Ti Nb Research Articles

Training machine learning interatomic potentials for accurate phonon properties

Abstract One of the major challenges in the development of universal machine learning interatomic potentials is accurately reproducing phonon properties. This issue appears to arise from the limitations of available datasets rather than the models themselves. To address this, we develop an extensive dataset of phonon calculations using density-functional perturbation theory. We then show how this dataset can be used to train neural-network force fields, by implementing the training and the prediction of force constants in periodic crystals. This approach improves the quality of phonon properties prediction while reducing the number of structures needed for neural network training. We demonstrate the efficiency of this method using two examples of ternary phase diagrams: Ti—Nb—Ta and Li—B—C. In both cases, neural network predictions for the energy and forces show a considerable improvement, while phonon properties are predicted with high precision for all structures across the entire phase diagrams.

Formation of Structural-Phase State and Elastic and Durometric Properties of Biocompatible Cold-Rolled Titanium Ti–Nb–Zr-Based Alloys during Aging

The methods of scanning electron microscopy, X-ray diffraction analysis, and microindentation are used to study the effect of alloying with zirconium (within 3 to 6 at %) and complex Zr + Sn and Zr + Sn + Ta additions on the evolution of the structure, phase composition, and properties (effective modulus of elasticity, hardness, and wear-resistance parameters) of quenched biocompatible β-titanium (at %) Ti–6% Nb–% Zr, Ti–6% Nb–% Zr, Ti–6% Nb–% Zr, Ti–6% Nb–% Zr–% Sn, and Ti–6% Nb–% Zr–% Sn–0.7Ta alloys during aging (at 400°C for 4, 16, and 64 h) after multipass cold rolling with a total degree of strain of 85%. As compared to the quenching, the cold rolling of the studied Ti–b–r alloys is shown to suppress the occurrence of the β → ω transformation in the course of aging and to favor the acceleration of the decomposition of β solid solution with the formation of nonequilibrium αl phase in the course of aging. The increase in the zirconium content from 3 to 6 at % in the cold-rolled ternary Ti–6% Nb –х% Zr alloys and introduction of complex Zr + Sn and Zr + Sn + Ta additions to the Ti–6% Nb alloy instead of only zirconium addition hinder the decomposition processes of the β phase during aging; this impacts the intensity of variations of the effective modulus of elasticity and microhardness. The aging of the cold-rolled alloys under study was found to allows us to obtain the higher values of the parameters H/Er and (Н is the hardness and Er is the resolved modulus of elasticity) associated with the wear resistance as compared to those for the widely used medical Ti–Al–V alloy. The compositions of the alloys and conditions of their treatment are determined, which allow us to obtain the combination of the highest-level properties.

Bioactive surface modification of Ti–Nb alloy by alkaline treatment in potassium hydroxide solution

Abstract The aim of this work is to compare the responsive behaviour of titanium, niobium and titanium–niobium alloy during alkaline treatment in forming alkaline titanate layer and their resultant bioactive properties. Titanium and niobium powder mixture with composition in the beta region was pressed at 550 MPa and sintered at 1,200 °C for 2 h. The alloy was soaked in potassium hydroxide aqueous solution at 60 °C for 24 h with different concentrations of 0.5 M and 5 M. The effect of post sintering-heat treatment was investigated by annealing the treated alloy at 600 °C for 2 h. X-ray diffraction analysis and Fourier transform infrared spectroscopy analysis were used to evaluate the chemical composition and the functional group of material on the treated alloy surface respectively. Immersion in Hanks solution for 1 day resulted in traces of calcium and phosphate on alloy surfaces treated in different concentrations of alkali as well as post-heat treatment. The cell viability evaluation using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay on the new beta-Ti alloy with potassium-based titanate layer demonstrated potassium hydroxide treatment with a 5 M concentration after post-heat treatment significantly improved cell proliferation, which is a prerequisite for bone mineral apatite deposition.

