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1
Kouba, R., M. Keddam, and M. E. Djeghlal. "A diffusion–precipitation model for gaseous nitriding of Fe-2wt.% V alloy." Journal of Alloys and Compounds 536 (September 2012): 124–31. http://dx.doi.org/10.1016/j.jallcom.2012.04.114.
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Hosmani, S. S., R. E. Schacherl, and E. J. Mittemeijer. "Nitriding behavior of Fe–4wt%V and Fe–2wt%V alloys." Acta Materialia 53, no. 7 (2005): 2069–79. http://dx.doi.org/10.1016/j.actamat.2005.01.019.
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Hug, E., O. Hubert, and J. J. Van Houtte. "Effect of internal stresses on the magnetic properties of non-oriented Fe–3wt.% Si and (Fe,Co)–2wt.% V alloys." Materials Science and Engineering: A 332, no. 1-2 (2002): 193–202. http://dx.doi.org/10.1016/s0921-5093(01)01722-1.
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Xiao, Yi Feng, Zhi Wei Hou, Fang Tang, Jian Xun Gong, and Yue Hui He. "Effects of Vanadium on Microstructure and Properties of a Fe-Cr-W-Mo-V Overlaying Alloy." Advanced Materials Research 750-752 (August 2013): 2048–51. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.2048.
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A Fe-Cr-W-Mo-V overlaying alloy was prepared on Q235 steel by SMAW with different Fe-V powders added in electrode coating. Effects of vanadium on microstructure, hardness and wear resistance of the alloy were studied with SEM, OM, hardness and wear test. The results show that Fe-V powders content affects welding crack number, which increasing quickly at 0-2%(wt, as fellow), decreasing slowly at 2-20%, disappearing above 22%. With the increase of Fe-V, vanadium-rich carbides number increase, the grain size and hardness increase firstly then decrease above 2, at 20% gain the highest. Conversely, the wear loss decreases slowly first, then increases quickly above 2, wear resistance is the best at 20-22%.
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Yasuda, Hiroyuki Y., Tsuyoshi Furuta, and Takenori Maruyama. "Effect of Third Elements on Pseudoelasticity in Fe3Ga Alloys." Materials Science Forum 706-709 (January 2012): 2032–37. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.2032.
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Pseudoelasticity of Fe3Ga polycrystals doped with third elements (Ti, V, Cr, Mn, Co, Ni, Si, Ge) was examined. Fe3Ga polycrystals with the appropriate heat treatment were found to exhibit large pseudoelasticity based on reversible motion of dislocation dragging an antiphase boundary (APB). In Fe3Ga crystals with the D03 superlattice structure, paired 1/4<111> superpartial dislocations mainly moved dragging the next-nearest-neighbor APB during loading. During unloading, the APB pulled back the superpartial dislocations resulting in the pseudoelasticity. The D03 ordered phase also developed in Fe3Ga polycrystals with 2at% of the third elements. However, the strain recovery of Fe3Ga polycrystals depended strongly on third element. Fe3Ga polycrystals doped with 2at% of Mn, Cr and Co demonstrated large pseudoelasticity. In contrast, the other doped elements decreased the amount of strain recovery. The frictional stress of 1/4<111> superpartial dislocations and the back stress due to the APB, acting on the dislocations, changed by doping the third elements, which was closely related to the pseudoelastic behavior. It is also noted that there was a good correlation between the APB back stress and the ordering temperature from the B2 to D03 phase.
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Karakchieva, N. I., T. V. Dement, and I. A. Kurzina. "PRODUCTION AND STUDY OF RADIATION-RESISTANT COMPOSITE MATERIAL BASED ON V-TI-CR AND FERRITE STEEL 17CR-12NI-FE." Materials Science, no. 10 (2022): 9–20. http://dx.doi.org/10.31044/1684-579x-2022-0-10-9-20.
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The study results of specimens of a three-layer material «ferrite steel 17Cr-12Ni-Fe / vanadium alloy / ferrite steel 17Cr-12Ni-Fe» obtained by laser growth are presented. The structural-phase state, strength properties of the vanadium alloy and three-layer alloy in the initial state, after heat treatment at 1700 °С, and also after irradiation have been investigated. The interaction zone of the vanadium alloy and steel wasstudied in detail.
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Divinski, S. V., Y. S. Kang, J. S. Lee та Chr Herzig. "Bulk and grain boundary diffusion of Ag in γ-FeNi alloy". International Journal of Materials Research 94, № 9 (2003): 949–53. http://dx.doi.org/10.1515/ijmr-2003-0173.
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Abstract Solute diffusion of Ag in polycrystalline γ-Fe-40 wt.% Ni alloy was studied by means of the radiotracer technique. For bulk and grain boundary diffusion, the following Arrhenius parameters were established: D v 0 = 1.2 × 10 − 3 m 2 / s $ D_v^0 = 1.2 \times {10^{ - 3}}{m^2}/s $ and Q v = 279 kJ/mol and P 0 = 8:1 ⨯ 10–14 m3/s and Q gb = 126 kJ/mol, respectively. The diffusion profiles reflect the very low Ag solid solubility which was estimated in the alloy via the specific activity of the applied 110mAg radiotracer.
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Belevskii, Stanislav, Serghei Silkin, Natalia Tsyntsaru, Henrikas Cesiulis, and Alexandr Dikusar. "The Influence of Sodium Tungstate Concentration on the Electrode Reactions at Iron–Tungsten Alloy Electrodeposition." Coatings 11, no. 8 (2021): 981. http://dx.doi.org/10.3390/coatings11080981.
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The investigation of Fe-W alloys is growing in comparison to other W alloys with iron group metals due to the environmental and health issues linked to Ni and Co materials. The influence of Na2WO4 concentration in the range 0 to 0.5 M on bath chemistry and electrode reactions on Pt in Fe-W alloys’ electrodeposition from citrate electrolyte was investigated by means of rotating disk electrode (RDE) and cyclic voltammetry (CV) synchronized with electrochemical quartz crystal microbalance (EQCM). Depending on species distribution, the formation of Fe-W alloys becomes thermodynamically possible at potentials less than −0.87 V to −0.82 V (vs. Ag/AgCl). The decrease in electrode mass during cathodic current pass in the course of CV recording was detected by EQCM and explained. The overall electrode process involving Fe-W alloy formation may be described using formalities of mixed kinetics. The apparent values of kinetic and diffusion currents linearly depend on the concentration of Na2WO4. Based on the values of partial currents for Fe and W, it was concluded that codeposition of Fe-W alloy is occurring due to an autocatalytic reaction, likely via the formation of mixed adsorbed species containing Fe and W compounds or nucleation clusters containing both metals on the electrode surface.
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Stan, K., L. Litynska-Dobrzynska, P. Ochin, A. Wierzbicka-Miernik, A. Góral, and J. Wojewoda-Budka. "Effect of Alloying Elements on Microstructure and Properties of Al-Mn-Fe Ribbon." Archives of Metallurgy and Materials 58, no. 2 (2013): 341–46. http://dx.doi.org/10.2478/v10172-012-0195-0.
