Fe-Cu Alloys Research Articles

Influence of the applied external magnetic field on surface area and catalytic activity of electrodeposited Cu-Fe alloys

Influence of the applied external magnetic field on surface area and catalytic activity of electrodeposited Cu-Fe alloys

Fluorine-doped perovskite cathodes with boosted electrocatalytic activity for CO2 electrolysis

Global energy demands that have traditionally been satisfied by the use of fossil fuels have led to substantial emissions of CO2, an important greenhouse gas. Solid oxide electrolysis cells (SOECs) offer a practical approach for transforming CO2 into valuable fuels. Accordingly, creating stable electrocatalysts and perovskite cathodes capable of efficiently converting CO2 is a primary aim for the further development of SOECs. Although reconstructing active sites during CO2 electrolysis is significantly challenging, it is also constrained by our lack of understanding of this process. Herein, we introduce an innovative strategy that involves co-doping with Cu and F to better facilitate the exsolution reaction, which resulted in the formation of an advanced cathode composed of Cu-Fe alloy nanoparticles embedded in a fluorine-doped Sr2Fe1.5Mo0.5O6−δ (SFM) ceramic matrix. The in-situ electrochemical reconstruction of the SFM cathode through co-doping not only improves mass-transfer efficiency during CO2 electrolysis but also enhances the catalytic activity and durability of the ceramic cathode. A SOEC assembled with this material as a symmetrical electrode delivered 4.99 mL min−1 cm−2 of CO at 850 °C and an applied voltage of 1.8 V, which is 168 % higher than that of a pure SFM electrode. In addition, no carbon deposits were observed at the end of the reaction. The co-doping strategy delivered enhanced performance without degradation over 100 h of high-temperature operation, which suggests that it is a reliable cathode material for CO2 electrolysis. This study introduced an innovative method for improving the SOEC-electrode microstructure and developing efficient electrocatalysts for CO2 electrolysis.

Influence of Copper-Iron (CuFe) and Copper-Tin (CuSN) alloys over mechanical strength properties in crimping process

This study investigates the comparative performance of Copper-Iron (CuFe) and Copper-Tin (CuSn) alloys in crimping processes, with a focus on their mechanical, electrical, and corrosion-resistance properties. Crimping is a critical method for creating reliable electrical and mechanical connections, particularly in environments subjected to significant mechanical stress and varying temperatures [1]. CuFe alloys, known for their superior mechanical strength and hardness, present challenges in crimping due to their increased resistivity and reduced ductility. Conversely, CuSn alloys offer a balance between electrical conductivity, ease of crimping, and corrosion resistance, making them a preferred choice in many industrial applications. This research aims to provide a comprehensive analysis of how the distinct properties of CuFe and CuSn alloys influence the crimping process, ultimately guiding material selection for optimized performance in various applications [2]. Experimental data will be drawn from tensile strength tests, electrical resistance measurements, and corrosion tests, providing a holistic understanding of the advantages and limitations of each alloy.

Magnetostrictive Behavior of Severe Plastically Deformed Nanocrystalline Fe-Cu Materials

Reducing the saturation magnetostriction is an effective way to improve the performance of soft magnetic materials and reduce core losses in present and future applications. The magnetostrictive properties of binary Fe-based alloys are investigated for a broad variety of alloying elements. Although several studies on the influence of Cu-alloying on the magnetic properties of Fe are reported, few studies have focused on the effect on its magnetostrictive behavior. High pressure torsion deformation is a promising fabrication route to produce metastable, single-phase Fe-Cu alloys. In this study, the influence of Cu-content and the chosen deformation parameters on the microstructural and phase evolution in the Fe-Cu system is investigated by scanning electron microscopy and synchrotron X-ray diffraction. Magnetic properties and magnetostrictive behavior are measured as well. While a reduction in the saturation magnetostriction λs is present for all Cu-contents, two trends are noticeable. λs decreases linearly with decreasing Fe-content in Fe-Cu nanocomposites, which is accompanied by an increasing coercivity. In contrast, both the saturation magnetostriction as well as the coercivity strongly decrease in metastable, single-phase Fe-Cu alloys after HPT-deformation.

