Ta Zr Alloy Research Articles

Additive manufacturing of a low modulus biomedical Ti–Nb–Ta–Zr alloy by directed energy deposition

While β titanium alloys have garnered extensive attention as a new generation of biomedical materials designed to mitigate stress shielding due to their low modulus, the realm of additive manufacturing for these alloys is still in its nascent stages. This study focuses on the additive manufacturing of Ti–35Nb–5Ta–7Zr alloy powder via directed energy deposition (DED). The primary objectives were assessing the feasibility of employing DED for this alloy powder and identifying processing parameters to achieve nearly dense components. Systematic exploration of the effect of various processing parameters was performed, and the resultant impact on the densification of the produced specimens was studied. Comprehensive analysis of the microstructure, mechanical properties, electrochemical behavior, and cell studies of fully dense sample coupons were performed. These fully dense samples were found to exclusively comprise the β phase of titanium, resulting in a reduced modulus of elasticity (approximately 44–47 GPa) resulting in high yield strength to elastic modulus ratio. Microstructural examinations revealed the presence of both columnar and equiaxed dendrites, with grains transitioning from columnar to equiaxed (known as CET). Electrochemical testing of the coupons indicated exceptional corrosion resistance in the additively manufactured TNZT alloy. Pre-osteoblasts cultured on the alloys showed good attachment, viability, and growth to confirm cytocompatibility. These findings unveiled the attainment of high strength, favorable ductility, a low elastic modulus, excellent corrosion resistance, and cytocompatibility in dense samples created via DED of Ti–35Nb–5Ta–7Zr. These outcomes hold immense significance for the production of patient-specific medical implants manufactured from β-Ti alloys.

Effects of Zr addition on the microstructures, mechanical properties and thermal stability of Cu-Ta alloys

In this work, Cu-1.4 wt%Ta-Zr alloys with different Zr content (0, 0.1, 0.2 and 0.5 wt%) were fabricated by mechanical alloying combined with spark plasm sintering. The effect of Zr addition on the microstructures, mechanical properties and thermal stability of Cu-Ta alloy were characterized. Cu-Ta alloys composes of ultrafine equiaxed grains along with the uniformly dispersion of semi-coherent Ta nanoclusters and incoherent Ta coarse particles. As Zr is introduced into Cu-Ta alloy, the Ta precipitates were effectively refined, especially for the reduction of Ta coarse particles. The significant refinement effect of the grains is realized when Zr content reaches 0.2 wt%, and high-proportioned nano-sized grains are facilitated to form, along with the activation of a lot of twins and the formation of intermetallic composed of Cu and Zr. The dislocation density and strength increase remarkably with the increase of Zr content, and the highest strength (499 MPa for yield strength and 600 MPa for ultimate tensile strength) is achieved as the Zr content is up to 0.2 wt%. Compared with Cu-Ta alloy (382 MPa for yield strength and 560 MPa for ultimate tensile strength), the significant increment of 31% for the yield strength is successfully realized by Cu-Ta-0.2 wt%Zr alloy. Cu-Ta-0.2 wt%Zr alloys exhibit the excellent thermal stability, and the hardness keeps stable even the sample was annealed at 700 °C for 300 h, showing superior microstructural stability in comparison with Cu-Ta alloy (∼4.5% reduction of the hardness after 300 h at 700 °C). The softening temperature of Cu-Ta-0.2 wt%Zr alloy is up to 1028 °C (1022 °C for Cu-Ta alloy) along with higher hardness than that of Cu-Ta alloy at the same annealing temperature. This study provides a new way to fabricate dispersion strengthened Cu alloys with high strength, exceptional thermal stability and softening resistance, which have great potential application value in the field of future fusion reactor.