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Influence of Ti, V, Cr, Zr, and Mo additions on microstructure and mechanical properties of the Al91Mn7Fe2 quasicrystalline alloy produced by the melt spinning technique has been studied. It was found that the microstructure of obtained all ribbons was similar and consists of spherical or dendritic icosahedral quasicrystalline particles embedded in an aluminium matrix coexisting with small fraction of intermetallic phase. Comporing DSC curves obtained for each sample it was observed that the alloy with Mo addition exhibits the best thermal stability among prepared alloys. Addition of molybdenum caused a significant shift of the main exothermic peak corresponding to temperature of quasicrystalline phase decomposition from 450ºC for ternary alloy to about 550ºC for quaternary composition. Microhardness measured for all prepared alloys were similar with the mean value of about 200 HV only alloy with Zr addition exhibited higher microhardness of about 270 HV caused by strengthening effect of Zr localized in the grains of aluminium matrix.
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Chilimoniuk, Paulina, Marta Michalska-Domańska, and Tomasz Czujko. "Formation of Nanoporous Mixed Aluminum-Iron Oxides by Self-Organized Anodizing of FeAl3 Intermetallic Alloy." Materials 12, no. 14 (2019): 2299. http://dx.doi.org/10.3390/ma12142299.
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Nanostructured anodic oxide layers on an FeAl3 intermetallic alloy were prepared by two-step anodization in 20 wt% H2SO4 at 0 °C. The voltage range was 10.0–22.5 V with a step of 2.5 V. The structural and morphological characterizations of the received anodic oxide layers were performed by field emission scanning electron microscopy (FE-SEM). Therefore, the formed anodic oxide was found to be highly porous with a high surface area, as indicated by the FE-SEM studies. It has been shown that the morphology of fabricated nanoporous oxide layers is strongly affected by the anodization potential. The oxide growth rate first increased slowly (from 0.010 μm/s for 10 V to 0.02 μm/s for 15 V) and then very rapidly (from 0.04 μm/s for 17.5 V up to 0.13 μm/s for 22.5 V). The same trend was observed for the change in the oxide thickness. Moreover, for all investigated anodizing voltages, the structural features of the anodic oxide layers, such as the pore diameter and interpore distance, increased with increasing anodizing potential. The obtained anodic oxide layer was identified as a crystalline FeAl2O4, Fe2O3 and Al2O3 oxide mixture.
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Lee, JUN HA, In Gyeong KIM, Se Eun Shin, and Yong-bum Park. "Effect of Ni Concentration on Physical Properties in Electroformed Fe-Ni Alloy for ACC of Secondary Battery." ECS Meeting Abstracts MA2024-01, no. 53 (2024): 2782. http://dx.doi.org/10.1149/ma2024-01532782mtgabs.
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The anode current collectors (ACC) work as a support for electrode materials. They are also electrical conductors between electrode and external circuits. Usually copper ∙ nickel ∙ titanium ∙ 304 stainless steel materials are used as ACC due to high electrical conductivity, high mechanical and thermal stability in the potential range of 0~2.96 V. Contrary to copper and nickel, electroformed Fe-Ni alloy is a promising materials due to obtain such as high mechanical strength, low cost, and producing very thin ACCs. In the current work, Fe-Ni alloys were electroformed by employing batch-type electrodeposition simulating the drum-type cathode for continuous electroforming equipment. During thermo-mechanical anneaing, the decrease lattice parameter of the γ phase occurred and AGG were observed on electroformed Fe-40~80 wt.% Ni alloys. The current work has been aimed at investigating the effect of the Ni concentration on the physical properties of the electroformed Fe-Ni alloy.
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Wang, Ya Rong, Yang Yu, and Wei Chao Zhang. "Welding-Brazing Characteristic in Electron Beam Joining Vanadium Alloy and Stainless Steel." Advanced Materials Research 1088 (February 2015): 130–34. http://dx.doi.org/10.4028/www.scientific.net/amr.1088.130.
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The high vacuum electron beam welding-brazing was used to joining vanadium alloy (V-5Cr-5Ti) with stainless–steel (HR-2). The temperature fields and stress distributions in the V-5Cr-5Ti/HR-2 joint during the welding process were numerically simulated and the effect of the electron beam off-set distance was studied. The results show that the accurate heat input and proper molten pool position can help to control the fusion ratio of the V/Fe. The electron beam should off set on the stainless steel side rather than vanadium alloy side, and the best range of the distances off-set is 0-0.5mm. The residual stress appears to be bimodal and asymmetric. The maximum lateral residual tensile stress reached 388MPa at the V-5Cr-5Ti side. The joints with the characters of welding and brazing and the metallurgically bonded joint was achieved with 0.3mm beam off-set. With the liquid-to-solid interalloying of dissimilar materials controlled well, a reaction zone is gained on the interface. The maximum tensile strength of vanadium alloy/stainless-steel dissimilar alloy jointswas up to 200MPa with no defect.
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Niitsu, Kodai, and Ryosuke Kainuma. "Effect of Microalloying Elements on Solidification Microstructure of the La(Fe0.89Si0.11)13 Alloy." Key Engineering Materials 508 (March 2012): 172–77. http://dx.doi.org/10.4028/www.scientific.net/kem.508.172.
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The Effect of Microalloying Elements and Compounds, such as Be, B, C, P, S, Ti, V, Cu, Zn, in, BN, VN, Mn3N, LaN, MnS and Ti4C2S2, Ranging in Amount from 0.005 to 0.2 at.%, on the α-Fe + FeLaSi Two-Phase Microstructure of a La(Fe0.89Si0.11)13 as-Melted Specimen Was Investigated. The Addition of Mn3N Was Found to Contribute to α-Fe Grain Refinement to a Certain Extent, but to Harm the Uniform Growth of the τ1 Phase in the Stage of Subsequent Annealing.
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Almeshaiei, Eisa A., Lubanah Ahmad, and Ibrahim Elgarhi. "Improving the Life Service of Fe-34Mn-10Al-0.76C Tidal Turbine Blades Using Variable PMF." Journal of Materials Science Research 11, no. 1 (2022): 40. http://dx.doi.org/10.5539/jmsr.v11n1p40.
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This paper studied the effect of increasing pulsed magnetic field (PMF) voltage during treating a Fe-34Mn-10Al-0.76C steel alloy used in fabricating a blade to be installed in a tidal turbine on its fatigue lifetime. Fatigue strength for each sample treated using PMF voltages (0, 100 and 160 V) had been investigated experimentally to plot their S-N curves while fatigue lifetime of the tidal turbine had been predicted using mathematical model established by a MATLAB code. The cyclic loadings affect the studied turbine were rearranged using Rainflow algorithm. Results of the study showed that, the blade made of Fe-34Mn-10Al-0.76C steel alloy and treated using PMF 100 v had achieved the highest fatigue resistance. The aforementioned fact had investigated based on comparing among the three specimens under the same conditions. For each specimen, the effect of the tidal turbine operation period according to fatigue lifetime been examined as well and it was investigated that, increasing number of operation hours resulted in a drastic reduction in the turbine&rsquo;s fatigue life of the turbine.