Improvement of strength in low-carbon Nb–Ti weathering steel through Ce microalloying

In this study, a high-strength low carbon Nb–Ti containing weathering steel was developed. The steel achieved a yield strength of 824.4 MPa and an elongation of 24.4% with the addition of 0.030% Ce as a microalloying element. Precipitation strengthening and dislocation strengthening contributed nearly 60% to the yield strength of the steel. The effects of Ce on the dissolution and precipitation behavior of microalloying elements were analyzed through experimental research and first-principles calculations. Additionally, the associated strengthening mechanisms were elucidated. The findings revealed that the Ce–Nb pairs within the 2 to 7 nearest-neighbor configuration in face-centered cubic Fe exhibited a mutual attraction. This attraction promoted the dissolution of microalloyed carbonitrides, leading to a reduction in the volume fraction of precipitates with diameters above 150 nm from 1.3% to 0.62%. Conversely, in the body-centered cubic Fe structure, Ce–Nb atom pairs were mutually repulsive across all configurations. During the coiling process, the addition of Ce increased the formation of nanoprecipitates in the 0.030% Ce–Nb–Ti weathering steel. Particularly, the volume fraction of precipitates with diameters ranging from 20 to 150 nm in the steel increased from 1.6% to 2.7%, while the fraction of nanoprecipitates also increased from 0.051% to 0.31%. The nanoprecipitates formed within the dislocation substructure of the ferrite significantly enhanced steel strength but reduced its plasticity. Additionally, the addition of Ce led to the formation of numerous fine cementite particles in the localized areas of the steel matrix, which contributed up to 49.2 MPa to the overall strength of the steel.

Enhanced performance of Ti–Nb–N film modified 316L stainless steel and Ti bipolar plates for proton exchange membrane water electrolyser

Proton exchange membrane water electrolyser (PEMWE) is crucial for contemporary hydrogen generation technology. However, the corrosion of bipolar plates (BPPs) poses a significant challenge primarily due to the high anodic potential and acidic environments throughout the operation. This study compares the performance of the innovative Ti–Nb–N film modified 316L stainless steel and Ti bipolar plates under simulated PEMWE operating conditions. Interfacial contact resistance (ICR) experimental results confirm that the Ti–Nb–N film significantly reduces the ICR of the modified Ti plates and 316L stainless steel by approximately 77.7% and 91.0% respectively. According to the polarization tests, the Ecorr of the modified 316L stainless steel and Ti plates shows positive shifts, increasing by 318.49 mV and 376.64 mV, respectively. The Ti–Nb–N film modified 316L stainless steel plates are durable up to 1.4 V (vs. Ag/AgCl), while modified Ti plates maintain performance up to 1.8 V (vs. Ag/AgCl).

Oxidation Behavior of Lightweight Al0.2CrNbTiV High Entropy Alloy Coating Deposited by High-Speed Laser Cladding

High-temperature oxidation resistance is the major influence on the high-temperature service stability of refractory high entropy alloys. The oxidation behavior of lightweight Al0.2CrNbTiV refractory high entropy alloy coatings with different dilution ratios at 650 °C and 800 °C deposited by high-speed laser cladding was analyzed in this paper. The oxidation kinetic was analyzed, the oxidation resistance mechanism of the Al0.2CrNbTiV coating was clarified with the analysis of the formation and evolution of the oxidation layer, and the effect of the dilution rate on high-temperature performances was revealed. The results showed that the oxide layer was mainly composed of rutile oxides (Ti, Cr, Nb)O2 after isothermal oxidation at 650 °C and 800 °C for 50 h. The Al0.2CrNbTiV coating in low dilution exhibited better oxidation performance at 650 °C, due to the dense oxide layer formed with the synergistic growth of fine AlVO3 particles and (Ti, Cr, Nb)O2, and higher percentage of Cr, Nb in (Ti, Cr, Nb)O2 strengthened the lattice distortion effect to inhibit the penetration of oxygen. The oxide layer formed at 800 °C for the Al0.2CrNbTiV coating was relatively loose, but the oxidation performance of the coating in high dilution improved due to the precipitation of Cr2Nb-type Laves phases along grain boundaries, which inhibits the diffusion of oxygen.

