Rhenium Alloys Research Articles

Electrochemical Behaviour of Nickel(II)-Rhenium(VII) And Electrodeposition of Nickel-Rhenium Alloy from Choline Chloride - Urea Deep Eutectic Solvent

The electrochemical behaviour of nickel(II)-rhenium(VII) and the electrodeposition of nickel-rhenium alloy using choline chloride: 2 Urea deep eutectic solvent (Reline DES) is reported. Speciation of nickel(II)-rhenium(VII) in Reline DES was studied using UV -Visible spectroscopy. Cyclic voltammetry of Ni2+-ReO4 − in Reline indicates the simultaneous reduction of two metal ions at glassy carbon electrode controlled by non-reversible diffusion process. Chronoamperograms obtained for the reduction of Ni2+-ReO4 − suggests nucleation and three-dimensional growth of bimetallic phase on electrode surface followed progressive nucleation. Electrodeposition of nickel—rhenium alloy was carried out on copper substrates under galvanostatic and potentiostatic conditions. Smooth and uniform deposits were obtained by galvanostatic deposition. X-ray diffraction analysis of the deposit confirmed it to be nickel-rhenium alloy (at −1.2 V) in amorphous form which upon annealing at 1000 °C crystallizes into hexagonal phase with concurrent morphology change from spherical particles to irregular polygons.

Deformation mechanism diagram and deformation instability of a Mo–Re alloy during the hot compression

This study investigates the hot compression behavior of a molybdenum- Rhenium (Mo–Re) alloy, focusing on deformation mechanisms and instability. Utilizing electron backscattered diffraction (EBSD) and transmission electron microscope (TEM), we characterized the microstructure, grain orientation, and deformation behavior across temperatures (650, 750, 850, and 950 °C) and strain rates (0.01, 0.1, 1, and 10s-1). The study reveals that Mo–Re alloys exhibit high hot deformation resistance, necessitating optimal processing conditions for effective plastic deformation. Key findings by EBSD and TEM include the formation of dislocation networks and substructures enhancing grain plasticity. We established a constitutive equation and processing maps, providing valuable insights for industrial applications and future alloy development.

Effect of La2O3 on the properties of molybdenum rhenium alloy

Adding rhenium to molybdenum can improve room temperature processing performance and reduce the ductile brittle transition temperature. Adding lanthanum oxide to molybdenum can refine grain size and improve strength. This work analyzes the effect of adding different amounts of lanthanum oxide to molybdenum rhenium alloys on their properties. The results indicated that with the increase of lanthanum oxide, the tensile strength increased, but the room temperature elongation only increased at 0.6%; as the temperature increases, the trend of tensile strength and elongation at 900 °C and 1100 °C is similar; at 1300 °C, the strength decreases significantly but the elongation increases sharply; the corresponding changes can be explained by the fracture morphology.

Mechanical properties of Mo-Re alloy based on first-principles and machine learning potential function

This study utilizes first principles calculations of density functional theory and Spectral Neighbor Analysis Potential (SNAP) machine learning potential to investigate the influence of rhenium concentration and temperature on the fundamental mechanical properties of Molybdenum-Rhenium alloy. The Mo1−xRex alloys (x = 0.0625–0.5) are constructed using a special quasi-random structure BCC model. The optimized geometries and lattices are used to calculate elastic constants and derivate mechanical parameters, including Bulk modulus, Young's modulus, Shear modulus, etc. The results show that with the increase of rhenium content, the mechanical properties of Mo1−xRex alloy are significantly improved, and higher than pure molybdenum, the best properties are reached at x(Re) = 0.3125. On the other hand, by analyzing the ratio of bulk modulus to shear modulus (B/G) and Poisson's ratio, the alloying of rhenium can also improve the ductility of molybdenum rhenium alloy. To address the challenge of calculating the high-temperature mechanical properties of Molybdenum-Rhenium alloy, a machine learning potential was developed within a training set called Spectral Neighbor Analysis Potential (SNAP). We accurately predicted the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio of Molybdenum-Rhenium alloy over the temperature range of 300–1300 K. Additionally, we provided an accurate description of how temperature affects the mechanical properties and solubility of Molybdenum-Rhenium alloy. This approach aims to overcome the limitations associated with traditional methods and provide accurate predictions of the alloy's mechanical behavior at elevated temperatures.