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Le Pimpec, F., O. Gröbner, and J. M. Laurent. "Electron stimulated molecular desorption of a non-evaporable Zr–V–Fe alloy getter at room temperature." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 194, no. 4 (2002): 434–42. http://dx.doi.org/10.1016/s0168-583x(02)01034-0.
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Kim, E. H., Hi Won Jeong, Seung Eon Kim, Yong Taek Hyun, Yont Tai Lee, and Jong Won Yoon. "Tensile Properties of Cast and Hot Isostatic Pressurized Ti-6Al-4Fe-xSi Alloys." Materials Science Forum 449-452 (March 2004): 689–92. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.689.
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A new high strength titanium alloy system with low cost alloying elements, such as Al, Fe, has been recently developed. In present study the expensive V was replaced with Fe, and Si was added from 0 to 7.5wt.%. The effect of Fe and Si on the microstructure and tensile properties of Ti-6Al-4Fe-xSi (x=0, 0.1, 0.25, 0.5, 0.75wt.%) alloys was investigated. The room and high temperature mechanical properties of Ti-6Al-4Fe alloys were better than those of the Ti-6Al-4V. It was mainly due to the phase boundary strengthening at ambient and high temperature. The strength and elongation of the developed alloys depended upon the Si contents. The Si elements made the grain boundary and colony size fine, and increased the strength of the developed alloys by solid solution and precipitation hardening. The tensile strength variation with the Si contents at room temperature and 400°C, and at 450°C and 500°C showed a similar behavior, respectively.
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Yoshimura, K., A. Miyazaki, R. Vijayaraghavan, and Y. Nakamura. "Hyperfine field of the Co2YZ Heusler alloy (Y = V, Cr, Mn and Fe; Z = Al and Ga)." Journal of Magnetism and Magnetic Materials 53, no. 1-2 (1985): 189–98. http://dx.doi.org/10.1016/0304-8853(85)90149-0.
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Магомедов, М. Н. "Изучение свойств сплава золото-железо в макро- и нанокристаллических состояниях в различных P-T-условиях". Физика твердого тела 62, № 12 (2020): 2034. http://dx.doi.org/10.21883/ftt.2020.12.50206.172.
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For a disordered fcc-Au-Fe substitution alloy, the parameters of the Mie–Lennard-Jones pairwise interatomic potential are determined. Based on these parameters, the concentration dependencies of lattice properties for the macrocrystal of this alloy are calculated. Calculations of 20 properties of macrocrystals fcc-Au, fcc-Fe and fcc-Au0.5Fe0.5 are showed good agreement with experimental data. Using the RP-model of the nanocrystal, the state equation P(v, T; N) and baric dependences of both lattice and surface properties of the fcc-Au0.5Fe0.5 alloy are calculated. Calculations were performed at temperatures T = 100, 300 and 500 K for both a macrocrystal (N = Macro) and a cubic nanocrystal with N = 306 atoms. It is shown that with an isothermal-isobaric (P = 0) decrease in the size of a nanocrystal, its the Debye temperature, elastic modulus, and specific surface energy decrease, while its the specific volume, thermal expansion coefficient, specific heat capacity, and Poisson's ratio increase. At low temperatures in a certain pressure region, the specific surface energy increases at an isothermal-isobaric decrease in the number of atoms in the nanocrystal. As the temperature increases, this pressure region disappears.
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Guo, Chun, Guangcan Huang, Ruizhang Hu, et al. "The Design and Preparation of New Fe(21-x)CoNiCuAlTix High-Entropy-Alloy Wear- and Corrosion-Resistant Coatings and an Investigation of Their Performance." Coatings 15, no. 4 (2025): 396. https://doi.org/10.3390/coatings15040396.
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The purpose of this study is to prepare new Fe(21-x)CoNiCuAlTix alloy coatings and to investigate the phase composition, microstructure, wear resistance, and corrosion resistance of these high-entropy-alloy coatings with varying Ti content. High-entropy Fe(21-x)CoNiCuAlTix (x = 0; 2; 4; 6; 8) alloy coatings were prepared on 65Mn steel substrates via laser cladding. The results showed that the addition of Ti promoted the formation of the BCC phase, which increased the hardness of the coatings and improved their wear resistance due to the hardening of the solid solution and grain refinement. The microhardness of the coating was 689.08HV0.2 at x = 8, 2.056 times that of the base metal, and the wear resistance was 2.565 × 10−7 g/(N·m). The corrosion potential and corrosion current density were −0.199 V and 3.513 × 10−7 A/cm2, respectively, indicating excellent corrosion resistance. The addition of titanium significantly enhanced the formation of the BCC phase, improved the microstructure through solid-solution hardening and grain refinement, and caused lattice distortion. These effects, as well as the formation of solid bonds, significantly improved the wear and corrosion resistance of the coatings.
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Ramezannejad, Neda, and Hamidreza Farnoush. "Effect of graphene oxide on micro-tribological and electrochemical properties of electrophoretically deposited HA-TiO2-GO composite coatings." Processing and Application of Ceramics 16, no. 1 (2022): 30–41. http://dx.doi.org/10.2298/pac2201030r.
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In the present study, hydroxyapatite-titania-graphene oxide (HA-TiO2-GO) nanostructured ternary composites were deposited on Ti-6Al-4V alloy by using electrophoretic deposition. The well-dispersed stable suspensions of hydroxyapatite particles with 20wt.% TiO2 and 0, 0.5, 1 and 2 wt.% GO were prepared and electrophoretic deposition was performed at an optimum voltage of 20 V for 90 s. A novel linear approach of fracturemechanics was applied to evaluate the fracture toughness of the coatings from the recorded forces and depth of penetration by using an incremental-load micro-scratch technique. The distances and contact pressures indicating crack formation and coating spallation, as well as the value of fracture toughness were obtained at the maximum level for the composite coatings with 20 wt.% TiO2 and 2 wt.% GO. The rapid apatite forming ability as well as improved corrosion resistance of the composite coatings with 20 wt.% titania and 2 wt.% GO were analysed by electrochemical impedance spectroscopy, SEM and XRD.
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Al-Zoubi, Noura. "Elastic Parameters of Paramagnetic Fe–20Cr–20Ni-Based Alloys: A First-Principles Study." Metals 9, no. 7 (2019): 792. http://dx.doi.org/10.3390/met9070792.
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The single-crystal and polycrystalline elastic parameters of paramagnetic Fe0.6−xCr0.2Ni0.2Mx (M = Al, Co, Cu, Mo, Nb, Ti, V, and W; 0 ≤ x ≤ 0.08) alloys in the face-centered cubic (fcc) phase were derived by first-principles electronic structure calculations using the exact muffin-tin orbitals method. The disordered local magnetic moment approach was used to model the paramagnetic phase. The theoretical elastic parameters of the present Fe–Cr–Ni-based random alloys agree with the available experimental data. In general, we found that all alloying elements have a significant effect on the elastic properties of Fe–Cr–Ni alloy, and the most significant effect was found for Co. A correlation between the tetragonal shear elastic constant C′ and the structural energy difference ΔE between fcc and bcc lattices was demonstrated. For all alloys, small changes in the Poisson’s ratio were obtained. We investigated the brittle/ductile transitions formulated by the Pugh ratio. We demonstrate that Al, Cu, Mo, Nb, Ti, V, and W dopants enhance the ductility of the Fe–Cr–Ni system, while Co reduces it. The present theoretical data can be used as a starting point for modeling the mechanical properties of austenitic stainless steels at low temperatures.