Effect of Mn content on the microstructure, mechanical properties and corrosion behavior of Ti–Nb–Zr–Mn alloys processed via spark plasma sintering

Herein, β-type Ti–Nb–Zr–Mn alloys were prepared by ball milling and spark plasma sintering. The effects of Mn addition and quenching treatment on the microstructure, mechanical properties, and corrosion behavior of the alloy were investigated. The Ti–Nb–Zr–Mn alloys are predominantly constituted of equiaxed β Ti grains with a small proportion of ω phase. An increase in Mn content inhibits the precipitation of the ω phase while promoting a more homogeneous solid solution. The tensile strength of the as-prepared alloys decreases and then increases, whereas the plasticity demonstrates the opposite trend. The Elastic modulus and hardness roughly show a trend of decreasing and then increasing. Additionally, the Ti–24Nb–4Zr–2Mn alloy, after undergoing a solid solution treatment at a temperature of 950 °C and subsequent water quenching (referred to as M2-950), demonstrates exceptional comprehensive performance, showing a yield strength of 956 ± 4 MPa, an ultimate strength of 995 ± 13 MPa, an elongation of 16.4 ± 1.6 %, a hardness of 312 ± 11 H V, and an Elastic modulus of 72.6 GPa. Moreover, the corrosion behavior in Ringer's solution was extensively investigated, and the M2-950 alloy has superior corrosion resistance.

Fine grains, dispersed phases and strong crystal defect interactions inducing excellent strength-ductility synergy in powder sintered Cu–18Sn-0.3Ti alloy via hot extrusion and solution treatment

In order to prepare the Cu–18Sn-0.3Ti alloy with excellent mechanical properties to realize the favorable collaborative deformation of Cu–18Sn-0.3Ti alloy and Nb in the preparation process of Nb3Sn superconducting wires by bronze method, the hot extrusion process of the Cu–18Sn-0.3Ti alloy prepared by Direct Current assisted Hot Pressed sintering based on micron atomized spherical alloy powders was systematically investigated by the combination of experiments and finite element simulation in this work. The ultimate tensile strength, yield strength and elongation can reach 683.5 MPa, 414.3 MPa and 33.3 %, respectively, through the optimization of hot extrusion parameters and subsequent solution treatment. The results show that hot extrusion with high strain rate induced the formation of fine α grains and dispersed δ phases. Especially, strong dislocations-annealing twins (ATs) interaction occurred, which was manifested as the pile-up of dislocations at twin boundaries of ATs, slippage of dislocations in multiple directions inside ATs and storage of dislocations inside ATs. Meanwhile, the high strain rate induced the formation of deformation twins inside partial grains. The grain refinement of α matrix, formation of dispersed δ phases and strong interactions of crystal defects were the main reasons for the strength-ductility enhancement of hot extruded samples, and laid an excellent microstructure foundation for further improving the mechanical properties of alloy by subsequent solution treatment. The results not only describe a feasible method for simultaneously enhancing the strength and ductility of Cu–18Sn-0.3Ti alloy, but also provide a theoretical guidance for the strength-ductility enhancement of multicomponent alloys.

On the Mechanisms and Thermocyclic Stability of β → ωiso Transformation in a Superelastic Ti–Nb–Zr Shape Memory Alloy

On the Mechanisms and Thermocyclic Stability of β → ωiso Transformation in a Superelastic Ti–Nb–Zr Shape Memory Alloy