Rhenium Effect in Thin Films and Wires of Tungsten–Rhenium Alloys

Rhenium Effect in Thin Films and Wires of Tungsten–Rhenium Alloys

A novel performance optimization study in additively manufactured tungsten-5 wt.%Rhenium alloys reinforced with dilute carbon

Due to the inherently limited ductility at room temperature, cracks were almost inevitable in additively manufactured tungsten (W). In this study, we propose a novel W-5 wt.%Re-C ternary alloy with exceptional crack suppression fabricated using laser additive manufacturing. We analyze the advantageous effects of solutes on properties of the W matrix and investigate the influence of planar segregation of carbon (C) on active deformation through density functional theory calculations. In the experiment, carbon-based complexes (CBCs) featuring high-density stacking faults achieved through the planar segregation of C atoms were discovered. Infinite solid solution W2C-Re precipitates were also discovered. The formation of CBCs can alleviate stress concentration to facilitate coordinated deformation. This study investigates the influence of C addition on coordinated deformation behavior in W-based alloys, offering a novel approach for optimizing the performance of additive manufactured components based on W.

Effect of rhenium on corrosion behavior of electrodeposited Co-Cu alloy coating at room temperature and high temperature

Rhenium (Re) is a high-performance refractory metal. Adding rhenium to the alloy can significantly improve the overall performance of the alloy. This paper proposes a simple way to prepare rhenium alloy coatings. The microstructure and XRD results show that the addition of rhenium has a certain effect on the alloy coating. Co-Cu-Re alloy coating had a corrosion current density of 3.2 10−6 (A/cm2) in a solution of 3.5% NaCl, which was 3.4 times lower than that of the mild steel substrate and 2.4 times lower than that of the Co-Cu alloy coating. The charge transfer resistance (Rct) is 4512 (Ω·cm2), which is 6 times larger than that of the mild steel substrate and 1.1 times larger than that of the Co-Cu alloy coating. The electrochemical test results show that the addition of rhenium element can enhance the corrosion resistance of the alloy coating. In the high-temperature oxidation experiment, the oxidation rate constant of the rhenium-containing coating was calculated to be the smallest compared with the mild steel substrate and the Co-Cu alloy coating, and it was observed that the addition of rhenium can effectively inhibit the interdiffusion of elements, indicating that the rhenium-containing coating has stronger high-temperature oxidation resistance. Finally, through the XPS characterization of the alloy coating, the mechanism by which rhenium protects the alloy coating in a high-temperature environment is explained. The addition of rhenium has a broader significance in improving the overall performance of the alloy coating, and will promote its wide application in various fields.

Characterization of ion release from a novel biomaterial, Molybdenum-47.5Rhenium, in physiologic environments

BACKGROUND CONTEXTMetals from spinal implants are released into surrounding tissues by various mechanisms. Metal ion release has been associated with clinical implant failure, osteolysis, and remote site accumulation with adverse events. Significant corrosion and associated metal ion release has been described with currently used spinal implant alloys. A novel metal alloy, Molybdenum-47.5Rhenium alloy (MoRe®), was approved for use in medical implants in 2019 by the FDA. PURPOSETo evaluate the metal ion release profile of MoRe alloy after immersion in both a stable physiologic, as well as in an inflammatory environment. STUDY DESIGNIn vitro study. METHODSThe ion release profile of the MoRe alloy was comprehensively evaluated in-vitro after prolonged immersion in physiologic and inflammatory environments. Ion concentration analyses were then conducted using inductively coupled plasma-mass spectrometry (ICP-MS) methods. Comparative testing of titanium (Ti-6Al-4V) and cobalt chromium (Co-28Cr-6Mo) was also performed. RESULTSUnder baseline physiologic conditions, the MoRe alloy demonstrates very low molybdenum and rhenium ion release rates throughout the 30-day test period. During the first time interval (day 0–1), low levels of molybdenum and rhenium ions are detected (<0.3 μg/cm2 day) followed by a rapid reduction in the ion release rates to <0.05 μg/cm2 day during the second time interval (days 1–3) followed by a further reduction to very low steady-state rates <0.01 μg/cm2 day during the third time interval (days 3–7), which were maintained through 30 days. In the inflammatory condition (H2O2 solution), there was a transient increase in the release of molybdenum and rhenium ions, followed by a return to baseline ion release rates (days 2–4), with a further reduction to low steady-state rates of ∼0.01 μg/cm2 day (days 4–8). The measured molybdenum and rhenium ion release rates in both steady state (<0.01 μg/cm2 day), and inflammatory environments (0.01 μg/cm2 day) were far below the established FDA-permitted daily exposure (PDE) of 1,900 μg/cm2 day for molybdenum and 4,400 μg/cm2 day for rhenium. In contrast, titanium and cobalt chromium approached or exceeded their established PDE values in an inflammatory environment. CONCLUSIONSThe novel biomaterial MoRe demonstrated a lower metal ion release profile in both a physiologic and inflammatory environment and was well below the established PDE. Comparative testing of the cobalt-chromium and titanium alloys found higher levels of ion release in the inflammatory environment that exceeded the PDE for cobalt and vanadium.