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Muradimova, L. F., A. M. Glezer, S. O. Shirshikov, I. V. Shchetinin, and D. L. Dyakonov. "Structural phase transformations during deformation Of Fe-Co-V alloys using the high-pressure torsion method." Vektor nauki Tol'yattinskogo gosudarstvennogo universiteta, no. 1 (2021): 16–23. http://dx.doi.org/10.18323/2073-5073-2021-1-16-23.
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Fe-Co alloys belong to the soft magnetic materials and have an extremely high value of saturation magnetization σ at room temperature. In particular, Fe-Co alloy with the equiatomic ratio of components at room temperature has the maximal σ value among all known ferromagnetic materials. Unfortunately, it is hard to reproduce the unique magnetic properties of these alloys (especially Fe-Co alloys) due to their high fragility caused mainly by the formation of far atomic ordering according to B2 type in the structure. Adding vanadium to the Fe-Co alloys increases plasticity, but it reduces basic magnetic characteristics. In this paper, using the X-ray structural analysis, transmission scanning microscopy, and magnetometry, the authors analyzed the influence of high-pressure torsion at the temperatures of 77 and 295 K on the structure and phase composition of soft magnetic alloys (Fe-Co)100-xVx (x=0–6.0). As the principal structural parameter before and after deformation, the authors analyzed the magnitude of γ-phase volume ratio in the BCC magnetic matrix. The study identified that plastic deformation causes the suppression of formation of excessive γ-phase in alloys containing (3.0–6.0) % V. The study shows that the loss of γ-phase is observed with the increase of high-pressure torsion deformation firstly in the alloys with the high vanadium proportion and at the deformation effect at higher temperature (295 K). The authors conclude that the detected effect is a consequence of γ→α martensite transformation caused by deformation by analogy to TRIP-effect. The study identified that the suppression of paramagnetic γ-phase leads to a noticeable increase in the specific saturation magnetization.
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Loureiro, S. A., Daniel Fruchart, Sophie Rivoirard, Dílson S. dos Santos, and L. M. Tavares. "Synthesis, Hydrogenation and Mechanical Milling of Pseudo-Binary Zr(NbxV1-x)2 (0≤x≤0.65) Alloys." Materials Science Forum 570 (February 2008): 45–51. http://dx.doi.org/10.4028/www.scientific.net/msf.570.45.
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AB2 metallic alloys provide large quantities of Laves phases when prepared using conventional thermal routes. In the present work the crystallography, hydrogenation behavior and mechanical milling (MM) effects of the pseudo-binary Zr(NbxV1-x)2 (0<x≤0.65) system are studied. It is found that the partial replacement of V by Nb atoms leads to the formation of cubic C15 (0<x≤0.20) and hexagonal C14 (0.35≤x≤0.65) Laves phases. For x≤0.20, the niobium additions promote a slight increase of the hydrogen storage capacity by the C15 phases. For 0.35≤x≤0.65, the reduction of the molar fraction of the C14 phase promotes an increase of the alloy hydrogen storage capability. Iron incorporation plays a major role on the type of final mechanically-milled Zr-Nb-V alloys obtained: a transformation from Laves phases (C14 and C15) to an fcc (Fm3m) one; while, in the absence of Fe, amorphization of the system was observed, as predicted by Miedema Model. As a general result, the mechanical milling of the Zr-Nb-V alloys results in a reduction of the hydrogen storage capacity, at least for long processing times.
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Majeed, Abdul, and Bastian J. M. Etzold. "Investigating the Stability of Electrodeposited NiMo Alloy for Hydrogen Evolution Reaction in Alkaline Media." ECS Meeting Abstracts MA2023-02, no. 42 (2023): 2088. http://dx.doi.org/10.1149/ma2023-02422088mtgabs.
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A lot of efforts have been devoted to develop highly active noble-metal-free catalysts for hydrogen production by water electrolysis.1,2 Nevertheless, the stability of such catalysts, yet equally important, is rarely touched. NiMo alloy is an emerging catalyst for hydrogen evolution reaction (HER) in alkaline media.3 In the present work, we studied the stability of NiMo alloy for HER under alkaline (1M KOH, Fe-free) conditions as a model catalyst. Using electrodeposition at room temperature, we deposited NiMo alloy onto nickel foam substrates. A long-term (20h) stability test at a fixed current density of -100 mA cm-2 was carried out using chronopotentiometry. Electrochemical active surface area (ECSA) and HER polarization curves were determined prior and after this stability test. Here, obvious activity loss is observed. The ECSA of NiMo catalyst after chronopotentiometry test increases by 10%. Thus, an obvious increase in the overpotential is observed upon normalizing the catalytic current with ECSA (Figure 1a). As further stability test 100 CV cycles at a scan rate of 100 mV s-1 from 0 to –350 mV vs. RHE were carried out, the catalysts then hold for 30 min at open circuit potential and again 100 CV cycles carried out. A clear drop in activity during the second 100 cycles is also observed here and especially at the higher current density of 60 mA cm-2 (Figure 1b). In summary, we found that NiMo, though active initially, loses its activity with time under HER conditions in alkaline media. References Vesborg, P. C. K.; Seger, B.; Chorkendorff, I. Phys. Chem. Lett. 2015, 6, 951– 957. Zou, X. X.; Zhang, Y. Soc. Rev. 2015, 44, 5148– 5180. Kuznetsov, V. V.; Gamburg, Y. D.; Zhulikov, V. V.; Krutskikh, V. M.; Filatova, E. A.; Trigub, A. L.; Belyakova, O. A. Electrochim. Acta 2020, 354, 136610. Figure 1
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Ding, Jian, Xin Liu, Yujiang Wang, et al. "Effect of Sn Addition on Microstructure and Corrosion Behavior of As-Extruded Mg–5Zn–4Al Alloy." Materials 12, no. 13 (2019): 2069. http://dx.doi.org/10.3390/ma12132069.
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The effect of Sn addition on the microstructure and corrosion behavior of extruded Mg–5Zn–4Al–xSn (0, 0.5, 1, 2, and 3 wt %) alloys was investigated by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical measurements, and immersion tests. Microstructural results showed that the average grain size decreased to some degree and the amount of precipitates increased with the increasing amount of Sn. The extruded Mg–5Zn–4Al–xSn alloy mainly consisted of α-Mg, Mg32(Al,Zn)49, and Mg2Sn phases as the content of Sn was above 1 wt %. Electrochemical measurements indicated that the extruded Mg–5Zn–4Al–1Sn (ZAT541) alloy presented the best corrosion performances, with corrosion potential (Ecorr) and corrosion current density (Icorr) values of −1.3309 V and 6.707 × 10−6 A·cm−2, respectively. Furthermore, the corrosion mechanism of Sn is discussed in detail.
