The continuous development of biomedical materials necessitates exploring new solutions to enhance implant performance. This study investigates the impact of titanium dioxide nanoparticles on calcium phosphate coatings applied to VT1-0 titanium substrates using micro-arc oxidation. Titanium, widely recognized for its excellent mechanical properties and compatibility, serves as an ideal substrate for implants. The coatings were synthesized in an electrolyte with varying titanium dioxide concentrations to examine their influence on surface morphology, wettability, roughness, hardness, and tribological characteristics. Characterization techniques, such as scanning electron microscopy, X-ray diffraction, and profilometry, were employed to analyze the coatings’ structural and mechanical properties. The results demonstrate that increasing titanium dioxide concentrations leads to enhanced uniformity, reduced pore sizes, and higher hardness. Furthermore, the coatings showed improved wear resistance and reductions in friction coefficients at optimal nanoparticle levels. The inclusion of titanium dioxide significantly enhances the mechanical and tribological performance of the calcium phosphate coatings, making them suitable for biomedical applications, especially in implants requiring long-term durability and enhanced compatibility.

The paper presents experimental results for a modified pulsed plasma thruster (PPT) with solid propellant, using a coaxial anode–cathode design. Graphite from pencil leads served as propellant, and a tungsten trigger electrode was tested to reduce carbonization effects. Experiments were performed in a vacuum chamber at 0.001 Pa, employing diagnostics such as discharge current/voltage recording, power measurement, ballistic pendulum, time-of-flight (TOF) method, and a Faraday cup. Current and voltage waveforms matched an oscillatory RLC circuit with variable plasma channel resistance. Key discharge parameters were measured, including current pulse duration/amplitude and plasma channel formation/decay dynamics. Impulse bit values, obtained with a ballistic pendulum, reached up to 8.5 μN·s. Increasing trigger capacitor capacitance reduced thrust due to unstable “pre-plasma” formation and partial pre-discharge energy loss. Using TOF and Faraday cup diagnostics, plasma front velocity, ion current amplitude, current density, and ion concentration were determined. Tungsten electrodes produced lower charged particle concentrations than graphite but offered better adhesion resistance, minimal carbonization, and stable long-term performance. The findings support optimizing trigger electrode materials and PPT operating modes to extend lifetime and stabilize thrust output.

The use of thermoplastic elastomers (TPE) in 3D printing technology enables the use of this technology to produce prototype seals with an unusual shape or design solution. Tribological tests were carried out on a pin-on-disc test stand. The influence of contact pressure and sliding velocity on the friction coefficient of the TPE-steel friction pair under mixed lubrication conditions was analyzed. Based on the obtained tribological test results, it was found that the coefficient of friction of the thermoplastic TPE elastomer on steel in the presence of hydraulic oil (mixed lubrication) at a sliding velocity below 1 m/s does not exceed μ = 0.25. The obtained friction coefficient values are comparable to the results for other elastomeric materials used for technical seals. It was found that the influence of contact pressure on the value of the friction coefficient in the tested friction pairs is varied and depends, for example, on the sliding velocity. It was recommended to carry out research on the assessment of durability (wear intensity) and structure (porosity) of the material in elements manufactured using 3D printing to obtain full knowledge of the possibility of using these materials in the area of technical aircraft seals.

The paper presents experimental results for a modified pulsed plasma thruster (PPT) with solid propellant, using a coaxial anode-cathode design. Graphite from pencil leads served as propellant, and a tungsten trigger electrode was tested to reduce carbonization effects. Experiments were performed in a vacuum chamber at 0.001 Pa, employing diagnostics such as discharge current/voltage recording, power measurement, ballistic pendulum, time-of-flight (TOF) method, and a Faraday cup. Current and voltage waveforms matched an oscillatory RLC circuit with variable plasma channel resistance. Key discharge parameters were measured, including current pulse duration/amplitude and plasma channel formation/decay dynamics. Impulse bit values, obtained with a ballistic pendulum, reached up to 8.5 μN·s. Increasing trigger capacitor capacitance reduced thrust due to unstable “pre-plasma” formation and partial pre-discharge energy loss. Using TOF and Faraday cup diagnostics, plasma front velocity, ion current amplitude, current density, and ion concentration were determined. Tungsten electrodes produced lower charged particle concentrations than graphite but offered better adhesion resistance, minimal carbonization, and stable long-term performance. The findings support optimizing trigger electrode materials and PPT operating modes to extend lifetime and stabilize thrust output.

This paper presents a detailed study of the fracture surfaces of 12Kh18N10T austenitic stainless-steel specimens subjected to short-term mechanical testing at various temperatures: 24°C, 350°C, and 450°C. The specimens for the study were fabricated from spent nuclear fuel of the BN-350 reactor. The research was conducted within the framework of a multi-level approach to physical mesomechanics, which allowed for a deeper understanding of the complex processes occurring in the material under different temperature regimes. In particular, a thorough analysis of the changes in the steel's plasticity with increasing test temperature was carried out, revealing a significant dependence of this parameter on the conditions of deformation localization. It was shown that the reduction in plasticity with increasing test temperature is associated with a quasi-uniform distribution of stresses in the zones of deformation localization. These zones of local stress concentration were caused by processes that led to an increase in the material's porosity, which, in turn, was due to accommodation processes of the rotational type. Thus, the study demonstrated the importance of considering local changes in the material's structure, which can significantly affect its mechanical properties under varying operating conditions. The obtained results may contribute to a deeper understanding of the processes occurring in austenitic steels used in extreme conditions and aid in the development of more reliable materials for use in nuclear and other high-stress systems.