National Research Tomsk State University, Tomsk, Russia:

A. A. Kozulin, Candidate of Physical and Mathematical Sciences, Senior Researcher, kzln2015@yandex.ru
A. V. Vetrova, Post-Graduate Student, Engineer-Researcher
Yu. F. Yasenchuk, Candidate of Physical and Mathematical Sciences, Associate Professor, Senior Researcher, yayuri2008@gmail.com
M. A. Kovaleva, Student, Laboratory Assistant

Samples of porous NiTi were obtained by the method of self-propagating high-temperature synthesis. The mechanical characteristics of the porous ones were studied by quasi-static compression. When the samples of porous titanium nickelide were subject to quasi-static compression, the deformation was of an elastic-plastic nature. Three characteristic types of the fracture surface under quasi-static compression of the porous SHS – TiNi alloy were identified: 1) ductile fracture of the austenite phase in the form of a cup relief, 2) brittle fracture accompanied by the formation of cleavage steps, 3) large areas of plastic shear deformation, on which cups and cleavage facets were nucleated. To determine the anisotropy of the porous TiNi alloy properties, the volume of the porous sample was simulated, and estimated calculations were carried out. Based on the results of reconstructing 3D neutron high resolution tomography of the porous volume of titanium nickelide and the numerical parameters of the model porous medium, an algorithm was developed for obtaining a solid-state 3D model of the porous framework for using in finite element calculations. The studied porous titanium nickelide alloy, as well as spongy bone tissues, was shown to have orthotropic elastic properties conditioned by the geometric features of the porous framework. The effective moduli of elasticity and shear for the porous volume of the material were determined. The calculation results of the elastic moduli for the studied model of porous titanium nickelide numerically agree with the results obtained by compressing the samples of porous TiNi. The porous TiNi alloy under uniaxial compression was established to be destroyed under the action of tangential shear stresses at an angle of 45 degrees to the direction of uniaxial compression.

The research was carried out with financial support of the Russian Science Foundation under the Grant No. 22-72-10037, https://rscf.ru/project/22-72-10037/.

1. Grunsven W., Goodall R., Reilly G. C. Highly Porous Titanium Alloy: Fabrication and Mechanical Properties. Journal of Biomechanics. Vol. 45. S339.
2. Uzunyan N. A., Olesova V. N., Lebedenko I. Yu., Khafizov R. G., Filonov M. R., Ivanov A. S. Experimental Study of The Dynamics of Osseointegration of the Dental Implants of Superelastic Titanium Alloys. Rossiyskiy Vestnik Dentalnoy Implantologii. 2018. Vol. 39-40, Iss. 1-2. pp. 8–11.