Investigation of converter copper slag reduction using spent cathode carbon as a reductant

ABSTRACT Aiming to address the difficulty of harmless treatment of fluorine in spent cathode carbon (SCC) and high metal content in copper slag, a new method of sustainable production of Fe-Cu alloys by reducing converter copper slag with SCC is proposed. Thermodynamic studies show that Fe-Cu alloys can be obtained at temperatures higher than 1250 °C and fluorine can be effectively fixated. Feasibility experiments were carried out in conjunction with theoretical analyses to clarify the feasibility of the method. At 1500 °C, the recovery of copper and iron reached 93.37% and 78.51%, respectively. During the smelting process, the iron-bearing phases in the slag forms Fe-Cu alloys with copper under high temperatures reducing conditions, and the fluorine is fixated in the slag through conversion to CaF2. This method achieves the effective utilisation of SCC during the reduction smelting process. The phase transformation and thermodynamics of the reduction process were investigated, and reaction mechanism was revealed. The process provides new ideas and perspectives for the environmentally sound treatment of SCC through a pyrometallurgical processes.

The Study of the Electrochemical Corrosion Behavior of Cu-30%Fe Nanoalloy

In this work, we have developed Cu-Fe alloys with a nanometric structure through the process of mechanosynthesis. We then followed the formation mechanism of these alloys and proceeded with a crucial step, which is cold compaction. We have elaborated Cu-Fe alloys with a nanometric structure by mechanosynthesis and following the mechanism of formation of these alloys, the we employed various analytical techniques to characterize the structural and microstructural properties of our powders. The X-ray diffraction method (XRD) was used to calculate the structural parameters, while laser granulometry was employed to study the evolution of particle size. Scanning electron microscopy (SEM) was then utilized to examine the morphology of the powders. Additionally, we investigated the electrochemical behavior of our alloys, focusing on their corrosion resistance. Electrochemical impedance spectroscopy (EIS) was performed in the frequency range of 10 kHz to 15 mHz to evaluate the corrosion performance.

Effects of energetic electron irradiation on electric, magnetic, and mechanical properties of Cu-1.2 at.%Fe alloy

Cu-1.2 at.% Fe samples were irradiated with 1.5 MeV electrons at 333 K and 448 K. Effects of the irradiation were observed as an increase in electrical conductivity and magnetization. In contrast, the Vickers hardness was little changed by the irradiation. The experimental results were explained as due to small Fe-rich clusters produced through radiation-enhanced diffusion. The present study shows that electron irradiation provides a fine control of the magnetic and electric properties of the Cu-Fe alloy.

Corrosion resistant high entropy conventional alloy (HECA) with superior work hardenability

Cu-based alloys are known for their high corrosion resistance but with a lack of processing ability and vice versa. Here we present a novel alloy design concept realizing Cu-rich high entropy conventional alloy (HECA) having exceptional corrosion resistance (Ecorr = - 0.27 V, icorr = 2.83 × 10−6 A/cm2) and work hardenability (strength = 413 MPa, total elongation = 28 %) synergy simultaneously in as-fabricated state. This cocktailing effect in HECA (Cu-12Fe-8Mn-7.5Co-2.5Cr, all in at%) is attributed to the formation of Fe-Mn-Co-Cr containing high entropy phase (HEP) in the Cu-rich matrix. A pronounced two-phase hardening by hetero-deformation induced (HDI) strengthening effect at the HEP/Cu matrix resulted in excellent work hardenability whereas, exceptional corrosion resistance was attributed to delayed corrosion kinetics owing to the preferential corrosion of the Cu-rich phase over HEP in HECA. Thus, Cu-rich HECA overcomes the corrosion-strength ductility dilemma in Cu-rich alloys when compared with classical binary Cu-Fe alloys in an as-fabricated state.