Superconductivity of Ta-Hf and Ta-Zr alloys: Potential alloys for use in superconducting devices

The electronic properties relevant to superconductivity are reported for bulk Ta-Hf and Ta-Zr body centered cubic alloys, in a large part to determine whether their properties are suitable for potential use in superconducting qbits. The body centered cubic unit cell sizes increase with increasing alloying. The results of magnetic susceptibility, electrical resistivity, and heat capacity characterization are reported. While elemental Ta is a type I superconductor, the alloys are type II strong coupling superconductors. Although decreasing the electron count per atom is expected to increase the density of electronic states at the Fermi level and thus the superconducting transition temperature (${T}_{c}$) in these systems, we find that this is not sufficient to explain the significant increases in the superconducting ${T}_{c}$'s observed.

Influence of liner structure on EFP formation and penetration performance of a Ta-Zr liner

In order to study the formation and penetration performance of reactive liner, in this paper, a Ta-Zr alloy is used as the liner material, and large cone angle liner, spherical liner and arc-cone liner are simulated and analyzed by using AUTODYN software. The following conclusions are obtained: (1) The EFP formed by large cone angle liner has good flight stability, followed by arc cone liner; (2) The length diameter ratio of spherical shaped charge liner is larger than that of arc cone shaped charge liner; (3) The EFP penetration depth of the arc cone shaped liner is larger, and the EFP incident aperture of the large cone angle shaped liner is larger.

Increasing the Thermal Stability and High-Temperature Strength of Vanadium Alloys by Strengthening with Nanosized Non-Metallic Particles

Using the methods of scanning and transmission electron microscopy, the features of the structural-phase state of a vanadium alloy of the V-Cr-Ta-Zr system after a combined treatment, which consisted in cyclic alternation of thermomechanical and chemical-heat treatments, were studied. The values of yield strength and ductility of the V-Cr-Ta-Zr alloy were determined, depending on the stabilization and test temperatures. It was established that, after the combined treatment, the structural-phase state of the V-Cr-Ta-Zr alloy was composite, in which the joint implementation of dispersion and substructural strengthening ensured the formation of a gradient grain structure with a polygonal state, the elements of which were fixed by nanosized ZrO2 particles characterized by a high thermal stability. Such modification of the microstructure was accompanied by an increase in the high-temperature strength and a shift in the upper limit of the temperature stability interval towards high temperatures, of up to 900 °C. It was assumed that the polygonal state inside the grains contributed to the implementation of cooperative mechanisms of the dislocation-disclination type, which ensured the accommodation of the material in the "high-strength state" under loading.

The effect of Ti and Zr content on the structure, mechanics and energy-release characteristics of Ti–Zr–Ta alloys

Energetic structural materials (ESMs) are a new type of structural materials with bearing and damage characteristics. In this work the microstructure, mechanical properties and energy release characteristics of multi-element Ti–Zr–Ta alloys with good casting performance were studied. The microstructure of the TixZrTa alloys gradually change from BCC + HCP to single BCC structure with the increase of Ti. While the Ti2ZryTa alloys was still uniform and single BCC structure with the increase of Zr. The evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti–Zr–Ta alloys. The synergistic effect of dual phase structure increases the fracture strain of TixZrTa (x = 0.2, 0.5) with the Ti content decreases, while the fracture strain of TixZrTa (x = 2.0, 3.0, 4.0) gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation movement. And as Zr content increases, the fracture strain of Ti2ZryTa alloys decrease, then the oxidation reaction rate and fragmentation degree gradually increase. The higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of TixZrTa alloys with low Ti content and Ti2ZryTa alloys with high Zr content.

Effect of Alloying Elements on the Compressive Mechanical Properties of Biomedical Titanium Alloys: A Systematic Review.

