting in an argon atmosphere is formed at the feed rate ratio of the order of 1–1.14 of nickel and titanium wires with the same diameter.

1. Khusainov М. А. Phase transitions in titanium nickelide alloys with shape memory effect. Part 2. Vestnik Novgorodskogo gosudarstvennogo universiteta. 2015. Vol. 86. No. 3. pp. 81–84.
2. Petrini L., Migliavacca F. Biomedical Applications of Shape Memory Alloys. Journal of Metallurgy. 2011. Vol. 2011. pp. 1–15.
3. Zao Y, Tan K, Zhou Y. et al. Materials for biological applications. Materials Science and Engineering. 2016. Vol. 59. pp. 193–202.
4. Tomi S., Rudolf R., Brunko M., Anžel I., Savi V., oli M. Response of monocyte-derived dendritic cells to rapidly solidified nickel-titanium ribbons with shape memory properties. European cells and materials. 2012. Vol. 23. pp. 58–81.
5. Lotkov А. I., Khachin V. N., Grishkov V. N., Meysner L. L., Sivokha V. P. Shape memory alloys. Vol. 2. Physical mesomechanics and computer design of materials. Novosibirsk : Nauka, 1995. pp. 202–213.
6. Otsuka K., Ren X. Physical metallurgy of Ti – Ni-based shape memory alloys. Progress in materials science. 2005. Vol. 50. No. 5. pp. 511–678.
7. Gudimova Е. Yu. Structural-phase states formed by pulsed electron-beam doping with tantalum of titanium nickelide surface layers, physical and mechanical properties of (TiNi – Ta)/TiNi layer composites: thesis of inaugaration of Dissertation … of Candidate Engineering Sciences. Tomsk : IFPM SO RAN, 2015. 225 p.
8. Shuytsev А. V. Structure and functional properties of TiNi intermetallic compound obtained by sintering calcium hydride powders: thesis of inaugaration of Dissertation … of Candidate Engineering Sciences. Moscow, 2016. 131 p.
9. Braun A, Westbrook J. Methods for producing intermetallics. Edited by I. I. Kornilov. Translated from English. Moscow : Metallurgiya, 1970. pp. 197–232.
10. Frenzel J. et. al. High quality vacuum induction melting of small quantities of NiTi shape memory alloys in graphite crucibles. Journal Aloys and Compounds. 2004. Vol. 385. P. 214–223.
11. Iitn V. I., Nayborodenko Yu. S. High-temperature synthesis of intermetallic compounds. Tomsk : TGU, 1989. 214 p.
12. Anikeev S. G. Structural-phase features and properties of porous-permeable alloys based on titanium nickelide obtained by high-temperature synthesis and sintering: Dissertation … of Candidate of Physical and Mathematical Sciences. Tomsk : Sibirian Physical-Technical Institute, 2016. 196 p.
13. Semistenov D. А., Kovtunov А. I., Plakhotny D. I. Double-arc surfacing of iron-aluminum alloys. Innovations of technical solutions in mechanical engineering and transport: collection of articles. Articles of the II All-Russian Scientific and Technical Conference for Young Scientists and Students with International Participation. Penza : Penza State Agricultural Academy. 2016. pp. 277–282.
14. Kovtunov А. I., Plakhotny D. I. Bochkarev А. G. Welding technology of permanent chill coatings. Liteyshchik Rossii. 2015. No. 4. pp. 26–28.
15. Krishtal М. М., Yasnikov I. S., Polunin V. I. et. al. Scanning electron microscopy and X-ray microanalysis in practical examples. Moscow : Tekhnosphera, 2009. 208 p.
16. GOST 9013–59. Metals. Method of measuring Rockwell hardness. Introduced: 01.01.1969. Moscow : Mezhgosudarstvenny standart, 1959.
17. Kolachev B. А., Elagin V. I., Livanov V. А. Metal science and heat treatment of non-ferrous metals and alloys. Moscow : MISIS, 2005. 432 p.
18. Konovalov А. V., Kurkin А. S., Makarov E. L., Nerovny V. М., Yakushin B. F. Theory of welding processes: textbook for universities. Edited by V. М. Nerovny. Мoscow: MGTU imeni N. E. Baumana, 2007. 752 p.
19. State diagrams of double metal systems: Handbook: In 3 volumes: vol. 1. Edited by N. P. Lyakishev. Moscow : Mashinostroenie, 1996. 992 p.
20. Blednova Zh. М., Stepanenko М. А. The role of shape memory alloys in modern mechanical engineering: scientific and educational course. Krasnodar : Kuban State Technological University, 2012. 69 p.