Hydride Destabilization in the Ti–Nb–Cr System Through Nb/Ti Ratio Adjustment

Hydride Destabilization in the Ti–Nb–Cr System Through Nb/Ti Ratio Adjustment

Bulk-phase and surface dual-defective engineering enabled Ti-based nanotubes photoanode for highly efficient photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting employing Ti-based nanostructures represents a promising strategy for achieving solar-to-hydrogen (STH) conversion. Nevertheless, the process is largely hindered by intrinsic sluggish kinetics of the oxygen evolution reaction (OER) process. In this work, we fabricate a high-efficiency Vo/TiNbO photoanode by anodizing the specifically designed Ti–Nb alloys followed by one-step electrochemical reduction. It's worth noting that bulk-phase and surface dual-defective engineering involved in Ti-based nanotubes could be utilized as effective micro-reaction platform for augmented PEC water splitting. Microstructure analysis demonstrates that bulk-phase doping and surface oxygen defects lead to a negative shift of valence-conductive band edges, which increases electrical conductivity and optical absorption. An impressive STH conversion efficiency of the co-doped system could reach 1.12 %, which is 4.6 times of pristine system. Density functional theory (DFT) calculation further confirms that the synergistic dual-defective effects play a vital role in boosting OER process. With the optimization of coordination electron configuration, determining rate step (DRS) energy barrier and adsorption energy of key intermediates decrease. We hope that the rational amalgamation of bulk-phase elements doping with surface oxygen defects introduced in this work may provide insights into developing high-performance nanostructured photoanodes for driving solar water splitting.

Distribution and modes of occurrence of Nb in subbituminous coal: A case study from the Jungar Coalfield, Ordos Basin, China

Niobium has been considered to be enriched in high-Al-Ga in north China coal and coal-hosted Nb(Ta)-Zr(Hf)-REY-Ga polymetallic deposits in the southwestern region of China. However, modes of occurrence and influencing factors of Nb in Al-Ga-rich coal in North China are rarely reported. This study investigated the distribution characteristics of Nb in the No.6 high-Al-Ga coal of the Jungar Coalfield in North China. The in-situ Nb concentration of selected minerals, including kaolinite, Ti-oxides, boehmite, and zircon, is further quantitatively characterized based on multiscale in-situ elemental analyses, including SEM-EDS and LA-ICP-MS spot and mapping analyses. The results showed that Nb is rich in the tonstein and mudstone partings among bulk samples and is highly concentrated in Ti-oxides, followed by zircon among the minerals. A certain amount of Nb is associated with kaolinite and boehmite with different modes of occurrence: vermicular kaolinite (65.94 ppm) > clastic kaolinite (25.43 ppm) > altered K-bearing kaolinite (18.11 ppm) > cryptocrystalline kaolinite (17.03 ppm) > clastic boehmite (9.08 ppm) > cryptocrystalline boehmite (7.97 ppm). The Nb-Nb/Ta and Zr/Hf-Nb/Ta ratios suggest that the primary source of Nb in the No.6 coal is the altered felsic volcanic ash and bauxite deposit. The high-Fe concentration in Ti-bearing minerals indicates that anatase may originate from the alteration of ilmenite with a process of Fe depletion and Nb enrichment. The enrichment of Nb in coal is attributed to the substitution of Nb for Ti in isomorphism in all Ti-oxides, high-Ti, and Ti-bearing minerals.

Multilayered microstructures achieved by a concentration gradient initial condition via spinodal decomposition evidenced in the Ti–Nb multifunctional alloy

Multilayered microstructures achieved by a concentration gradient initial condition via spinodal decomposition evidenced in the Ti–Nb multifunctional alloy

Tribocorrosion behaviour of additively manufactured β-type Ti–Nb alloy for implant applications

β-type Ti–Nb alloys are promising materials for load-bearing implant applications with improved mechanical biofunctionality and biocompatibility. In this work, the electrochemical and tribo-electrochemical behaviour of laser powder bed fusion (LPBF) produced β-type Ti–42Nb alloy processed via Gaussian and top hat laser was investigated and compared with commercial grade β-type Ti–45Nb and α+β-type Ti–6Al–4V ELI. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization experiments were performed in phosphate-buffered saline (PBS) for corrosion behaviour. Tribocorrosion behaviour was studied under open circuit potential (OCP) conditions in PBS by using a reciprocating pin-on-disk tribometer. The passivation nature of the LPBF alloys is more decisive than the microstructural particularities for electrochemical behaviour. The overall corrosion response is similar due to the protective nature of the passive films formed on Ti alloys. Ti–6Al–4V ELI exhibits the best corrosion performance among all tested alloys with lower corrosion and passivation current density values. However, LPBF-produced alloys exhibit less reactive surfaces with better passive film properties compared to Ti–45Nb. In addition, EIS results revealed that passive film resistance values are higher for LPBF-produced alloys than conventionally produced Ti–45Nb. LPBF-produced alloys exhibit better tribo-electrochemical behaviour compared to Ti–45Nb. The differences in volume loss are mainly attributed to the microhardness of the alloys and the volume loss is dominated by mechanical wear. The alloys produced with LPBF show promising corrosion and tribocorrosion performance to be a potential candidate for load-bearing implant applications.