Due to problems such as the stress-shielding effect, strength–ductility trade-off dilemma, and use of rare-earth, expensive elements with high melting points in Ti alloys, the need for the design of new Ti alloys for biomedical applications has emerged. This article reports the effect of various alloying elements on the compressive mechanical performance of Ti alloys for biomedical applications for the first time as a systematic review following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines on this subject. The search strategy in this systematic review used Scopus, Web of Science, and PubMed databases and searched the articles using (Beta-type OR β) AND Titanium AND (Mechanical property OR Microstructure) AND Alloying element keywords. Original articles from 2016 to 2022 published in English have been selected for this study as per the inclusion criteria. The results have shown that Nb can be used as the primary alloying element with Ti as it is a strong β-stabilizer element which also reduces the elastic modulus of Ti alloys. The β-eutectic elements (Fe, Cr, and Mn) have also emerged as cost-effective alloying elements that could improve the mechanical performance of Ti alloys. Ti–Nb–Zr–Ta alloyed with Si has shown potential to withstand the strength–ductility trade-off dilemma. The combination of a Ti–Nb binary alloy has emerged as an attractive material for designing low elastic modulus Ti alloys. The mechanical performance of the Ti–Nb alloy can be further improved using the β-eutectic (Fe, Cr, and Mn) and neutral (Zr, Sn) elements to be alloyed with a Ti–Nb binary alloy. The strength–ductility trade-off issue can be overcome using Si as an alloying element in Ti–Nb–Zr–Ta alloys.

Microstructure and Mechanical Properties of V–Cr–Ta–Zr Alloy after Combined Treatment

Microstructure and Mechanical Properties of V–Cr–Ta–Zr Alloy after Combined Treatment

Effect of Ti on the Structure and Mechanical Properties of TixZr2.5-xTa Alloys.

To determine the effects of Ti and mixing entropy (ΔSmix) on the structure and mechanical proper-ties of Zr-Ta alloys and then find a new potential energetic structural material with good me-chanical properties and more reactive elements, TixZr2.5−xTa (x = 0, 0.5, 1.0, 1.5, 2.0) alloys were investigated. The XRD experimental results showed that the phase transformation of TixZr2.5−xTa nonequal-ratio ternary alloys depended not on the value of ΔSmix, but on the amount of Ti atoms. With the addition of Ti, the content of the HCP phase decreased gradually. SEM analyses revealed that dendrite morphology and component segregation increasingly developed and then weakened gradually. When x increases to 2.0, TixZr2.5−xTa with the best mechanical properties can be ob-tained. The yield strength, compressive strength and fracture strain of Ti2.0Zr0.5Ta reached 883 MPa, 1568 MPa and 34.58%, respectively. The dependence of the phase transformation and me-chanical properties confirms that improving the properties of Zr-Ta alloys by doping Ti is feasible.

Exfoliation Resistance, Microstructure, and Oxide Formation Mechanisms of the White Oxide Layer on CP Ti and Ti-Nb-Ta-Zr Alloys.

We found that specific biomedical Ti and its alloys, such as CP Ti, Ti–29Nb–13Ta–4.6Zr, and Ti–36Nb–2Ta–3Zr–0.3O, form a bright white oxide layer after a particular oxidation heat treatment. In this paper, the interfacial microstructure of the oxide layer on Ti–29Nb–13Ta–4.6Zr and the exfoliation resistance of commercially pure (CP) Ti, Ti–29Nb–13Ta–4.6Zr, and Ti–36Nb–2Ta–3Zr–0.3O were investigated. The alloys investigated were oxidized at 1273 or 1323 K for 0.3–3.6 ks in an air furnace. The exfoliation stress of the oxide layer was high in Ti–29Nb–13Ta–4.6Zr and Ti–36Nb–2Ta–3Zr–0.3O, and the maximum exfoliation stress was as high as 70 MPa, which is almost the same as the stress exhibited by epoxy adhesives, whereas the exfoliation stress of the oxide layer on CP Ti was less than 7 MPa, regardless of duration time. The nanoindentation hardness and frictional coefficients of the oxide layer on Ti–29Nb–13Ta–4.6Zr suggested that the oxide layer was hard and robust enough for artificial tooth coating. The cross-sectional transmission electron microscopic observations of the microstructure of oxidized Ti–29Nb–13Ta–4.6Zr revealed that a continuous oxide layer formed on the surface of the alloys. The Au marker method revealed that both in- and out-diffusion occur during oxidation in Ti–29Nb–13Ta–4.6Zr and Ti–36Nb–2Ta–3Zr–0.3O, whereas only out-diffusion governs oxidation in CP Ti. The obtained results indicate that the high exfoliation resistance of the oxide layer on Ti–29Nb–13Ta–4.6Zr and Ti-36Nb-2Ta-3Zr-0.3O are attributed to their dense microstructures composing of fine particles, and a composition-graded interfacial microstructure. On the basis of the results of our microstructural observations, the oxide formation mechanism of the Ti–Nb–Ta–Zr alloy is discussed.

