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Low-modulus titanium alloys for biomedical use
Šalata, Kristián ; Preisler, Dalibor (advisor) ; Janeček, Miloš (referee)
Titanium alloys belong to a group of perspective biomaterials used for production of joint endoprotheses. In order to develop a biocompatible material with better mechanical properties, twelve alloys with 0.7 wt% of oxygen and different contents of Nb, Ta, Zr, Fe were fabricated. Microstructure and phase composition were studied by means of scanning electron microscopy, mechanical properties were determined by microhardness measurements and tensile testing. As follows from the microstructure analysis, only single alloy with composition Ti-20Nb-7Zr-0,7O (wt%) contained also the martensitic phase apart from the metastable phase. In case of other alloys we observed only phase. We found out that the microhardness of alloys gradually decreases with increasing content of -stabilizing elements until the solid solution is saturated. The high value of microhardness in case of alloys with low content of -stabilizing elements is thus considered as indirect proof of the presence of the brittle phase . Tensile tests showed that none of the alloys with increased hardness has undergone strain hardening. The interstitial oxygen atoms led to yield strengths of more than 1000 MPa for all investigated alloys. In some cases, the ultimate tensile strength was more than 1200 MPa. The most promising alloy for the...
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