International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In recent decades, increasing research in materials science and biomedical engineering has contributed to significant progress in biomedical metallic materials, some of which are titanium materials. The titanium used in the production of biomedical materials is usually alloyed with other elements such as niobium, molybdenum, copper and zirconium. Titanium alloys have become one of the most successful materials for biomedical applications, especially in orthopaedics and dentistry, due to their excellent biological, physical and mechanical properties. This article gives an overview of advanced characterization methods for titanium alloys such as light and electron microscopy, Xray diffraction, energy dispersive spectrometry, differential scanning calorimetry, differential thermal analysis, thermogravimetry and dynamic mechanical analysis. The article provides of the current status of the development of biomedical titanium alloys and use of advanced characterization methods, in the development of Ti-Cu alloys.

This work discusses the properties of 3D titanium alloys with wear-resistant coatings of hard alloy electrodes based on WC-TiB2-B4C and solder mass of Co-Ni-Cr-B-Fe-Si-C, produced by reaction electrospark processing (RESP) at positive and negative polarity. Through profilometric, metallographic, XRD, SEM, EDS and tribological methods, the complex influence of polarity and pulse energy on the topography, composition, properties, and wear characteristics of the coated surfaces was investigated. The differences in the coatings obtained with the two polarities were identified. Coatings with similar roughness and thickness were obtained, which can be changed by changing the modes for RESP within the limits Ra =2.5÷5μm, δ= 8÷40μm, with microhardness 8 to 14 GPa and 2-4 times higher wear resistance than that of the substrate. At RESP with negative polarity and pulse energy up to 0.04 J, the coatings have comparable characteristics and properties to those at positive polarity, but lower roughness, finer structure and lower coefficient of friction. These coatings can be successfully used to reduce roughness and surface defects and improve the wear resistance of 3D titanium alloys. The pulse energy and polarity of RESР, producing coatings with minimum roughness and maximum wear resistance, have been determined.

As a rule, parts that are made of titanium alloys are critical parts that can work in corrosive medium, accept alternating loads, have certain parameters of surface quality and surface layer. A finite-element simulation of a burnishing process of titanium alloy Ti-6Al-4V (an alloy that is widely used in medicine, as an example in endoprostheses) with/without ultrasonic loading at various processing speeds was carried out. It is established that when burnishing with ultrasonic vibrations of the tool, it is possible to obtain a qualitatively different picture of the distribution of residual stresses in the surface layer of the part. The features of the contact interaction of the tool with the workpiece surface were established for ultrasonic vibrations of the tool. For finite element simulation two types of ultrasonic vibrations were chosen (according to real ultrasonic tool): longitudinal and longitudinal-torsion vibrations. It is shown that the use of ultrasound can reduce the temperature of the deformation zone, which is extremely important when processing titanium alloys. It was also found that the use of metal-containing lubricant can improve the surface quality  arameters after ultrasonic burnishing.

Quantitative analysis of the phase composition of the Ti-Al-V-Mo-Zr system alloys was carried out during operation using the Thermo-Calc program (TCW5 version, TTTI3 database). Polythermal and isothermal cuts are plotted, design temperature values of liquidus, solidus and transition into β-field during heating are given. Regarding the titanium alloy of the Ti-Al-V-Mo-Zr system the effect of annealing temperature on the microstructure of the alloy as well as on the alloying elements content in α and β–phases was studied using the scanning electron microscopy method.

Quantitative analysis of the phase composition of the Ti-Al-V-Mo-Zr system alloys was carried out during operation using the Thermo-Calc program (TCW5 version, TTTI3 database). Polythermal and isothermal cuts are plotted, design temperature values of liquidus, solidus and transition into β-field during heating are given. Regarding the titanium alloy of the Ti-Al-V-Mo-Zr system the effect of annealing temperature on the microstructure of the alloy as well as on the alloying elements content in α and β–phases was studied using the scanning electron microscopy method.

The paper presents the application of modern computational approaches in determining the appropriate chemical composition of titanium alloys . Discusses three types of problems for the selection of the chemical composition of alloy at set requirements for mechanical properties . Tasks are solved in a different formulation of the target criteria . The proposed solutions are based on software model using approximation with artificial neural networks and genetic optimization algorithm.