Electrodeposition, composition and properties of cobalt–rhenium alloys coatings

This paper compares the chemical composition, current efficiency, crystal structure, as well as the magnetic, electrocatalytic, and corrosion properties of CoRe electrolytic alloys.

Molybdenum as a Potential Biocompatible and Resorbable Material for Osteosynthesis in Craniomaxillofacial Surgery-An In Vitro Study.

Titanium and stainless steel are commonly known as osteosynthesis materials with high strength and good biocompatibility. However, they have the big disadvantage that a second operation for hardware removal is necessary. Although resorbable systems made of polymers or magnesium are increasingly used, they show some severe adverse foreign body reactions or unsatisfying degradation behavior. Therefore, we started to investigate molybdenum as a potential new biodegradable material for osteosynthesis in craniomaxillofacial surgery. To characterize molybdenum as a biocompatible material, we performed in vitro assays in accordance with ISO Norm 10993-5. In four different experimental setups, we showed that pure molybdenum and molybdenum rhenium alloys do not lead to cytotoxicity in human and mouse fibroblasts. We also examined the degradation behavior of molybdenum by carrying out long-term immersion tests (up to 6 months) with molybdenum sheet metal. We showed that molybdenum has sufficient mechanical stability over at least 6 months for implants on the one hand and is subject to very uniform degradation on the other. The results of our experiments are very promising for the development of new resorbable osteosynthesis materials for craniomaxillofacial surgery based on molybdenum.

Structural and modal analysis of gas turbine blade using ansys

Gas turbine technology has advanced significantly during the last twenty years. The advancement in materials technology, new coatings, and novel cooling techniques are driving the expansion. Material selection is critical since turbomachinery design is complicated, and material performance is directly connected to efficiency. The materials should be able to withstand high vibrations, high temperature, and pressure. In this work, the maximum stress and the deformation induced due to pressure were determined to study the vibrational response, mode shapes, and natural frequencies. Four different materials have been considered, namely Inconel 617, Titanium alloy, Rhenium alloy, and Nimonic 80A. A suitable material for a gas turbine blade was suggested after analyzing these materials. The 3D CAD model is modeled in CATIA V5 and analysis is carried out using FEM-based software ANSYS

The potential––pH diagram for rhenium

The aqueous chemistry of rhenium is of importance for the hydrometallurgical processes involving rhenium alloys, for the leaching of rhenium from its ores and alloys, and for the electrochemical deposition of thin rhenium films. This study aims to present the chemical and electrochemical equilibria in the Re – H2O system in the form of the Pourbaix diagram. The existing variants of the Pourbaix diagrams for rhenium available in the literature were reviewed; it was shown that they significantly differ from each other in the composition and the values of the thermodynamic activities of rhenium species. The thermodynamic properties of aqueous rhenium species, including the standard Gibbs energies of formation and the standard electrode potentials of half-cell reactions involving it, were collected and analysed. The compounds of rhenium (+7) and rhenium (+6) not isolated in the free aqueous state, and rhenium hydride compounds were discussed. The self-consisted set of thermodynamic data for further calculations was obtained. Using these data, the basic chemical and electrochemical equilibria involving aqueous rhenium species at the temperature of 298 K and the air pressure of 1 bar were calculated. For the first time the potential – pH diagram for the Re – H2O system at the temperature of 298 K, the air pressure of 1 bar and the different activities of rhenium species in the solution were constructed. The influence of thermodynamic activities of aqueous rhenium compounds on the stability of rhenium oxides was discussed. It was shown that rhenium trioxide ReO3 is thermodynamically stable only in concentrated solutions (at the activities of rhenium species not less than 10–6 М), rhenium dioxide ReO2 loses the stability at the activities of rhenium species less than 10–8 М, and rhenium sesquioxide Re2O3 does so at the activities of rhenium species not less than 10–14 М. The necessity of the measurement of the stability constants of ortho- and mesorhenate anions, as well as nonahydridorhenates for a deeper understanding of the aqueous rhenium chemistry was discussed.