3. Marchenko E., Yasenchuk Yu., Avdeeva D., Baigonakova G., Gyunter S., Iuzhakova M. Deformation Behavior, Fatigue and Fracture Surface Microstructure of Porous Titanium Nickelide. Micro and Nanosystems. 2021. Vol. 13, Iss. 4. pp. 442–447.
4. Yasenchuk Yu. F., Marchenko E. S., Baigonakova G. A., Gyunter S. V., Kokorev O. V., Gunther V. E., Chekalkin T. L., Topol`nickij E. B., Obrosov A., Kang J.-H. Study on Tensile, Bending, Fatigue, and In Vivo Behavior of Porous SHS-TiNi Alloy Used as a Bone Substitute. Biomedical Materials. 2021. Vol. 6, Iss. 2. 021001
5. Uzunyan N. A. Substantiation of the Use of New Domestic Superelastic Titanium Alloys in Dental Implantology (Experimental Clinical Study). A Dissertation … Doctor of Medical Sciences. Moscow, 2019. 179 p.
6. Gunther V. E., Yasenchuk Yu. F., Gyunter S. V., Marchenko E. S., Iuzhakov M. M. Biocompatibility of Porous SHSTiNi. Materials Science Forum. 2019. Vol. 970. pp. 320–327.
7. Kang J., Dong E., Li D., Dong S., Zhang C., Wang L. Anisotropy Characteristics of Microstructures for Bone Substitutes and Porous Implants with Application of Additive Manufacturing in Orthopaedic. Materials & Design. 2020. Vol. 191. 108608.
8. Gómez S., Vlad M. D., López J., Fernández E. Design and Properties of 3D Scaffolds for Bone Tissue Engineering. Acta Biomaterialia. 2016. Vol. 42. pp. 341–350.
9. Marchenko E. S., Yasenchuk Yu. F., Gyunter S. V., Baigonakova G. A., Gunther V. E., Chekalkin T. L., Weiss S., Obrosov A., Dubovikov K. M. Structural-Phase Surface Composition of Porous TiNi Produced by SHS. Materials Research Express. 2019. Vol. 6, Iss. 11. 1165b1.
10. Smolin I. Yu., Makarov P. V., Eremin M. O., Matyko K. S. Numerical Simulation of Mesomechanical Behavior of Porous Brittle Materials. Procedia Structural Integrity. 2016. Vol. 2. pp. 3353–3360.
11. Bruno G., Efremov A. M., Levandovskyi A. N., Clausen B. Connecting the Macro- and Microstrain Responses in Technical Porous Ceramics: Modeling and Experimental Validations. Journal of Materials Science. 2011. Vol. 46, Iss. 1. pp. 161–173.
12. Roberts A., Garboczi E. Elastic Properties of Model Porous Ceramics. Journal of the American Ceramic Society. 2000. Vol. 83, Iss. 12. pp. 3041–3048.
13. Torquato S. Random Heterogeneous Media: Microstructure and Improved Bounds on Elastic Properties. Applied Mechanics Reviews. 1991. Vol. 44, Iss. 2. pp. 37–76.
14. Konovalenko I. S., Smolin A. Y., Korostelev S. Y., Psakh’e S. G. Dependence of the Macroscopic Elastic Properties of Porous Media on the Parameters of a Stochastic Spatial Pore Distribution. Technical Physics. 2009. Vol. 54, Iss. 5. pp. 758–761.
15. Smolin I. Yu., Eremin M. O., Makarov P. V., Evtushenko E. P., Kulkov S. N., Buyakova S. P. Brittle Porous Material Mesovolume Structure Models and Simulation of their Mechanical Properties. AIP Conference Proceedings. 2014. Vol. 1623. 595.
16. Makarov P. V. Evolutionary Nature of Destruction of Solids and Media. Physical Mesomechanics. Vol. 10, Iss. 3–4. pp. 134–147.
17. Makarov P. V. Mathematical Theory of Evolution of Loaded Solids and Media. Physical Mesomechanics. 2008. Vol. 11, Iss. 5–6. pp. 213–227.
18. Kostandov Y. A., Makarov P. V., Eremin M. O., Smolin I. Y., Shipovskii, I. E. Fracture of Compressed Brittle Bodies with a Crack. International Applied Mechanics. 2013. Vol. 49, Iss. 1. pp. 95–101.
19. Medical Materials and Implants with Shape Memory. In 14 vols. Ed. by Gyunter V. E. Tomsk: NII Meditsinskikh Materialov i Implantov s Pamyatyu Formy SFTI pri TGU, 2011. 533 p.
20. Guo Z., Xie H., Dai F., Qiang H., Rong L., Chen P., Huang F. Compressive Behavior of 64% Porosity NiTi Alloy: An Experimental Study. Materials Science and Engineering: A. 2009. Vol. 515, Iss. 1-2. pp. 117–130.
21. Barrabés M., Sevilla P., Planell J. A., Gil F. J. Mechanical Properties of Nickel–Titanium Foams for Reconstructive Orthopaedics. Materials Science and Engineering: C. 2008. Vol. 28, Iss. 1. pp. 23–27.
22. 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.
23. Resnina N., Belyaev S., Voronkov A., Gracheva A. Mechanical Behaviour and Functional Properties of Porous Ti-45 at.% Ni Alloy Produced by Self-Propagating High-Temperature Synthesis. Smart Materials and Structures. 2016. Vol. 25, Iss. 5. 055018.
24. Resnina N., Belyaev S., Voronkov A. Functional Properties of Porous Ti-48.0 at.% Ni Shape Memory Alloy Produced by Self-Propagating High-Temperature Synthesis. Journal of Materials Engineering and Performance. 2018. Vol. 27, Iss. 3. pp. 1257–1264.
25. Kaya M., Orhan N., Tosun G. The Effect of the Combustion Channels on the Compressive Strength of Porous NiTi Shape Memory Alloy Fabricated by SHS as Implant Material. Current Opinion in Solid State and Materials Science. 2010. Vol. 14, Iss. 1. pp. 21–25.
26. Li Y.-H., Rong L.-J., Li Y.-Y. Compressive Property of Porous NiTi Alloy Synthesized by Combustion Synthesis. Journal of Alloys and Compounds. 2002. Vol. 345, Iss. 1-2. pp. 271–274.