Influence of Chemical-Heat Treatment on Thermal Stability of Microstructure, Mechanical Properties and Fracture of V–Cr–Ta–Zr Alloy

Influence of Chemical-Heat Treatment on Thermal Stability of Microstructure, Mechanical Properties and Fracture of V–Cr–Ta–Zr Alloy

Structure and Properties of Ta–Zr Alloys Produced by High-Speed Quenching from a Liquid State

Structure and Properties of Ta–Zr Alloys Produced by High-Speed Quenching from a Liquid State

Structure and properties of Ta-Zr alloy obtained by high-speed melt quenching from liquid state

The paper considers the effect of Ta-Zr binary system splat quenching implemented by the method of pendant drop melt extraction. The study was conducted using two mixtures of tantalum and zirconium elementary powders with a content of 60 and 6 % of tantalum respectively. After mixing, the compositions were pressed at 250 MPa in a steel mold on a hydraulic press. Sintering was carried out in a vacuum furnace at 1350 °C and a pressure of 10-3 Pa. Splat quenching was carried out in a vacuum at 2•10-2 Pa using electron-beam heating and a spinning disk absorber. Resulting fiber thickness was 15 to 80 gm. The results of testing splat-quenched Ta—Zr alloy discrete fibers and samples formed as a result of rod stock melting by electron-beam heating (as-cast) were studied and compared. It was found that the structure of splat-quenched fibers of the alloy with a Ta content of 6 wt.% consists of 5—10 gm needle-shaped grains, and the alloy with a Ta content of 60 wt.% has a columnar dendritic structure. A study of tantalum and zirconium distribution across the fiber cross-section showed that cooling rate reduction to less than 105 K/s leads to monotectoid transformation in the alloy with a tantalum content of 60 wt.%. It was found that for an alloy with 6 wt.% Ta the fiber microhardness value is 1.5 times higher in comparison with the same alloy without quenching, and for an alloy with Ta 60 wt.% it is higher by a factor of two.

Very high upper critical fields and enhanced critical current densities in Nb3Sn superconductors based on Nb–Ta–Zr alloys and internal oxidation

The inhibition of Nb3Sn grain growth in the presence of ZrO2 nanoparticles appears to be one of the most promising method for pushing the critical current densities of Nb3Sn superconducting wires to levels that meet the requirements set for the Future Circular Collider. We have investigated the effect of ZrO2 nanoparticles formed by the internal oxidation of Zr on the superconducting properties and microstructure of Nb3Sn formed from Nb-1 wt%Zr, Nb-7.5 wt%Ta, Nb-7.5 wt%Ta-1 wt%Zr and Nb-7.5 wt%Ta-2 wt%Zr alloys. A monofilamentary wire configuration was used, with a 0.22 mm outer diameter Nb-alloy tube containing a core of powdered metal oxide (SnO2, CuO or MoO3) as oxygen source and successive deposits of Cu, Sn and Cu on the outer surface. As determined from inductive measurements, the layer critical current densities of the samples based on Nb alloys with internally oxidized Zr were superior to those based on Nb-7.5 wt%Ta. The samples based on Nb-7.5 wt%Ta-1 wt%Zr and Nb-7.5 wt%Ta-2 wt%Zr showed higher critical current densities at high magnetic fields (above 10–15 T), and upper critical fields exceeding 28.5 T at 4.2 K (99% normal state resistivity criterion). A record value of 29.2 T of the upper critical field at 4.2 K was obtained on samples based on Nb-7.5 wt%Ta-2 wt%Zr. Hypotheses are proposed and discussed for explaining this unexpected increase of the upper critical field, by considering the possible effects of non-oxidized Zr on the superconducting properties of Nb3Sn and of the oxidized Zr on the formation and microchemistry of Nb3Sn. Regardless of sample type the Nb3Sn grains observed in our samples have an aspect ratio of 1.5–1.7. When compared in the short axis direction, the mean distance between grain boundary intercepts (lineal intercept method) is ∼40% smaller in the samples with internally oxidized Zr than in the reference samples based on Nb-7.5 wt%Ta. In the long axis direction the reduction is of 20%–30%.