Microstructural evolution, mechanical behavior, and deformation mechanisms of a lightweight Ti–Nb–Cr–V refractory high-entropy alloy at room and elevated temperatures

Refractory high-entropy alloys (RHEAs) have emerged as promising candidates for high-temperature applications owing to their distinctive mechanical properties. However, their limited tensile ductility and high density pose hurdles for further engineering utilization. In this study, we introduce a novel RHEA composition, Ti45Nb30Cr15V10 (at.%), distinguished by its reduced density (∼6.2 g/cm3), achieved through the assistance of CALPHAD (CALculation of PHAse Diagrams) modeling. The as-cast RHEA exhibits a single body-centered cubic (BCC) structure, demonstrating a tensile yield strength of ∼904 MPa along with a total elongation of ∼9.7 %. By employing cold rolling followed by recrystallized annealing (designated as the CRRA sample), we achieve notable enhancements in both strength and ductility. Specifically, the CRRA sample manifests an impressive tensile yield strength of ∼1010 MPa and a total elongation of ∼20.6 % at room temperature. Remarkably, even at an elevated temperature of 700 °C, the CRRA sample maintains notable strength, displaying a yield strength of ∼695 MPa. The observed dislocation behavior, transitioning from dual-system slip to multi-system slip, along with the intricate interactions of dislocation substructures (e.g., loops, tangles, networks, bands, and cells) and kink bands, are identified as the principal deformation mechanisms contributing to the exceptional tensile properties of the CRRA sample at room temperature. At 700 °C, the presence of wavy-slipping dislocations, induced by the strong pinning effect of component fluctuations, predominantly contributes to the strength of the CRRA sample. However, the emergence of Cr2(Ti, Nb, V) Laves phase at grain boundaries results in premature fracture. The extraordinary tensile properties exhibited by the CRRA sample at both room and elevated temperatures underscore its potential for advanced engineering applications.

Enhanced yield stress and reduced elastic modulus of metastable β Ti–Nb alloys deformed by equal channel angular pressing attributed to the Synergistic effect of deformation mechanisms

This work aims to obtain Ti–Nb alloys with a high yield stress, good plasticity, and low elastic modulus. To this end, metastable β Ti–Nb alloys were subjected to multipass equal channel angular pressing (ECAP) deformation at room temperature, and a thorough investigation of their microstructure evolution, deformation mechanisms, and strengthening/toughening mechanisms was conducted through X-ray diffraction, transmission electron microscopy, electron backscatter diffraction, and tensile tests. In the initial deformation stages, multiple deformation mechanisms are observed, including dislocation slip, {332} <113> twinning, stress-induced martensite (SIM) α″-phase, {112} <111> twinning, and stress-induced ω-phase. However, as the strain accumulates, the ω-phase disappears, the volume fraction of the SIM α″-phase gradually decreases, and the dominant deformation mechanism changes to dislocation slip and {332} <113> twinning. The ECAP deformation results in a complex-network microstructure and the precipitation of the nanoscale SIM α″-phase, which leads to the twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) effects. As a consequence, the Ti–Nb alloy simultaneously exhibits a high yield stress and a good plasticity. Furthermore, the high-density dislocations and interfaces generated by the ECAP deformation reduce the stability of the β-phase, and the introduced nanopores cause a decrease in density, resulting in a decrease in the elastic modulus of the alloy.

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.

