Scientific results:
The deformation behavior of porous titanium nickelide alloys and spongy bone tissues under compression has been studied. A new approach has been developed for objective quantitative assessment of biomechanical compatibility of porous titanium nickelide alloy implants and bone tissues using experimental deformation curves and a calculated model of a hyperelastic medium using the finite element method. The calculated deformation curves were obtained for a hyperelastic model of a porous body obtained by the finite element method using 3-D reconstruction based on microtomography data of the porous alloy. The data on the corrosion fatigue of the porous TiNi alloy showed high fatigue strength, which is due to stress relaxation in the intermetallic phase of TiNi during reversible polymorphic martensitic transformation under the action of an external cyclic load. The structural and phase heterogeneity of the SHS-TiNi porous alloy is shown: inclusions in TiNi grains and on the surface; intergranular phases; structurally heterogeneous surface layer, are the features of SHS titanium nickelide. Using complex structural studies of fatigue fracture surfaces, it is shown that the multiphase and structural heterogeneity of the porous alloy is the cause of cracks. The deformation behavior of thin wires, titanium nickelide metal tricot and soft biological tissues under uniaxial tension is studied. Metal knitwear has a nonlinear hyperelastic mechanical behavior under single and cyclic stretching, unlike wire, which is characterized by superelastic deformation behavior. A new approach to objective quantitative assessment of biomechanical compatibility of titanium nickelide wire implants and soft tissues has been developed using experimental stress-strain curves and a calculated model of a hyperelastic medium using the finite element method. The calculated stress-strain curves have been obtained using the Bergström–Boyce numerical model for a hyperelastic medium taking into account the Mullins effect using the finite element method with. The structure of the matrix, inclusions, and surface layer of superelastic titanium nickelide wire has been precisely studied using transmission and scanning electron microscopy. It has been shown that TiNi wire consists of a matrix and a composite surface layer, which are formed during cyclic plastic deformation. The stress-strain state of titanium nickelide metallotrimming and the resistance of TiNi alloy wire and metallotrimming to fatigue in air and in a corrosive environment have been studied. The data on the corrosion fatigue of titanium nickelide wire and metallotrimming have shown high fatigue strength, which is due to stress relaxation in the TiNi intermetallic phase during reversible polymorphic martensitic transformation under external cyclic loading. The features of rheological feeding of titanium nickelide wire, consisting in the manifestation of the effect of superelasticity under tension and deformation reversibility, have been established, and the rheology of metallotrimming under quasi-static conditions has been investigated.
Implementation of research results:
The method of selecting implants based on rheological similarity has been implemented in the treatment algorithm of the Oncology Research Institute of the Tomsk National Research Medical Center of the Russian Academy of Sciences and the Research Institute of Medical Problems of the North (Krasnoyarsk). Experimental samples of implant materials for bone and soft tissue plastic surgery are undergoing preclinical trials at the Academician E.N. Meshalkin National Medical Research Center for Therapy and Preventive Medicine of the Ministry of Health of the Russian Federation (Novosibirsk); Ural State Medical University (Yekaterinburg); and the Kirov Military Medical Academy (St. Petersburg).
Organizational and infrastructural changes:
As a result of the project, a unique laboratory was created, on the basis of which world-class research is conducted, aimed at improving the quality of biomaterials used to replace bones and soft tissues.
Education and personnel occupational retraining:
In 2022, a program for the discipline was developed and implemented into the educational process as part of the implementation of the master's program: "Computer engineering of structures, biomechanical systems and materials".
In 2023, a program for the discipline was developed and implemented into the educational process as part of the implementation of the master's program: "Medical materials".
As a result of the project implementation, the following were defended: 2 dissertations for the degree of Doctor of Science, 2 dissertations for the degree of Candidate of Science, 9 master's theses, 5 bachelor's degrees.
A laboratory employee, under the supervision of a leading scientist, completed a scientific internship at the University of Florida on the topic "Patterns of the influence of surface phases on the fatigue strength of porous SHS-TiNi alloys" (Tampa, Florida, USA). In addition, the laboratory staff completed scientific internships under the supervision of leading Russian scientists at the Moscow Institute of Physics and Technology on the topic of "Synchrotron and Neutron Research Methods", at the National Research Center "Kurchatov Institute" on the topic of "In situ studies of the evolution of the phase composition of titanium nickelide wire in the mode of step-by-step stretching under a synchrotron beam" (Russia, Moscow), at the A.N. Frumkin Institute of Physical Chemistry and Electrochemistry of the Russian Academy of Sciences on the topic of "Study of corrosion resistance and chemical stability of medical alloys" (Russia, Moscow).
Cooperation:
- National Medical Research Center for Therapy and Preventive Medicine named after Academician E.N. Meshalkin of the Ministry of Health of the Russian Federation (Novosibirsk).
- Research Institute of Oncology of Tomsk National Research Medical Center of the Russian Academy of Sciences (Tomsk).
- Ural State Medical University (Yekaterinburg)
- Research Institute of Medical Problems of the North (Krasnoyarsk).
- Brandenburg Technical University of Cottbus-Senftenberg (Germany).
- School of Materials Science and Engineering, University of Ulsan (South Korea), Boramae Medical Center – Seoul National University Hospital (Южная Корея).
- School of materials science and engineering, Henan University of science and technology (КНР).