Special Aspects of the Surface Scale Growth during Oxidation of V–Cr–Ta–Zr Alloy in Air

The results of a study of features of the surface scale growth on the V–Cr–Ta–Zr vanadium alloy specimens during short-term oxidation in air are presented. It is shown that in the initial oxidation stages, irrespective of the specimen microstructure, the surface scale growth rate can be an order of magnitude higher than that in the course of long-term treatment. It is found out that the scale is characterized by open porosity formed as a result of sticking of the V2O5 plate-like flakes together. It is suggested that a decrease in the oxidation rate is a consequence of an increase in the surface scale thickness, resulting in a slower supply of oxygen to the specimen surface on which the processes of scale nucleation and growth, as well as diffusion saturation of the subsurface vanadium-alloy layer with oxygen are observed.

Additive manufacturing of tantalum-zirconium alloy coating for corrosion and wear application by laser directed energy deposition on Ti6Al4V

In this work, a preplaced TaZr alloy powder layer (Ta:Zr = 7:3 in wt%) is coated on a Ti6Al4V substrate by laser-based directed energy deposition. Crack-free, smooth TaZr alloy coating is acquired, and the content of elements (Ta, Zr, Ti, Al, V) distributes in a gradient. In this coating, the bcc α-Ta grains with a rectangular shape and a size of 10–20 nm surrounded by the TiZr phase, the Al3Zr4 phase mainly gathers in grain boundary. The corrosion resistance of the coating and substrate is tested via electrochemical measurement and the coating exhibits a better resistance in 0.5 mol/L H2SO4 solution. The average microhardness of the coating is around 600 HV, which is ~1.7 times than that of the substrate. The wear test results show the mass loss of the coating is approximately 60 times lower than the substrate at room temperature. It is believed that this coating could shed light on not only the protection of Ti-based alloy, but also the Fe-based and Ni-based components with the functionally graded transition layers.

Microstructure and compressive properties of porous Ti–Nb–Ta–Zr alloy for orthopedic applications

Abstract

Influence of oxidation duration on features of surface scale of V–Cr–Ta–Zr alloy

Investigation results of surface oxide scale features during the oxidation of V–Cr– Ta–Zr alloy in air are presented. Intensive oxidation processes in time interval under study lead to an increase in the scale thickness. Oxide scale structure is characterized by open porosity formed as a result of sticking together of small flakes of plate-shaped oxides (V2O5).

Influence of annealing temperature on microstructure and microhardness of V–Cr–Ta–Zr alloy

The effect of stabilizing annealing temperature on the features of microstructure and microhardness of V–Cr–Ta–Zr alloy after thermomechanical treatment by regime II was studied. Main stages of relaxation processes are revealed. Characteristic microstructure parameters and microhardness values are determined for each relaxation stage.

Preparation of Ti–Nb–Ta–Zr alloys for load-bearing biomedical applications

Ti–Nb–Ta–Zr alloys for biomedical applications were successfully fabricated by arc melting (AM) and diffusion bonding. The microstructure, mechanical properties and electrochemistry behavior in a simulated body fluid (SBF) were studied. It shows that melted Ti–Nb–Ta–Zr alloy mainly contains β phase although there are a few Ti-rich phases and micropores, the number of which is lower than that in sintered sample with a few Ti-rich and Ta-rich phases. The melted alloys present higher strength (1224 MPa), Young’s modulus (15.3 GPa) and corrosion potential (− 0.34 V) in SBF, while total recovery strain ratio (67.5%) and pseudoelastic strain ratio (8.4%) of sintered Ti–Nb–Ta–Zr alloy keep higher value than 35.7% and 5.0% for melted Ti–Nb–Ta–Zr. The reasons were discussed based on the microstructure of the Ti–Nb–Ta–Zr alloys.