National Research Tomsk State University, Tomsk, Russia:

A. A. Shishelova, Undergraduate Student, e-mail: arina.sh9906@gmail.com
E. S. Marchenko, Head of the Superelastic Biointerfaces Laboratory, Associate Professor, Doctor of Physics and Mathematics Sciences
G. A. Baygonakova, Senior Researcher, Candidate of Physics and Mathematics Sciences
Yu. F. Yasenchuk, Senior Researcher

Titanium nickelide alloys are widely used as implant material. Porous TiNi alloys are normally fabricated by self-propagating high-temperature synthesis in argon medium. Air present in the reaction chamber may lead to an increased concentration of oxynitrides at the surface of the porous TiNi alloy and thus raise its cytocompatibility. The paper examines the effect of nitrogen on the functional properties, phase composition and hemolytic activity of porous TiNi alloy. It was found that the presence of interstitial phases – such as Ti₄Ni₂N(O) — has no impact on the nature of martensitic transformations caused by the changing temperature. A single-phase martensitic transformation B2↔B19' takes place in the porous TiNi alloy synthesized in nitrogen medium with some oxygen present. Having studied the shape memory effect of the porous TiNi alloy, the authors conclude that the manifestation of inelastic reversible strain of the porous alloy may be constrained by the structural inhomogeneity of the matrix of porous specimens, as well as due to the emergence of brittle interstitial phases of Ti2Ni + Ti₄Ni₂N(O) and TiNi₃ but cannot be completely suppressed by them. Porous TiNi alloys synthesized in nitrogen medium have a lower hemolytic index and a higher cytocompatibility.
This research was carried out as part of Governmental Assignment of the Ministry of Education and Science of Russia; Project No. FSWM-2020-0022.

1. Yuan B., Zhu M., Chung C. Y. Biomedical porous shape memory alloys for hard-tissue replacement materials. Materials. 2018. Vol. 11, Iss. 9. 1716.
2. Bansiddhi A., Sargeant T. D., Stupp S. I., Dunand D. C. Porous NiTi for bone implants: a review. Acta Biomaterialia. 2008. Vol. 4, Iss. 4. pp. 773–782.
3. Yasenchuk Y., Marchenko E., Gunther V., Radkevich A. et al. Biocompatibility and clinical application of porous TiNi alloys made by self-propagating high-temperature synthesis (SHS). Materials. 2019. Vol. 12, Iss. 15. 2405.
4. Che H. Q., Ma Y., Fan Q. C. Investigation of the mechanism of self-propagating high-temperature synthesis of TiNi. Journal of Materials Science. 2011. Vol. 46, Iss. 8. pp. 2437–2444.
5. Wisutmethangoon S., Denmud N., Sikong L. Characteristics and compressive properties of porous NiTi alloy synthesized by SHS technique. Materials Science and Engineering: A. 2009. Vol. 515, Iss. 1-2. pp. 93–97.
6. Novák P., Mejzlíková L., Michalcová A., Capek J. et al. Effect of SHS conditions on microstructure of NiTi shape memory alloy. Intermetallics. 2013. Vol. 42. pp. 85–91.
7. Resnina N., Rubanik V. (Jr.), Rubanik V., Kulak M. et al. Influence of the Ar pressure on the structure of the NiTi foams produced by self-propagating high-temperature synthesis. Materials Letters. 2021. Vol. 299. 130047.
8. Jin S., Zhang Y., Wang Q., Zhang D., Zhang S. Influence of TiN coating on the biocompatibility of medical NiTi alloy. Colloids and Surfaces B: Biointerfaces. 2013. Vol. 101. pp. 343–349.

9. Datta S., Das M., Balla V. K., Bodhak S., Murugesan V. K. Mechanical, wear, corrosion and biological properties of arc deposited titanium nitride coatings. Surface and Coatings Technology. 2018. Vol. 344. pp. 214–222.
10. Hariprasad S., Ashfaq M., Arunnellaiappan T., Harilal M., Rameshbabu N. Role of electrolyte additives on in-vitro corrosion behavior of DC plasma electrolytic oxidization coatings formed on Cp – Ti. Surface and Coatings Technology. 2016. Vol. 292. pp. 20–29.
11. Sugisawa H., Kitaura H., Ueda K., Kimura K. et al. Corrosion resistance and mechanical properties of titanium nitride plating on orthodontic wires. Dental Materials Journal. 2018. Vol. 37, Iss. 2. pp. 286–292.
12. Naji Q. K., Salman J. M., Dawood N. M. Investigations of structure and properties of layered bioceramic HA/TiO₂ and ZrO₂/TiO₂ coatings on Ti – 6 Al – 7 Nb alloy by micro-arc oxidation. Materials Today: Proceedings. 2022. Vol. 61. pp. 786–793.
13. Pana I., Braic V., Dinu M., Mouele E. S. M. et al. In vitro corrosion of titanium nitride and oxynitride-based biocompatible coatings deposited on stainless steel. Coatings. 2020. Vol. 10, Iss. 8. 710.
14. Karjalainen P. P., Nammas W. Titanium-nitride-oxide-coated coronary stents: insights from the available evidence. Annals of Medicine. 2017. Vol. 49, Iss. 4. pp. 299–309.
15. Qiu A. T., Liu L. J., Wei P., Lu X. G., Li C. H. Calculation of phase diagram of Ti – Ni – O system and application to deoxidation of TiNi alloy. Transactions of Nonferrous Metals Society of China. 2011. Vol. 21, Iss. 8. pp. 1808–1816.
16. Balogh Z., Schmitz G. Diffusion in metals and alloys. Physical Metallurgy. Elsevier, 2014. pp. 387–559.
17. Kaya M., Orhan N., Kurt B., Khan T. I. The effect of solution treatment under loading on the microstructure and phase transformation behavior of porous NiTi shape memory alloy fabricated by SHS. Journal of Alloys and Compounds. 2009. Vol. 475, Iss. 1-2. pp. 378–382.
18. Jiang H. C., Rong L. J. Ways to lower transformation temperatures of porous NiTi shape memory alloy fabricated by self-propagating high-temperature synthesis. Materials Science and Engineering: A. 2006. Vol. 438. pp. 883–886.
19. Ulianova N. Yu., Kurilenko L. N., Shamova O. V., Orlov D. S., Golubeva O. Yu. Hemolytic activity and sorption capacity of Beta zeolite nanoparticles. Glass Physics and Chemistry. 2020. Vol. 46, No. 2. pp. 174–183.