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Okazaki. "Characterization of Oxide Film of Implantable Metals by Electrochemical Impedance Spectroscopy." Materials 12, no. 21 (2019): 3466. http://dx.doi.org/10.3390/ma12213466.
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The oxide film resistance (RP) and capacitance (CCPE) diagrams of implantable metals (commercially pure Ti, four types of Ti alloys, Co–28Cr–6Mo alloy, and stainless steel) were investigated by electrochemical impedance spectroscopy (EIS). The thin oxide film formed on each implantable metal surface was observed in situ by field-emission transmission electron microscopy (FE-TEM). The Ti–15Zr–4Nb–1Ta and Ti–15Zr–4Nb–4Ta alloys had higher oxygen concentrations in the oxide films than the Ti–6Al–4V alloy. The thickness (d) of the TiO2 oxide films increased from approximately 3.5 to 7 nm with increasing anodic polarization potential from the open-circuit potential to a maximum of 0.5 V vs. a saturated calomel electrode (SCE) in 0.9% NaCl and Eagle’s minimum essential medium. RP for the Ti–15Zr–4Nb–1Ta and Ti–15Zr–4Nb–4Ta alloys was proportional to d obtained by FE-TEM. CCPE was proportional to 1/d. RP tended to decrease with increasing CCPE. RP was large (maximum: 13 MΩ·cm2) and CCPE was small (minimum: 12 μF·cm−2·sn−1, n = 0.94) for the Ti–15Zr–4Nb–(0 to 4)Ta alloys. The relative dielectric constant (εr) and resistivity (kOX) of the oxide films formed on these alloys were 136 and 2.4 × 106–1.8 × 107 (MΩ·cm), respectively. The Ta-free Ti–15Zr–4Nb alloy is expected to be employed as an implantable material for long-term use.
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Wang, Yihao, Limin Jia, Erhu Yan, et al. "Phase Equilibria of the V-Ti-Fe System and Its Applications in the Design of Novel Hydrogen Permeable Alloys." Membranes 13, no. 10 (2023): 813. http://dx.doi.org/10.3390/membranes13100813.
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The precise liquidus projection of the V-Ti-Fe system are crucial for designing high-performance hydrogen permeation alloys, but there are still many controversies in the research of this system. To this end, this article first uses the CALPHAD (CALculation of PHAse Diagrams) method to reconstruct the alloy phase diagram and compares and analyses existing experimental data, confirming that the newly constructed phase diagram in this article has good reliability and accuracy. Second, this obtained phase diagram was applied to the subsequent development process of hydrogen permeation alloys, and the (Ti65Fe35)100−xVx (x = 0, 2.5, 5, 10, 15, 25) alloys with dual-phase {bcc-(V, Ti) + TiFe} structure were successfully explored. In particular, the alloys with x values equal to 2.5 at.% and 5 at.% exhibit relatively high hydrogen permeability. Third, to further increase the H2 flux permeation through the alloys, a 500-mm-long tubular (Ti65Fe35)95V5 membrane for hydrogen permeation was prepared for the first time. Hydrogen permeation testing showed that this membrane had a very high H2 flux (4.06 mL min−1), which is ca. 6.7 times greater than the plate-like counterpart (0.61 mL min−1) under the same test conditions. This work not only indicates the reliability of the obtained V-Ti-Fe phase diagram in developing new hydrogen permeation alloys, but also demonstrates that preparing tubular membranes is one of the most important means of improving H2 flux.
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Terry, Brittney, and Reza Abbaschian. "Cooling Rate and Compositional Effects on Microstructural Evolution and Mechanical Properties of (CoCrCuTi)100−xFex High-Entropy Alloys." Entropy 26, no. 10 (2024): 826. http://dx.doi.org/10.3390/e26100826.
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This study investigates the impact of cooling rate and alloy composition on phase formations and properties of (CoCrCuTi)100−xFex (x = 0, 5, 10, 12.5, 15) high-entropy alloys (HEAs). Samples were synthesized using arc-melting and electromagnetic levitation, followed by quenching through the use of a Cu chill or V-shaped Cu mold. Cooling rates were evaluated by measuring dendrite arm spacings (DASs), employing the relation DAS = k ɛ−n, where constants k = 16 and n = ½. Without Fe addition, a microstructure consisting of BCC1 + BCC2 phases formed, along with an interdendritic (ID) FCC Cu-rich phase. However, with the addition of 5–10% Fe, a Cu-lean C14 Laves phase emerged, accompanied by a Cu-rich ID FCC phase. For cooling rates below 75 K/s, alloys containing 10% Fe exhibited liquid phase separation (LPS), characterized by globular Cu-rich structures within the Cu-lean liquid. In contrast, for the same composition, higher cooling rates of 400–700 K/s promoted a dendritic/interdendritic microstructure. Alloys with 12.5–15 at. % Fe displayed LPS irrespective of the cooling rate, although an increase in uniformity was noted at rates exceeding 700 K/s. Vickers hardness and fracture toughness generally increased with Fe content, with hardness ranging from 444 to 891 HV. The highest fracture toughness (5.5 ± 0.4 KIC) and hardness (891 ± 66 HV) were achieved in samples containing 15 at. % Fe, cooled at rates of 25–75 K/s.
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Zhou, Yu, Xian Yun Peng, Li Qiang Ji, and Yan Ping Fan. "Crystallographic and Electrochemical Performances of La0.73Ce0.27Ni3.25+xMn0.35Al0.15Cu0.75Fe0.25 (x = 0-0.75) Hydrogen Storage Alloys." Advanced Materials Research 772 (September 2013): 98–102. http://dx.doi.org/10.4028/www.scientific.net/amr.772.98.
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Microstructuresand electrochemical properties of La0.73Ce0.27Ni3.25+xMn0.35Al0.15Cu0.75Fe0.25 alloys are investigated. XRD results indicate that all alloys are identified with LaNi5 phase with CaCu5 type hexagonal structure, and lattice parameter a, c and cell volume V decrease with increasing x value. Maximum discharge capacity first increases from 286.4 mAh/g (x = 0) to 313.2 mAh/g (x = 0.25), and then decreases to 308.9 mAh/g (x = 0.75). High-rate dischargeability of the alloy electrodes increases when x increases from 0 to 0.75. HRD1200 increases with the increase in the I0 and D, and shows a linear relationship with the I0 and D.
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Gonzalez, Mario Alberto, and Michael Simpson. "(Invited) Consumable Fe Anode for Use in Direct Electrolytic Reduction of Spent Oxide Fuel." ECS Meeting Abstracts MA2023-01, no. 21 (2023): 1526. http://dx.doi.org/10.1149/ma2023-01211526mtgabs.