Microstructure and mechanical behavior of rhombic dodecahedron-structured porous β-Ti composites fabricated via laser powder bed fusion

Porous β-Ti composites hold large promise for lightweight components due to their exceptional strength-ductility synergy. However, their microstructural behavior under both impact and compressive conditions have received limited attention. This study investigates the compressive and impact behavior of porous β-type Ti–25Nb (at.%) composites fabricated using laser powder bed fusion (LPBF). The composites feature a rhombic dodecahedron (RD) lattice structure and incorporate a central solid cylinder with varying diameters. Microstructural characterizations and finite element simulations were employed to analyze mechanical properties and stress distribution. Incorporation of 3 mm radius cylinders (TIII ∼45% porosity) significantly enhances compressive yield stress (88 ± 10 MPa), impact yield stress (153 ± 10 MPa), and impact energy absorption (41.2 J/cm³) while maintaining material plasticity. Compressive and impact loading initiate a martensitic transformation from β to α″ phase, strengthening the alloy through refined α″ formation with a finer grain size than β phase. Notably, a β→ α″ transformation and grain refinement occur in the node region that connects the solid cylinder and lattices, which undergoes significant deformation during impact. This observation suggests the impact resistance of porous β-Ti composites can be enhanced through tailored microstructures and strategic structural design.

Exploring titanium niobium oxides recovered from columbotantalite mineral as lithium-ion batteries electrodes

Titanium niobium oxides (TNO) are chemically recovered from a mineral composed of cassiterite, columbotantalite, rutile and wollastonite. The process involves a series of steps, including pyrometallurgical processes, leaching, and liquid-liquid extraction. It takes advantage of the naturally occurring Ti in the extracted mineral, avoiding the separation of Ti and Nb to directly obtain the valuable Ti–Nb–O compounds. Two compositions can be obtained (Ti2Nb10O29 or TiNb2O7, named TNO-cal and TNO-black, respectively) depending on the thermal treatment after the chemical separation from the original mineral. These compounds have been characterized to describe their composition, morphology and crystallographic properties. The recovered material, without any further purification or functionalization, has been studied as anodes in Lithium-ion batteries (LIBs). Different electrochemical behavior has been observed for voltage ranges of 1–3 V and 0.01–3 V, being the second range which gives best results. In the 1–3V range, TNO-black exhibits a reversible capacity of up to 101.4 mA h g−1 at 1C and maintains 97 % capacity retention after 200 cycles, this is mainly due to Li + insertion/de-insertion processes. Additionally, when expanding the voltage range down to 0.01V, TNO-black displays a specific capacity of approximately 139.1 mA h g−1 after 200 cycles at 1C, whereas TNO-cal reaches a specific capacity of 169 mA h g−1. Extended cycling experiments at a 1C rate for both electrodes reveal that after 200 cycles samples deliver efficiencies relative to the maximum discharge capacity values of 83.4 % (TNO-cal) and 64.4 % (TNO-black), with mean coulombic efficiencies of 97.5 %. These results demonstrate that the recovered materials can effectively function as anodes for LIBs, offering promising application potential, despite the presence of residual silica from the mining process.

On the design of low modulus Ti–Nb–Au alloys for biomedical applications

Developing new low modulus structures is important for reducing the risk of aseptic loosening during loading of implant materials. However, an alloy that may also confer some advantage at preventing septic loosening could dramatically improve the outcomes for patients. Nevertheless, the predictive power of current models remains limited to common alloying additions. As such, this study considers the mechanical properties of a range of Ti–Nb–Au superelastic alloys to elucidate the composition range for which low modulus structures can be achieved. These modulus values are compared to other critical design parameters such as strain recovery and strength. It was found that Au additions are effective at suppressing the formation of the ω phase and allow alloys with lower moduli to be achieved. It was also shown that low β phase stability is critical for achieving the lowest modulus, and that this susceptibility to transform to a martensite may enable higher strengths to be achieved. However, this low β phase stability also limits the strain recovery that may be achieved meaning these two properties are not necessarily independently tuneable. These data provide important context for the design of new systems containing unusual alloying additions such as Au.