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

New types of materials have been developed for years, including titanium-based alloys, which have the potential for various applications. Due to the combination of their very good mechanical properties with outstanding corrosion resistance and excellent biocompatibility, titanium alloys are developing into materials that can be used in aerospace, automotive, energy systems and especially in medicine. A fundamental understanding of the phase transformations that occur at high temperatures in all these cases, especially during cooling from elevated temperatures, is necessary to achieve optimal mechanical properties of titanium alloys. It is known that the mechanical properties of titanium alloys depend on a significant extent upon the microstructure. Therefore, it is very important to understand the nature of the phase transformations that occur under different heat treatment conditions the leads to microstructure development of titanium alloys microstructure. The aim of this article is to review the current state of knowledge and previous research and to point out some of the most interesting phase transformations of titanium alloys.

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.

Commonly used metallic biomaterials are titanium and its alloys, cobalt-based alloys and 316L stainless steel. Titanium alloys are reference materials in biomedical applications due to their desirable properties such as excellent mechanical properties and good biocompatibility. Since presence of different metals can significantly alter the properties of titanium it is usually alloyed with other metals, including the zirconium. In this work Ti-20Zr was prepared by powder metallurgy by mixing the powders in a ball mill and sintering in a tube furnace under argon atmosphere. Microscopic analysis with the light microscope showed that the porosity decreased with increasing temperature and sintering time. Scanning electron microanalysis with energy-dispersive spectrometry showed the two-phase microstructure of the sintered alloy. Microhardness was determined by Vickers method. A longer sintering time and a higher sintering temperature resulted in higher microhardness values.

Titanium as a raw material for production is very expensive due to its high price and the complex production process. One of the successful alternatives for the production of titanium alloys and final products is powder metallurgy technology. In this work, a Ti-20Zr alloy for biomedical applications was produced using the powder metallurgy process. The density values determined for the compacts depend on the compression pressure. Namely, the compressibility of the powder mixture increases with increasing compaction pressure. A higher sintering temperature as well as a longer sintering time are more favourable to obtain higher values for the sintered density. Similarly, the compression coefficient is lower for samples compacted at higher pressure, while its value increases with increasing sintering temperature. The volume change in the volume of the sample is more pronounced after sintering at higher temperature and shorter time.