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The direct electrolytic reduction (DER) process can be used to reduce UO2 to U metal in a molten LiCl-Li2O electrolyte. In the baseline process, UO2 is loaded in a steel basket that serves as the cathode, while O2 gas is generated at a Pt anode. The use of Pt for anodes is non-optimal because of its cost and tendency to corrode via lithium platinate formation during the DER process. Other inert metals and cermets for DER anodes have been extensively researched to reduce the cost. Alternatively, reactive anodes may be considered that form disposable metal oxides rather than O2 gas. Thus, we investigated the behavior of pure iron rods as anodes for this process. Experiments were performed using a LiCl-2wt%Li2O electrolyte at 650oC in an Ar atmosphere glove box with <10 ppm O2 and H2O. UO2 powder was loaded into a stainless-steel cathode basket. A 7.56-mm diameter iron rod was used as the anode. Anode and cathode potentials were measured relative to a Ni/NiO reference electrode encased in a MgO tube with a porous MgO plug. The cell was run via controlled anode potential with increments from 0.2–1.0 V versus Ni/NiO. The headspace gas was sampled during experiments and analyzed for O2. Throughout the experiment, the cathode potential was consistent with either direct reduction of UO2 or reduction of Li2O, which forms Li that will also reduce UO2 to U metal. LECO oxygen analysis indicated 32% reduction of UO2 with a cell efficiency of 37%. Li2O concentration remained constant in the salt; thus, net oxidation must have occurred at the anode. The Fe anode was pulled out of the salt and photographed after stages of holding the potential at 0.2–1.0 V versus Ni/NiO in 0.1 V increments for about 11-12 min at each stage. Yet unidentified metal oxides were observed on the anode surface after holding at potentials of 0.4 V and 0.6–1.0 V. O2 was detected in the headspace gas when the anode potential was increased to 1.0 V. Thus, iron oxides form at lower potentials, while O2 gas formation occurs at a threshold potential. O2 formation may be enabled by the oxide layer passivating the iron against further oxidation. Results of ICP-MS of salt samples taken throughout the experiment showed no increase in Fe concentration in the salt. A metallic deposit formed on the outside of the cathode basket, implying some electrotransport occurred from the anode to the cathode. The results of this study show that cheap, disposable iron anodes are promising for the DER process. After an initial stage of formation of an iron oxide phase on the surface of the anode, O2 gas forms at a sufficiently high potential (1.0 V versus Ni/NiO). Further work is needed to achieve a more detailed mechanistic understanding of the effect of anode potential on specific reactions at the anode. Optimization of the anode potential may serve to promote O2 formation and minimize the rate of consumption of iron anodes. DISCLAIMER This work of authorship and those incorporated herein were prepared by Consolidated Nuclear Security, LLC (CNS) as accounts of work sponsored by an agency of the United States Government under Contract DE-NA-0001942. Neither the United States Government nor any agency thereof, nor CNS, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility to any non-governmental recipient hereof for the accuracy, completeness, use made, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency or contractor thereof, or by CNS. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency or contractor (other than the authors) thereof. COPYRIGHT NOTICE This document has been authored by Consolidated Nuclear Security, LLC, under Contract DE-NA-0001942 with the U.S. Department of Energy/National Nuclear Security Administration, or a subcontractor thereof. The United States Government retains and the publisher, by accepting the document for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this document, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, or allow others to do so, for United States Government purposes.
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Kim, Hyun-Jun, and Han-Cheol Choe. "Nanotube Morphology Changes on the Ti–xNb–Ag–Pt Alloy with Nb Contents." Journal of Nanoscience and Nanotechnology 20, no. 9 (2020): 5751–54. http://dx.doi.org/10.1166/jnn.2020.17663.
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The purpose of this study was to investigate the nanotube morphology changes of Ti–xNb–Ag–Pt alloys with Nb content. Ti–xNb–Ag–Pt was fabricated using arc melting vacuum furnace. The Ti– xNb–Ag–Pt ingot was further homogenized in an Ar atmosphere at 1100 °C for 1 h in a vacuum and then quenched at 0 °C. Nanotube formation on the samples was performed using anodization method with a DC power supply at 30 V for 2 h in 1 M H3PO4 +0.8 wt.% NaF at 25 °C. The surface morphology was observed using OM, FE-SEM, EDS, and XRD. In the microstructure of Ti–xNb–Ag–Pt alloy, needle-like structures on α and α″ gradually disappeared with increasing Nb, β-phase equilibrium structure appeared, and particle size decreased. The nanotube morphology of the Ti–xNb–Ag–Pt alloy changed according to the content of Nb. As the Nb content increases, the highly ordered nanotubes have changed to irregular nanotubes. The difference in dissolution area at the bottom of the nanotube was depending on the Nb content.
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Chida, Yoshihiro, Takeru Tomimori, Tomoaki Ebata, et al. "Oxygen Reduction Reaction of Pt and Non-PGM Transition Metal High Entropy Alloys Single Crystal Stacking Structures." ECS Meeting Abstracts MA2022-02, no. 42 (2022): 1552. http://dx.doi.org/10.1149/ma2022-02421552mtgabs.
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Introduction Nanoparticles of Pt as well as Pt-based alloys are widely used as cathode catalyst materials for proton exchange membrane fuel cells (PEMFC). However, electrochemical stability of the materials is rather low under practical operating conditions of PEMFC cathode, resulting in severe deactivation of oxygen reduction reaction (ORR). Therefore, further material’s developments are required for next-generation PEMFC cathode catalysts, i.e., more enhanced ORR durability with low platinum group metal (PGM) usage. High entropy alloys (HEAs), defined as single phase solid solutions of five or more elements in equal composition ratios, are known as thermodynamically stable, in comparison to conventional binary alloys. Furthermore, complex atomic-level local structures bring about unique electronic as well as (electro-)chemical properties that originating from lattice strains induced by specific local structures and/or so-called sluggish diffusion of the constituent elements. [1] However, to our best knowledge, no study has been made for ORR properties of Pt alloying with non-PGM Cantor alloy (fcc structure HEA with equi-atomic ratio of Cr-Mn-Fe-Co-Ni [2]) elements in strong acid condition. In this study, we synthesized lattice stacking structures of Pt/HEA(hkl) (hkl = (111), (110), (100)) through arc-plasma deposition (APD) of the Cantor alloy layer on Pt(hkl) substrate surfaces, followed by deposition of the surface Pt layer in ~10-7 Pa. Then, we performed cross-sectional STEM-EDS observations for Pt/HEA/Pt(hkl) stacking structures with atomic-level resolution and evaluated the ORR properties (initial activity and structural stability). Experimental An APD target of Cr-Mn-Fe-Co-Ni (Cantor alloy) was fabricated by sintering of equal quantity corresponding elements. 