Titanium-based Biomaterials

U odnosu na legure na bazi kobalt-kroma i nehrđajuće čelike, titan i legure na bazi titana našle su široku primjenu u biomedicini, gdje se zbog svojih izvrsnih svojstava upotrebljavaju kao implantati, ali zbog visoke cijene njihove proizvodnje još uvijek nemaju širu upotrebu. Neka od bitnih svojstava su: izvrsna biokompatibilnost, dobra mehanička svojstva i oseointegracija te otpornost na koroziju. Uz predstavljanje biomedicinskih materijala koji se najčešće upotrebljavaju, ovaj članak prikazuje razvoj biomaterijala na bazi titana i njihovu biomedicinsku primjenu. Biomaterijali se obično upotrebljavaju u biomedicini za popravak, zamjenu ili regeneraciju tjelesnih tkiva. S obzirom na to da je poznat sve veći broj neuspjelih implantacija uzrokovanih patogenom bakterijskom infekcijom, među funkcijama koje bi se mogle dodati biomaterijalima je antibakterijsko djelovanje, koje je od velike važnosti. U novije vrijeme antibakterijske metalne legure pokazale su velik potencijal kao nova vrsta biomedicinskog materijala.Compared to cobalt-chromium and stainless steel based alloys, titanium and titanium based alloys have found wide application in biomedicine, and are used as biomedical implants due to their excellent properties, but are yet to be widely used due to the high cost of their production. Their most important properties include: excellent biocompatibility, good mechanical properties, osseointegration, and corrosion resistance. In addition to presenting some commonly used biomedical materials, this article gives an overview of the development of titanium biomaterials and their biomedical applications. Biomaterials are widely used in biomedicine to repair, replace or regenerate body tissue. Given that an increasing number of failed implantations caused by pathogenic bacterial infection are known, among the functions that could be added to biomaterials is antibacterial action, which is of great importance. Recently, antibacterial metal alloys have shown great potential as a new type of biomedical material

Microhardness dependence of Ti-Zr alloys on time and temperature of sintering

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

Analysis of the densification of a biomedical titanium alloy produced by powder metallurgy

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

Analysis of the densification of a biomedical titanium alloy produced by powder metallurgy

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

Effect of sintering time and temperature on the microhardness of titanium-zirconium alloy

Titanium and titanium alloys have been widely used in medicine as implant materials for the last 50 years. The reason for this could be found in a unique combination of biocompatibility and strength of these alloys. The main advantage of titanium is the ability to bind to bone and grow into the implant. Due to the high cost of production, titanium is not used in large quantities, and therefore research are focused on finding new, more economical alloys. For these reasons, the aim of this paper is to analyze the effect of powder metallurgy process parameters in the production of titanium alloy containing 20% zirconium. Starting elemental powders were a ball milled and then compacted using the hydraulic press. Sintering process was performed under the different values of time and temperature. Starting powders were characterized using the scanning electron microscope. Porosity was analyzed using the light microscope. It was found that it could be decreased by increase in sintering temperature. Microhardness of polished sintered samples was determined by Vickers method. Results showed that higher microhardness values were obtained in samples sintered at higher temperature. Finally, results show that titanium-zirconium alloy produced by this route of powder metallurgy could be potentially used in a biomedicine

Influence of corrosive media on elution of titanium alloy metal ions

The superior mechanical properties of titanium alloys have singled out this type of alloy as an essential material for various applications, especially in the field of biomedicine. Due to the growing demand for permanent implants, it has become necessary to accelerate the growing development research of biomaterials, and thus titanium alloys. In this research, influence of corrosive media on elution of titanium-chromium- niobium alloy of new chemical composition, Ti- 10Cr-10Nb, was investigated. It was produced by melting and casting in an electric arc furnace in argon atmosphere. The alloy was tested in three different media (saline, saliva and sweet carbonated beverage) at two temperatures (37 ˚C and 39 ˚C), in the same time interval. The polished surface of the samples was observed by a light microscope and Vickers hardness was measured as well. Conductivity and pH of corrosive media were measured before and after the elution. Concentrations of eluted metal ions were determined by inductively coupled plasma spectroscopy. The obtained results showed dependence of chromium ions elution on temperature as well as on type of corrosive media

Influence of corrosive media on elution of titanium alloy metal ions

The superior mechanical properties of titanium alloys have singled out this type of alloy as an essential material for various applications, especially in the field of biomedicine. Due to the growing demand for permanent implants, it has become necessary to accelerate the growing development research of biomaterials, and thus titanium alloys. In this research, influence of corrosive media on elution of titanium-chromium- niobium alloy of chemical composition Ti10Cr-10Nb was investigated. It was produced by melting and casting in an electric arc furnace in argon atmosphere. The alloy was tested in three different media (physiological solution, saliva and sweet carbonated beverage) at two temperatures (37 C and 39 C) in the same time interval. Concentrations of eluted metal ions were determined by inductively coupled plasma spectroscopy. The surface of the samples was observed by a light microscope and Vickers hardness was measured as well. pH of corrosive media was measured before and after the elution. The obtained results showed dependence of eluted metal ions on temperature as well as on type of corrosive media

Application of characterisation methods in the development of biomedical titanium alloys

Biomaterials are becoming an increasingly important research topic over time as they are used to replace parts and functions of the human body, helping to improve the quality of human life. Titanium alloys are particularly important for the development of new biomaterials. Commercial pure titanium and its alloys are used as essential structural biomaterials in the manufacture of implants due to their excellent biocompatibility, good corrosion resistance and mechanical strength. However, studies have shown that aluminum and vanadium ions are released in alloys such as Ti-6Al-4V, which can cause health problems over time. Because of the problems that occur, researchers are working to improve the properties of titanium alloys by adding new elements. In most cases, different metals are added to titanium and it is known that with the presence of different metals, the properties of titanium also change. All biomedical titanium alloys must undergo various testing procedures before they can be used. The article describes the characterisation methods used in the development of titanium alloys, such as: light and scanning electron microscopy, energy-dispersive spectrometry, X-ray diffraction analysis, differential scanning calorimetry, differential thermal analysis. The reliability of the results depends on the methods used and the avoidance of errors in the characterisation of biomedical alloys in order to reach better conclusions and produce alloys of the highest quality desirable for use in the human body

Influence of corrosive media on elution of titanium alloy metal ions

The superior mechanical properties of titanium alloys have singled out this type of alloy as an essential material for various applications, especially in the field of biomedicine. Due to the growing demand for permanent implants, it has become necessary to accelerate the growing development research of biomaterials, and thus titanium alloys. In this research, influence of corrosive media on elution of titanium-chromium- niobium alloy of chemical composition Ti10Cr-10Nb was investigated. It was produced by melting and casting in an electric arc furnace in argon atmosphere. The alloy was tested in three different media (physiological solution, saliva and sweet carbonated beverage) at two temperatures (37 C and 39 C) in the same time interval. Concentrations of eluted metal ions were determined by inductively coupled plasma spectroscopy. The surface of the samples was observed by a light microscope and Vickers hardness was measured as well. pH of corrosive media was measured before and after the elution. The obtained results showed dependence of eluted metal ions on temperature as well as on type of corrosive media

Microhardness dependence of Ti-Zr alloys on time and temperature of sintering

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