Reduction of Copper Smelting Slag by Carbon for Smelting Cu-Fe Alloy

Reduction of Copper Smelting Slag by Carbon for Smelting Cu-Fe Alloy

Numerical method determining the time-dependent position of a minority phase sphere in the Fe-Cu alloy droplet

Abstract A numerical method was developed to track the dynamic positions of the L2 phase sphere inside the Fe-Cu alloy droplet. Firstly, the temperature field distribution within alloy droplet was calculated, and the variation in thermal gradient was analyzed. Secondly, the migration behavior of the sphere was analyzed based on Marangoni convection. Finally, the theoretical position of the 10 μm sphere was determined. The results demonstrated that there is a little difference in temperature between the center and the surface of the droplet, but its gradient is very different. Moreover, the maximum migration times for the L2 phase sphere were determined to be ~0.02 s, 0.07 s, and 0.14 s within 300μm, 600μm, and 900μm alloy droplets, respectively. In addition, it was also found that the same-sized spheres can reach the same relative position, i.e., 0.485R. This means the final position of the sphere within the different alloy droplets is independent of the droplet size.

Microstructure and properties of Cu-Fe alloy prepared by spray forming

Microstructure and properties of Cu-Fe alloy prepared by spray forming

Influence of minor Mg/Ca/Nb/Ag addition on the morphology and microstructure of Fe-rich phase in powder metallurgy Cu[sbnd]10Fe alloy

The effect of Mg/Ca/Nb/Ag alloying on the morphology and microstructure of powder metallurgy Cu10Fe alloy was investigated systemically in this work. Alloying of Ca reduces the size of Fe-rich particles, while alloying of Mg/Nb/Ag increases the Fe-rich particles. This is attributed to the different roles of various alloying elements on the liquid-phase separation behaviors as well as diffusion of Fe atoms during the solidification. Coarse size spherical Fe-rich particles with a face centered cubic structure are observed in CuFe alloys bearing Mg/Ag/Nb, whilst the alloying of Ca favors the formation of fine spherical Fe-rich particles with a body centered cubic structure. The factor governing the morphology is found to be interfacial energy for CuFe alloys containing Mg/Ag/Nb and elastic energy for Cu-Fe-Ca alloy, respectively. Coarse size Fe-rich particles are hard to deform during subsequent rolling, but the fine Fe-rich particles can co-deform with Cu matrix. This study could provide a detailed picture regarding the influence of various alloying element types on the size, morphology, and lattice structure of Fe phase of CuFe alloy.

Construction of MOF-74 derived CuFe/C alloy highly dispersed on ultrathin single layered reduced graphene for electrochemical determination of paracetamol

Paracetamol (PAT) is a widely used drug for fever reduction and pain relief, but its accumulation due to overuse can lead to detrimental effects on human health and environment. Here, a novel composite material CuFe/C@rGO with excellent electrochemical properties was successfully constructed by loading carbon-encapsulated CuFe alloy (CuFe/C) on ultrathin single layered reduced graphene oxide (rGO) surface for PAT detection. Firstly, the CuFe/C nanoparticles was derived from MOF-74 as bimetallic ‘preassembly platform’ to obtain high dispersiveness, huge accessible surface area, and uniform pore structure of the resulted material. And then the CuFe/C was uniformly dispersed on rGO to effectively avoid the aggregation of CuFe/C and increase the conductivity of composite material. In virtue of the synergistic effect of CuFe/C and rGO, the composite material modified glassy carbon electrode CuFe/C@rGO/GCE would be endowed with abundant electrocatalytic acitive sites and fast charge transfer speed between electrode surface and analyte. Expectedly, the CuFe/C@rGO/GCE shows outstanding sensing performance with wide linear ranges of 0.006–110 μM, low detection limit of 0.0015 μM (S/N=3), together with superior reproducibility, stability and anti-interference. This developed composite material as a flexible sensing platform can be used to detect PAT in real samples with a satisfactory recovery.