10 ML(monolayer)-thick (1 ML = ca. 0.3 nm) Cantor alloy layer (as HEA) was vacuum-deposited by APD on surface cleaned Pt(hkl) substrate surfaces at 300 K, and subsequently annealed in vacuum at 773 K for 30 minutes. Then, 4ML-thick Pt layer was deposited on the pre-deposited Cantor alloy layer at 300 K and annealed at 623 K. The samples thus prepared are designated as Pt/HEA/Pt(hkl). The atomic-level micro-structures and chemical bonding states of Pt/HEA/Pt(hkl) surfaces were characterized by cross-sectional STEM-EDS, RHEED, XPS etc. CV and LSV with the RDE method were conducted in N2-purged and O2-saturated 0.1 M HClO4. ORR activity was evaluated from j k values at 0.9 V vs. RHE by using Koutecky-Levich equation and structural stability (ORR durability) was discussed based upon activity transitions during applying the potential cycles (PCs) of 0.6(3s)‐1.0(3s) V vs. RHE in O2 saturated 0.1 M HClO4 at room temperature. Results and Discussion Atomically-resolved, cross-sectional HAADF-STEM images for Pt/HEA/Pt(hkl) (a) and EDS line profiles of elemental distributions at corresponding yellow arrows (b) are presented in Figure 1. As clearly shown in (a), irrespective of the Pt surface indices, (hkl), HEA (Cantor alloy) and surface Pt layers are epitaxially grown on the substrates. By contrast, elemental distributions in each surface normal (b) seriously depend on the substrate Pt lattice indices. Notably, severe thermal diffusion of the constituent elements including Pt is confirmed by (a) and (b) for both Pt/HEA/Pt(110) and (100). Figure 2 summarizes electrochemical results. 4ML-thick-Pt/10ML-thick-Co/Pt(hkl) that prepared under the same preparation condition of Pt/HEA/Pt(hkl), and clean Pt(hkl) (light blue and gray, respectively) are also shown as references. As shown in the figure, the Pt/HEA and Pt/Co fabricated on Pt(111) substrate (top) show quite similar CV characteristics (shrink in hydrogen adsorption charges (0 – 0.3 V) and higher potential shifts in oxygen-related species adsorption (0.6 – 1.0 V)), in comparison to clean Pt(111), and almost the same initial ORR activity. Meanwhile, the Pt/HEA fabricated on Pt(110) and (100) substrates show more reduced hydrogen absorption charges, compared with corresponding Pt/Co samples. Particularly, distinctive redox features for clean Pt(110) at 0.12 V and for Pt(100) at 0.35 V are absent for corresponding CVs, suggesting specific topmost surface atomic-structures might be formed in the electrolyte, that probably resulting from significant electronic interactions between surface Pt and HEA constituent elements (Cr, Mn, Fe, Co, Ni) and/or local strain of the surface Pt layer induced by distorted Pt-HEA lattices located nearby. One might notice that Pt/HEA/Pt(110) reveals remarkable ORR activity enhancement compared with corresponding Pt/Co/Pt(110), while the activities for Pt/HEA and corresponding Pt/Co surfaces fabricated on Pt(100) are almost the same value. At the meeting, correlations between surface atomic-level micro-structures of Pt/HEA/Pt(hkl) and ORR properties will be discussed in detail. Acknowledgement This study was supported by new energy and industrial technology development organization (NEDO) of Japan and JST SPRING, Grant Number JPMJJSP2114. Reference [1] J. Yeh, JOM, 65, 1759 (2013). [2] B. Cantor et al., Mater. Sci. Eng. A, 375, 213 (2004). Figure 1
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Barkov, Andrei Y., Nadezhda D. Tolstykh, Nobumichi Tamura, Robert F. Martin, Andrew M. McDonald, and Louis J. Cabri. "Ferrotorryweiserite, Rh5Fe10S16, a New Mineral Species from the Sisim Placer Zone, Eastern Sayans, Russia, and the Torryweiserite–Ferrotorryweiserite Series." Minerals 11, no. 12 (2021): 1420. http://dx.doi.org/10.3390/min11121420.
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Ferrotorryweiserite, Rh5Fe10S16, occurs as small grains (≤20 µm) among droplet-like inclusions (up to 50 μm in diameter) of platinum-group minerals (PGM), in association with oberthürite or Rh-bearing pentlandite, laurite, and a Pt-Pd-Fe alloy (likely isoferroplatinum and Fe-Pd-enriched platinum), hosted by placer grains of Os-Ir alloy (≤0.5 mm) in the River Ko deposit. The latter is a part of the Sisim placer zone, which is likely derived from ultramafic units of the Lysanskiy layered complex, southern Krasnoyarskiy kray, Russia. The mineral is opaque, gray to brownish gray in reflected light, very weakly bireflectant, not pleochroic to weakly pleochroic (grayish to light brown tints), and weakly anisotropic. The calculated density is 5.93 g·cm–3. Mean results (and ranges) of four WDS analyses are: Ir 18.68 (15.55–21.96), Rh 18.34 (16.32–20.32), Pt 0.64 (0.19–1.14), Ru 0.03 (0.00–0.13), Os 0.07 (0.02–0.17), Fe 14.14 (13.63–14.64), Ni 13.63 (12.58–14.66), Cu 4.97 (3.42–6.41), Co 0.09 (0.07–0.11), S 29.06 (28.48–29.44), and total 99.66 wt.%. They correspond to the following formula calculated for a total of 31 atoms per formula unit: (Rh3.16Ir1.72Pt0.06Ru0.01Os0.01)Σ4.95(Fe4.48Ni4.11Cu1.38Co0.03)Σ10.00S16.05. The results of synchrotron micro-Laue diffraction studies indicate that ferrotorryweiserite is trigonal; its probable space group is R3¯m (#166) based on its Ni-analog, torryweiserite. The unit-cell parameters refined from 177 reflections are a = 7.069 (2) Å, c = 34.286 (11) Å, V = 1484 (1) Å3, and Z = 3. The c:a ratio is 4.8502. The strongest eight peaks in the X-ray diffraction pattern derived from results of micro-Laue diffraction study [d in Å(hkil)(I)] are 2.7950 (202¯5) (100); 5.7143 (0006) (60); 1.7671 (224¯0) (44.4); 3.0486 (202¯1) (39.4); 5.7650 (101¯2) (38.6); 2.5956 (202¯7) (37.8); 3.0058 (112¯6) (36.5); and 1.5029 (42¯ 2¯12) (35.3). Ferrotorryweiserite and the associated PGM crystallized from microvolumes of residual melt at late stages of crystallization of grains of Os- and Ir-dominant alloys occurred in lode zones of chromitites of the Lysanskiy layered complex. In a particular case, the residual melt is disposed peripherally around a core containing a disequilibrium association of magnesian olivine (Fo72.9–75.6) and albite (Ab81.6–86.4), with the development of skeletal crystals of titaniferous augite: Wo40.8–43.2En26.5–29.3Fs20.3–22.6Aeg6.9–9.5 (2.82–3.12 wt.% TiO2). Ferrotorryweiserite represents the Fe-dominant analog of torryweiserite. We also report occurrences of ferrotorryweiserite in the Marathon deposit, Coldwell Complex, Ontario, Canada, and infer the existence of the torryweiserite–ferrotorryweiserite solid solution in other deposits and complexes.
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Schonvogel, Dana, Nambi Krishnan Nagappan, Nina Bengen, Julia Müller-Hülstede, and Peter Wagner. "Investigation of Pt/Fe-N-C Hybrids Towards ORR in Acidic Environment." ECS Meeting Abstracts MA2022-02, no. 42 (2022): 1580. http://dx.doi.org/10.1149/ma2022-02421580mtgabs.