Weldability of Molybdenum–Rhenium Alloy Based on a Single-Mode Fiber Laser

Due to its high thermal conductivity and favorable machinability, molybdenum–rhenium (Mo–Re) alloys have huge prospects in the field of high-temperature heat pipes. However, the weldability of Mo–Re alloys has not yet been systematically investigated. Based on an orthogonal test, the influence law of the single-mode fiber laser welding parameters on the weld profile and the mechanical properties of the joints was studied. Furthermore, the existence mode and the distribution law of Re in the fusion zone (FZ) were explored using X-ray photoelectron spectrometer (XPS) and the electron backscattered diffraction (EBSD) system. The results showed that weld penetration and width are most significantly influenced by power, and that these increased with increasing power. The tensile strength of the Mo–Re alloy joints reached 250 MPa, and no obvious hardening was found in the FZ. Re in the FZ also appeared as ReO2, ReO3, and ReC, apart from the atomic state.

Study on high-temperature mechanical properties of W25Re alloy

Tungsten rhenium alloy is widely used in aerospace, weapon electronics, and other high-temperature fields. W25Re alloy bars were prepared by powder metallurgy combined with the rolling deformation process. The mechanical properties of W25Re alloy were studied. The results show that rolled W25Re alloy bars have excellent mechanical properties. The tensile strength at room temperature is up to 1650 MPa and the elongation is 15%. As temperature increases, the tensile strength of W25Re alloy decreases rapidly, and the elongation first increases and then decreases. However, at 2000 °C, the tensile strength of more than 200 MPa and elongation of 16% can still be maintained. The fracture morphology shows that the dimples disappear and dynamic recrystallization occurs at 1600 °C and that the grain grows further at 2000 °C. The analysis shows that with increasing temperature, the increasing grain size and decreasing grain adhesion lead to decreasing strength and plasticity at 2000 °C.

A Porous Tungsten Substrate for Catalytic Reduction of Hydrogen by Dealloying of a Tungsten–Rhenium Alloy in an Aqueous Solution of Hydrochloric Acid

Selective dissolution of a tungsten (85 wt.%)–rhenium (15 wt.%) alloy with rhenium in hydrochloric acid at the temperature of 298 K and anodic polarization modes was carried out to develop a porous catalytic substrate and to recycle rare metals. The parameters of the effective selective anodic dissolution of the tungsten–rhenium alloy, including the differences in applied potentials and electrolyte composition, were found. It was established that samples of the tungsten–rhenium alloy possess the smallest average pore size after being exposed for 6000 s. The obtained porous tungsten samples were characterized by X-ray diffraction and scanning electron spectroscopy. A thermodynamic description of the processes occurring during the anodic selective dissolution of a binary alloy was proposed. In the course of the work, the selectivity coefficient was determined using an X-ray fluorescence wave-dispersion spectrometer XRF-1800. The existence of a bimodal structure on the tungsten surface after dealloying was proved.

Electrolytic production and characterization of nickel–rhenium alloy coatings

Abstract Electrolytic Ni–Re alloy coatings were obtained in galvanostatic conditions from nickel–rhenium baths with different contents of ammonium rhenate(vii) (0.5, 1.25, 2.5 and 5 g·L−1). The surface morphology, chemical, and phase composition of the obtained materials were determined. The coatings’ corrosion resistance tests were carried out in a 5% NaCl solution. Based on the tests, it was found that the highest corrosion resistance characterizes the coating with the highest rhenium content (37%). This material can be recommended for practical use as a protective coating. The density of the deposited Ni–37Re alloy was determined, and its specific surface area was assessed. The melting point, hardness, and electrical conductivity were also determined.