Effects of microalloying and magnetic annealing on microstructures and properties of magnetic immiscible copper matrix alloys

The magnetic immiscible copper matrix alloys are extensively industrial applications due to their comprehensive properties such as high strength, high conductivity, high thermal conductivity and excellent magnetic permeability. Here, we investigated the effects of the addition of Co and Al elements on the microstructural evolution of magnetic Cu–Fe alloys (CFAs) and comprehensive properties after annealing under the static magnetic field (SMF). The results show that the microalloying was effective in enhancing the mechanical and magnetic properties but negative for the electric conductivity. The addition of Co element significantly suppressed the grains recrystallization of CFAs during the annealing process and improved the thermal stability of CFAs. Al elements homogeneously dispersed in the sample. SMF facilitated the nucleation and precipitation processes of the secondary precipitated particles in the Cu-rich matrix through the introducing the extra magnetic Gibbs free energy and also promoted the structural transformation of the secondary precipitated particles from FCC to BCC. This work indicates that SMF can be effectively used to modify the magnetic materials with exceptional comprehensive properties during the solid state phase transformation process. It also provides valuable guidance for the development of novel materials with superior comprehensive performance.

Corrosion resistance of Cu-Fe deformation processed in situ alloy in chloride ion environment

To assess the corrosion resistance of Cu-Fe deformation in situ alloys in a chloride ion environment, Cu-Fe alloys with varying Fe contents (5 wt%, 10 wt%, and 14 wt%) were prepared using vacuum induction melting, and the impact of Fe content on the corrosion resistance was examined. The corrosion morphology and corrosion products were analyzed, and the corrosion rate, corrosion period, dynamic potential polarization curves, electrochemical parameters, and electrochemical impedance spectra with different Fe contents were determined. However, the corrosion resistance of Cu-Fe alloys initially increased with an increase in Fe content before decreasing, with Cu-10 wt% Fe alloys (95% reduction rate) exhibiting the best corrosion resistance. As the Fe content increased, the amount of primary Fe phase gradually increased and became more densely distributed. This led to an increase in the dense oxide film on the surface, thereby enhancing the corrosion resistance of the material. Moreover, with a further increase in Fe, the primary Fe phase exhibited coarsening and non-uniform distribution. This resulted in the oxide film becoming looser, leading to a decreased corrosion resistance of the alloy.

Precipitation kinetics of Cu in FeCu and FeCuX (X=B, N, and BN) alloys using kinetic Monte Carlo simulations

We employed kinetic Monte Carlo simulations to investigate the precipitation of Cu in FeCu and FeCuX (X=B, N, and BN) alloys. The parameters of kinetic Monte Carlo simulations were obtained through first-principles calculations. In this study, we utilized a vacancy-mediated model that considers the migration barriers dependent on local impurity atomic environments. The dynamical stability of both FeCu and FeCuX (X=B, N, and BN) alloys was examined by the virtual crystal approximation method. Through the assessment of advancement factor, cluster number density, and mean cluster radius, the simulation results indicated that both B and N promote precipitation of Cu. While B doping has a minor effect, N doping significantly promotes Cu precipitation.

3D morphology of the petal-like precipitates in Cu-Fe alloys: Experimental study and phase field modelling

Precipitation hardening is a well-known phenomenon which is widely harnessed in alloy design strategy. In particular, the microstructural features such as shape, size, precipitate number density and volume fraction determine the mechanical behaviour of materials. During service, the morphology of precipitates sometimes achieves a complex 3D shape upon displaying branching and/or splitting patterns. Unfortunately, the detailed information about this intricate morphology cannot be retrieved through traditional experimental techniques based on 2D visualization. Here, we report the implementation of a 3D analysis technique combining Focused Ion Beam (FIB) and Scanning Electron Microscopy (SEM) tomography to visualize the atypical petal-like morphology of Fe-rich precipitates in a Cu-Fe alloy. Using Phase-Field modelling (PFM), we identify the mechanism responsible for the unusual morphologies of Fe-rich particles. Our work highlights the significance of 3D characterization of precipitates and provides a fascinating pathway for refining understanding of precipitation mechanisms in metals and alloys.

Study on the Re-Aging Behavior of Cu-Rich Precipitates in a FeCu Alloy under Electropulsing.

