Papers by Keyword: Titanium-Based Alloy

Abstract: The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.

Abstract: The Ti-21.8Nb-6Zr and Ti-19.7Nb-5.8Ta (at.%) shape memory alloys are thermomechanically treated by cold drawing and post-deformation annealing at 550-600°C forming a nanosubgrained structure in the β-phase. Cyclic mechanical testing using a “loading-unloading” mode with 2% tensile strain in each half-cycle reveals the non-perfect superelastic behavior of both alloys during the very first cycles of testing, which becomes perfect during further mechanocycling. The Young’s modulus of thermomechanically-treated alloys is low (about 45 GPa), and it decreases during mechanocycling (n=10 cycles) down to 25-35 GPa, approaching the Young’s modulus of cortical bone tissues. The Young’s modulus obtained in the 10th cycle is stable or changes only slightly during a further 40-day pause at room temperature and then during repeated mechanocycling. The residual strain per cycle, the transformation yield stress and the mechanical hysteresis decrease during mechanocycling. Subsequent to a 40-day pause at room temperature, they restore their initial values. Repeated mechanocycling is accompanied by a repeated decrease of these parameters.

Abstract: Recently, Ti-based metallic glasses aim at biomaterials with their high specific strength and superior corrosion resistance. Their high workability also shows a good performance for mass production under the energy saving environment. In this study, we started investigation of the design of Ti-based metallic glasses with the restricted alloying elements for biocompatibility and characteristic evaluation of the optimized Ti-based metallic glasses with higher glass forming ability for dental implants. These Ti-based metallic glasses do not contain Al, V and Ni elements which are well known to be neurotoxicity and cytotoxicity for human body. Current medical reports of impracticability by these elements have been a hot issue in biomaterials science. Newly designed Ti-based metallic glasses exhibit good performances. Especially, the optimized Ti-based metallic glass has high corrosion resistance with better passivity in a wide passivation range in simulated body fluids at 310K. In addition, biocompatibility of Ti-based metallic glass was also evaluated by cell culture in vitro. Excellent biocompatibility of Ti-based metallic glass show high potentials to be applied as biomaterials that necrosis of osteoblast (SaOS2) was not detected in this study.