At the interface of thin film development and powder metallurgy technologies, this study aims to characterise the mechanical properties, lattice constants and phase formation of Ti-Nb alloys (8–30 at.%) produced by different manufacturing methods, including conventional powder metallurgy (PM), mechanical alloying (MA) and high power impulse magnetron sputtering (HiPIMS). A central aspect of this research was to investigate the different energy states achievable by each synthesis method. The findings revealed that as the Nb content increased, both the hardness and Young’s modulus of the PM samples decreased (from 4 to 1.5 and 125 to 85 GPa, respectively). For the MA alloys, the hardness and Young’s modulus varied between 3.2 and 3.9 and 100 to 116 GPa, respectively, with the lowest values recorded for 20% Nb (3.2 and 96 GPa). The Young’s modulus of the HiPIMS thin film samples did not follow a specific trend and varied between 110 and 138 GPa. However, an increase in hardness (from 3.6 to 4.8 GPa) coincided with an increase in the β2 phase contribution for films with the same chemical composition (23 at.% of Nb). This study highlights the potential of using HiPIMS gradient films for high throughput analysis for PM and MA techniques. This discovery is important as it provides a way to reduce the development time for complex alloy systems in biomaterials as well as other areas of materials engineering. Graphical abstract
Titanium β-type alloys are preferred biomaterials for hard tissue replacements due to the low Young modulus and limitation of harmful aluminum and vanadium present in the commercially available Ti6Al4V alloy. The aim of this study was to develop a new ternary Ti-Zr-Nb system at 36≤Ti≤70 (at. %). The technical viability of preparing Ti-Zr-Nb alloys by high-energy ball-milling in a SPEX 8000 mill has been studied. These materials were prepared by the combination of mechanical alloying and powder metallurgy approach with cold powder compaction and sintering. Changes in the crystal structure as a function of the milling time were investigated using X-ray diffraction. Our study has shown that mechanical alloying supported by cold pressing and sintering at the temperature below α→β transus (600°C) can be applied to synthesize single-phase, ultrafine-grained, bulk Ti(β)-type Ti30Zr17Nb, Ti23Zr25Nb, Ti30Zr26Nb, Ti22Zr34Nb, and Ti30Zr34Nb alloys. Alloys with lower content of Zr and Nb need higher sintering temperatures to have them fully recrystallized. The properties of developed materials are also engrossing in terms of their biomedical use with Young modulus significantly lower than that of pure titanium.
In the present study, the crystal structure, microstructure, mechanical, corrosion properties, and wettability of bulk Ti23Zr25Nb-x45S5 Bioglass (x = 0, 3, 6, 9 wt.%) and Ti23Zr25Nb—9 wt.% 45S5 Bioglass composites with the addition of 1 wt.% Ag, Cu, or Zn were synthesized and their properties studied. The hardness of these biomaterials is at least two times higher and the elastic modulus lower in comparison to commercial purity (CP) microcrystalline α-Ti. The mechanically alloyed Ti23Zr25Nb—9 wt.% 45S5 Bioglass composite was more corrosion resistant in Ringer’s solution than the bulk Ti23Zr25Nb alloy. Surface wettability measurements revealed the higher surface hydrophilicity of the bulk synthesized composites. The antibacterial activity of Ti23Zr25Nb-based composites containing silver, copper, or zinc against reference strain Streptococcus mutans ATCC 25175 was studied. In vitro bacterial adhesion indicated a significantly reduced number of S. mutans on the bulk Ti23Zr25Nb-BG-Ag (or Cu, Zn) plate surfaces in comparison to the microcrystalline Ti plate surface. Ultrafine-grained Ti23Zr25Nb-BG-Ag (or Cu, Zn) biomaterials can be considered to be the next generation of dental implants.