Electrodeposition of Rhenium-Iron Alloy from Water-in-Salt Electrolytes

Rhenium is a refractory metal and has distinguished properties, including excellent wear resistance, superior tensile strength, high creep-rupture, and resistivity in elevated temperatures [1]. More interestingly, it is also a superconductor at cryogenic temperatures. Electrodeposited superconducting materials can be used to fabricate superconducting circuits for cryogenic quantum devices [2,3]. As rhenium oxide is often inevitably formed during rhenium deposition, which prevents further reduction of itself into rhenium metal, highly acidic electrolytes are typically required for rhenium electrodeposition [4]. A significant amount of proton in the electrolyte, however, exacerbates hydrogen evolution reaction, resulting in not only a low current efficiency but also hydrogen incorporation into the metal deposit. The latter often, causes cracks and pin holes in the deposited films. Water-in-salt electrolyte is an aqueous solution with super high concentration of salt, e.g. LiCl, where the hydration of salt depletes or significantly decreases free water molecules, thus disrupting the hydrogen bond network, and suppressing proton reduction. In our previous work, a water-in-salt electrolyte of super high concentration of LiCl was applied to electrodeposit rhenium and rhenium-cobalt alloy to mitigate hydrogen evolution reaction and film cracks [5,6].In this presentation, the study has been extended to rhenium-iron alloy. While the rate decrease of hydrogen evolution reaction upon the use of water-in-salt electrolyte was expected, a surprisingly strong enhancement of Re deposition rate in the presence of Fe was also observed. Figure 1 shows the partial current densities of rhenium during alloy deposition, where it not only showed more than 10x deposition rate compared with an elemental Re water-in-salt electrolyte.The morphology and crystallographic structure of ReFe films and the effect of annealing will be characterized with microscopic and diffraction techniques and will be discussed in conjunction with pure metal films. Superconductivity and the effect of alloying on the critical temperature will also be discussed in detail in the talk. Figure 1 . The rhenium partial current in the deposited films from different applied potential from four electrolytes with 0, 10, 20, and 35 mM iron.

Corrosion Behavior of Nickel–Rhenium Alloys in Concentrated Acids

Corrosion Behavior of Nickel–Rhenium Alloys in Concentrated Acids

TaC Precipitation Kinetics During Cooling of Co−Re‐Based Alloys

Cobalt−rhenium (Co−Re) alloys are developed for high‐temperature applications at ≈1200 °C and are strengthened by dispersion of nanosized tantalum carbide (TaC) precipitates. Herein, the precipitation behavior during cooling from supersolution depending on the cooling rate and the addition of chromium is presented. The phase composition (matrix phases and TaC) is analyzed from the wide‐angle neutron diffraction patterns measured in situ during temperature cycling. The precipitation of nanosized TaC particles is measured by in situ and ex situ neutron and X‐ray small‐angle scattering. The in situ measurements are used to extract the temperature‐dependent volume fraction of the precipitates; the final size distribution after cooling is extracted from the ex situ measurements. A Kampmann−Wagner's numerical (KWN) model is adapted to isochronal cooling processes. The in situ measurements give the unique possibility to calibrate the model parameters, whereas the ex situ measurements are used to assess the model predictions.

Microstructural Changes in Ni-Al-Cr-Based Heat-Resistant Alloy with Re Addition

This paper presents scanning and transmission electron microscope investigations of the structure, phase composition, and morphology of a heat-resistant alloy modified by thermal treatment and additionally alloyed by rhenium. The rhenium alloy was obtained by using the directional crystallization technique. The structural investigations were carried out for two states of the alloy, i.e., (1) original (after the directional crystallization); (2) after the directional crystallization with 1150 °C annealing for 1 h and 1100 °C annealing for 480 h. It is shown that fcc-based γ- and γ′-phases are primary in all states of the alloy. The γ′-phase has an L12 structure, while γ-phase is a disordered phase. It was found that after directed crystallization, the volume fraction of the γ′ phase is ~85%, the fraction of the γ-phase is less than 10%. Annealing leads to an increase in the γ′- phase up to 90%, the proportion of the γ-phase practically does not change. Rhenium is a phase-formation element. The investigations show that high-temperature annealing modifies the structural and phase conditions of the heat-resistant alloy.