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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.

This paper deals with production of hard metal by powder metallurgy and its effect on the environment. Hard metal is a composite material that consists of tungsten carbide as the hard refractory phase and cobalt or nickel as the soft metal binder phase. It cannot be produced by classical casting technology. Owing to its excellent properties, such as high hardness, wear and heat resistance etc., hard metal can be applied in a variety of industrial fields. Powder metallurgy is a technology for production of a wide range of materials as net-shape products from a compacted and sintered powders mixture. In this paper the impact of all stages of hard metal production by powder metallurgy on the environment is analysed. The presented analysis shows that production of hard metal by powder metallurgy has a minimum effect on the environment.

In order to improve the hold and function of dentures for the patient, various prostheses made of metal, mostly metal alloys, are used every day in dental practise. Cobalt-chromium alloys are usually the first choice because they have very good mechanical properties and satisfactory clinical conditions. Nowadays, laser welding is increasingly used in dental practise due to its numerous advantages over other technologies. In this work, therefore, six commercially available Co-Cr alloys were investigated. Three of them are used for metal-ceramic work, two for denture frameworks and one is suitable for both applications. They were joined by laser welding and subsequently analysed microscopically. Their mechanical properties were determined and statistically evaluated. The microhardness of the laser-welded alloys is in the range of 282–465 MPa in the weld zone and between 283 and 435 MPa in the heat-affected zone. The flexural strength of the laser-welded alloys is lower than the control group, but an alloy for the metal-ceramic work (I-BOND NF) shows very similar value. Furthermore, this alloy, together with two other metal-ceramic alloys, survived a maximum of cycles in dynamic tests. It was found that the laser method can be used for joining Co-Cr alloys while ensuring appropriate parameters that guarantee the quality of the dental work.

The influence of boron carbide and tungsten carbide on the apparent porosity, density, coercive force, hardness and microstructure of metal matrix composite of the Ferro-TiC type, is presented in this paper. The samples of investigated steel/titanium carbide composite were produced by powder metallurgy process, i.e. by powders mixing and compacting followed by sintering in the vacuum furnace. According to the results, steel/titanium carbide composite materials with addition up to 11.9 vol.% of boron carbide are interesting to detailed investigation as well as materials having more than 17.2 vol.% of tungsten carbide because these compositions show significant changes in hardness and coercive force values.

In this paper, thermomechanical processing of niobium microalloyed steel was performed with the purpose of determining the interaction between niobium precipitates and dislocations, as well as determining the influence of the temperature of final deformation on the degree of precipitation and dislocation density. Two variants of thermomechanical processing with different final rolling temperatures were carried out. Samples were studied using electrochemical isolation with an atomic absorption spectrometer, transmission electron microscopy, X-ray diffraction analysis, and universal tensile testing with a thermographic camera. The results show that the increase in the density of dislocations before the onset of intense precipitation is insignificant because the recrystallization process takes place simultaneously. It increases with the onset of strain-induced precipitation. In this paper, it is shown that niobium precipitates determine the density of dislocations. The appearance of Lüders bands was noticed as a consequence of the interaction between niobium precipitates and dislocations during the subsequent cold deformation. In both variants of the industrial process performed on the cold deformed strip, Lüders bands appeared.