The nanoscale Cu-rich precipitates (CRPs) are one of the most critical microstructural features responsible for degrading the mechanical properties of reactor pressure vessel (RPV) steels. The prospect of the rapid regeneration of the service performance of degraded materials through electropulsing is attractive, and electropulsing has been proven to have the application potential to eliminate the CRPs and recover the mechanical properties of RPV materials. However, few studies have investigated the secondary service issue of electropulsing. This paper provides experimental findings from microstructural investigations and property evaluations of a FeCu RPV model alloy subjected to re-aging following recovery electropulsing and annealing treatments. The evolution behavior of CRPs and the changes in the hardness of the alloy during the re-aging process after electropulsing treatment were consistent with the initial aging process, while the re-aging process of the annealing treatment group was quite different from the initial aging. The difference between the electropulsing and annealing treatment groups was that the annealing treatment failed to eliminate the precipitates completely, leaving behind some large precipitates. This work demonstrates the potential application of EPT in this field.

Introducing a novel catalyst for efficient conversion of CO2 into syngas through reverse-water-gas-shift (RWGS) reactions based on highly mesoporous structures MCM-41: Influence of the Fe incorporation

The RWGS is the first step in CO2 hydrogenation. This process converts CO2 into valuable compounds, such as methanol, to address the global issue of CO2 emissions. In this research, the performance of a Cu-Fe bimetallic catalyst mounted onto MCM-41 support in RWGS was investigated. Our results demonstrate that MCM-41′s high specific surface area is advantageous for dispersing active metals and preventing their sintering. The Cu-Fe supported on MCM-41 samples are characterized by Scanning Electron Microscopy (SEM), ex situ X-ray Diffraction (XRD), Brunner–Emmet–Teller (BET), and Temperature Programmed Reduction (TPR). In order to investigate the catalytic activity, key variables including a temperature range of 400–600 °C, different H2/CO2 ratios, and various gas hourly space velocities (GHSV) at atmospheric pressure were assessed. In this study, excellent CO2 conversion was attained at a high GHSV (96,000 ml g-1h−1), which is advantageous for the design of smaller reactor volumes. In comparison to industrial Copper-Zinc catalysts and iron-free copper-supported MCM-41 catalysts, which suffer from a high sintering rate at temperatures above 300 °C, adding Iron (Fe) to the copper could increase the catalyst's activity and stability in terms of CO2 conversion and CO selectivity due to the formation of a Cu-Fe alloy. The novelty of this study lies in the assessment of the benefits afforded by bimetallic Cu-Fe catalysts in conjunction with high surface area MCM-41. Also, three different ratios of Cu-Fe (10-1, 7-1, 4-1) were considered for our experiments. The Cu-Fe = 10-1 ratio reached the highest CO2 conversion and CO selectivity value in 600 °C with amounts of 49 % and 99.7 %, respectively.

Effect of cryorolling on microstructure evolution and mechanical properties of spray deposited Cu-Fe alloy

In order to solve or suppress the problem of macro segregation of Fe phase of Cu-Fe alloy in the traditional casting process, we successfully prepared Cu-10Fe alloy prefabricated slabs with homogeneous and fine microstructure by spray deposition and achieved high strength Cu-10Fe alloy thin strips by subsequent cryorolling. Cryorolling was carried out at different reductions to investigate the relationship between microstructure evolution and mechanical properties. The results show that the spray deposited alloys have good plasticity and low temperature workability. As the reduction increased, the Fe phase becomes more fibrous and the average grain size of the alloy is refined to 0.35 μm. The {112}<111> texture was gradually transformed into a stabilized {110}<112> texture during cryorolling suggested that the low temperature suppressed cross-slip and improved the strength of the alloy. The mechanical properties of the alloys improved significantly after cryorolling is mainly attributed to the significant grain refinement, dislocation accumulation and the presence of ultrafine grains during the cryorolling process. The successful development of thin strips of Cu-Fe alloy with uniform distribution of Fe phase and high strength provides a new idea for the preparation of thin strips of immiscible alloys such as Cu-Fe alloy.