The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of ε_tot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.

Super-Duplex Stainless Steeles (SDSS) proved an excellent potential for its use in many chemical and offshore applications due to their both high mechanical properties and a high corrosion resistance in chloride ion solutions. This study evaluates the influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy. The influence of ageing treatment on microstructural features was analysed by SEM-EBSD (Scanning Electron Microscopy - Electron Backscatter Diffraction) technique, while on mechanical properties by tensile and impact testing techniques. The obtained results show that for the short duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/γ grains boundary by the δ → σ precipitation, while for long duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/δ grains boundary, or in other favourable nucleation sites, due to the eutectoid decomposition δ → σ + γ2. Experimental data showed that at low temperatures, i.e. 780 °C, in order to induce the precipitation of σ-phase, the minimum incubation time is situated close to 20 min, and that increasing treatment temperature decreases the minimum incubation time, with at 850 °C and 920 °C the σ-phase being firstly detected at 5 min. The σ-phase precipitation shows the highest precipitation kinetics at 850 °C, when the maximum weight-fraction is obtained for each treatment duration when compared with ageing treatments performed at 780 °C and 920 °C. All presented data brings valuable insight into the σ-phase precipitation phenomena and its influence on UNS S32750 SDSS alloy’s exhibited mechanical properties and, also, can provide researchers and industrial steel processors a guide regarding the selection of optimal ageing treatment parameters to avoid/minimise the embrittlement induced by the precipitation of deleterious σ-phase.

The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg-10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD—X-ray diffraction, and SEM—scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised temporary biodegradable implants of magnesium alloys. The compression tests show results closer to those of human bones compared to other potential metallic alloys. The applied corrosion test shows result comparable with that of the commercial magnesium alloy ZK60.

The influence of complex thermo-mechanical processing (TMP) on the mechanical properties of a Ti-Nb-Zr-Fe-O bio-alloy was investigated in this study. The proposed TMP program involves a schema featuring a series of severe plastic deformation (SPD) and solution treatment (STs). The purpose of this study was to find the proper parameter combination for the applied TMP and thus enhance the mechanical strength and diminish the Young’s modulus. The proposed chemical composition of the studied β-type Ti-alloy was conceived from already-appreciated Ti-Nb-Ta-Zr alloys with high β-stability by replacing the expensive Ta with more accessible Fe and O. These chemical additions are expected to better enhance β-stability and thus avoid the generation of ω, α’, and α” during complex TMP, as well as allow for the processing of a single bcc β-phase with significant grain diminution, increased mechanical strength, and a low elasticity value/Young’s modulus. The proposed TMP program considers two research directions of TMP experiments. For comparisons using structural and mechanical perspectives, the two categories of the experimental samples were analyzed using SEM microscopy and a series of tensile tests. The comparison also included some already published results for similar alloys. The analysis revealed the advantages and disadvantages for all compared categories, with the conclusions highlighting that the studied alloys are suitable for expanding the database of possible β-Ti bio-alloys that could be used depending on the specific requirements of different biomedical implant applications.