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Implant surface properties of Ti6Al4V alloy that is currently used as a biocompatible material because of a variety of unique properties can be improved by a self-organized TiO2 layer. The TiO2 nanotubes forming on the titanium-based materials is a relatively recent technology for the surface properties modification and represents pronounced potential in promoting cell adhesion, proliferation, and differentiation that facilitate an implant osseointegration. This work focuses on the influence of surface treatment quality and anodic oxidation parameters on the structure features and properties of TiO2 nanotube coatings. The nanotubes were formed on Ti6Al4V alloy substrates by simultaneous surface oxidation and controlled dissolving of an oxide film in the presence of fluorine ions. The anodization process on ground or polished samples was performed at experimental condition of 30 V for 1 h. The selected anodized samples were heat treated for 2 h at 500 °C under flowing argon. All samples were characterized by scanning electron microscopy, X-ray diffraction analysis, and Raman spectroscopy. The corrosion rate in physiological solution reached 0.0043, 0.0182, and 0.0998 mm per year for the samples in polished and not-anodized, as-anodized, and anodized-heat treated conditions, respectively.

Tensile deformation behaviour of ferritic-pearlitic steel was studied by the digital image correlation (DIC) method. Room temperature tensile tests were carried out at an initial strain rate of 1 × 10 −3 s −1 up to a defined elongation or fracture. The elongation and contraction were measured on the surface of cylindrical tensile specimens with random speckle pattern using stereo CCD camera system. The DIC elongation data were related to the data measured by an extensometer touching the specimens. The data from the DIC method were used for calculations of true stress-true strain tensile curves, strain hardening exponents and work hardening rates during uniform deformation up to the onset of plastic instability as well as non-uniform deformation during necking. Numerical simulations of strain fields within the gauge region of the specimens using finite element method were validated by the experimental data from the DIC method.

The comparative analysis of mechanical properties using a digital image correlation by Vic 2D software was performed for two types of high-strength materials. The strain analysis during tensile tests was carried out on the cylinder tensile specimens of 34CrMo4 steel and IN 738LC superalloy. Both materials showed similar strength but different ductility. While the 34CrMo4 steel showed typical necking of tensile specimens with ductile fracture surfaces, cracking of the IN 738LC became without necking, and the fracture morphology displayed mixed feature with ductile dimples or quasi-cleavage areas and cracked carbides. Microhardness measurements completed metallographic and fractographic studies of tensile samples.

A Ti–25Nb–13Ta–5Zr alloy was produced and studied in this work, and plates and wires were made from this alloy. It is shown that the Ti–25Nb–13Ta–5Zr alloy has the required mechanical properties and a β-crystal phase. Microstructures were present on the surface of the alloy with a height of several hundred nm, located at a distance of 1.5–2 μm from each other. Ti–25Nb–13Ta–5Zr was superior to nitinol in terms of the formation of long-living reactive protein species and the generation of reactive oxygen species. Cell cultivation on Ti–25Nb–13Ta–5Zr alloy surfaces revealed a significant mitotic index (2%) and a small number of nonviable cells (<5%). The cells were actively attached and spread over the alloy. The biocompatibility of Ti–25Nb–13Ta–5Zr was verified by experiments on the implantation of the alloy in the form of plates and coiled wires. The surface morphology of the specimens after biological trials was not significantly altered. The experimental data we obtained suggest that Ti–25Nb–13Ta–5Zr is suitable for potential applications in biology and medicine.

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In this work, the Ti6Al4V specimens produced by selective laser melting were mechanically tested in non-heat treated condition and fracture surface features were compared with this one of the material prepared using conventional casting and forging. The results of the fractography observation for both types of the samples were explained on the base of the microstructure analysis. The fracture surface of selective laser melted specimens showed more brittle feature that was in relation with the microstructure composed almost fully of martensite as opposed to conventionally prepared alloy with bimodal (α + β) microstructure and more ductile character of fracture surfaces.