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Polymer electrolyte membrane fuel cells (PEMFCs) are recognized as one of the renewable energy sources in portable, automobile, and stationary applications. Currently, both low temperature (LT) and high temperature (HT) PEMFCs use platinum group metal (PGM) based catalysts for oxygen reduction reaction (ORR) containing usually Pt nanoparticles on carbon black. To reduce the total cost of PEMFC stack, worldwide researchers have considerable attention to find an inexpensive alternative catalyst. Recently, metal-nitrogen-carbon (M-N-C) compounds such as Fe-N-Cs are the most promising PGM-free catalysts for ORR. However, they suffer from insufficient volumetric activity and electrochemical stability in PEMFCs. [1,2] Xiao et al. have proven an improved electrochemical stability of Pt-Fe-N-C electrocatalysts consisting of atomically dispersed Pt and Fe atoms or Pt-Fe alloy nanoparticles in comparison with Fe-N-C only. [3] Mechler et al. have reported that the addition of 1-2 wt.% Pt in hybrid Pt/Fe-N-C catalyst performs well with an increased stability in LT-PEMFCs. [4] Liao et al. have recently shown better ORR activity of Pt/Fe-N-C than Pt/C. [5] With the overriding goal of reducing LT- and HT-PEMFC production costs, Pt/Fe-N-C activity, selectivity and stability with systematically reducing the Pt-content has not been investigated yet. In this study, Pt/Fe-N-C hybrids are synthesized using PMF-011904 from Pajarito Powder (USA) as catalyst support and wet-chemically precipitated Pt nanoparticles with targeted Pt-contents of 40, 5, 1 and 0 wt.%. First, ICP mass spectrometry is used for Pt quantification along all catalysts, and transmission electron microscopy is carried out to investigate morphology and Pt nanoparticle diameter and distribution on the Fe-N-C catalyst. Second, ORR activity and selectivity is investigated by rotating ring disc electrode (RRDE) experiments in 0.1 mol L-1 HClO4, and electrochemical surface area of Pt is calculated by hydrogen underpotential deposition and CO stripping voltammetry. Last, accelerated stress testing (AST) is performed with 5,000 triangle potential cycles between 0.6–1.5 VRHE to evaluate the catalyst stability. Figure 1 shows the initial ORR curves during the RRDE experiments. The mass activities of 40, 5 and 1 wt.% Pt/Fe-N-C determined at 0.9 VRHE are 222.5 ± 41.2 A gPt -1, 170.8 ± 80.4 A gPt -1 and 49.0 ± 8.6 A gPt -1, respectively. Thus, the mass activity depends on Pt-content in the hybrid catalyst strongly. In addition, the other electrochemical characterization results are also going to be discussed in terms of catalyst selectivity, stability and the correlation with morphological aspects during the presentation. Figure 1 ORR curves in O2-saturated 0.1 mol L-1 HClO4 electrolyte with rotation speed of 1,600 rpm and scan rate of 5 mV s-1 (averaged results of three separate electrodes per each catalyst). [1] Y. He, S. Liu, C. Priest, Q.Shi , G. Wu, Chem. Soc. Rev. 2020, 11, 3484–3524. [2] T. Reshetenko, A. Serov, M. Odgaard, G. Randolf, L. Osmieri, A. Kulikovsky, Electrochem. Commun. 2020, 118, 106795. [3] F. Xiao, G.-L. Xu, C.-J. Sun, I. Hwang, M. Xu, H.-W. Wu, Z. Wei, X. Pan, K. Amine, M. Shao, Nano Energy 2020, 77, 10592. [4] A. K. Mechler, N. R. Sahraie, V. Armel, A. Zitolo, M. T. Sougrati, J. N. Schwämmlein, D. J. Jones, F. Jaouen, J. Electrochem. Soc. 2018, 165, F1084. [5] W. Liao, S. Zhou, Z. Wang, F. Liu, H. Pan, T. Xie, Q. Wang, ChemCatChem 2021, 13, 23, 4925-4930. Figure 1
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Ansari, Haris Masood, Sara Bouzidi, Adam Bass та Viola Ingrid Birss. "Transition Metal Doping of La0.3Ca0.7Fe0.7Cr0.3O3-δ for Nanoparticle-Enhanced Reversible CO2-CO Electrocatalysis". ECS Meeting Abstracts MA2022-01, № 39 (2022): 1774. http://dx.doi.org/10.1149/ma2022-01391774mtgabs.
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Fluctuations in supply and demand result in wasted energy during off-peak electric grid hours, with Reversible Solid Oxide Cells (RSOCs) potentially providing an efficient means by which such energy can be stored to create a highly sustainable grid.1 A RSOC can catalyze reactions such as the CO2 Reduction Reaction (CO2RR) by operating in the Solid Oxide Electrolysis Cell (SOEC) mode when energy supply is high, or in the Solid Oxide Fuel Cell (SOFC) mode when demand is high while oxidizing CO.1 The estimated yearly energy storage requirement is about 2-3 months per year, with RSOCs capable of achieving this goal.1 Single phase perovskite materials with the composition La0.3M0.7Fe0.7Cr0.3O3-δ (M = Sr, Ca) (LMFCr) have emerged as promising electrocatalysts for both fuel and oxygen electrodes in symmetrical RSOCs due to their phase stability in air and fuels (pO2 ~ 0.21 – 10-21 atm) and their compatibility with doped ceria-buffered yttria- and scandia-stabilized zirconia (YSZ/SSZ) electrolytes.2,3 The Ca analogue of LMFCr (LCFCr) has generally shown better performance and compatibility with other cell components,3 with significant efforts directed towards further enhancing its CO2RR activity by employing various approaches, including nanoscale modifications.4 One such technique is nanoparticle (NP) exsolution, which can greatly increase the catalytic surface area.5 This method employs B-site doping with Ni or Co followed by exposure to reducing conditions to decorate the catalyst surface with B-site metal alloy NPs.4 These are strongly anchored to the bulk material, highly resistant to coking, and stable under the harsh conditions of RSOCs.4 In our initial work, the exsolution characteristics of Fe-Ni NPs from 5% Ni-doped LCFCr (LCFCrN) were studied in H2:N2 and CO2:CO atmospheres using ex situ XRD, SEM, and STEM-EDS.4 Exsolution kinetics were rapid in H2:N2 (pO2 ~ 10-23 atm) at 800 °C with NPs assuming an average size of 45 nm and an Fe-rich Fe0.64Ni0.36 composition within 1 h exposure to 5H2:95N2. On the other hand, 70CO:30CO2 atmospheres (pO2 ~ 10-20 atm) gave sluggish kinetics with the NPs achieving an average size of 40 nm and a Ni-rich FeNi3 composition even after more than 25 hours of treatment. This suggests stability to coarsening in highly reducing atmospheres.4 In more recent work, 5% Co-doped LCFCr (LCFCrCo) perovskites show visible Fe-Co NP formation at 800 °C upon exposure to 5H2:95N2 for at least 1 h or to 70CO:30CO2 for at least 5 h. Electrochemical characterization of Fe-Ni NP decorated LCFCrN (Fe-Ni@LCFCrN) was conducted on 2.5 cm diameter cells using ceria-buffered SSZ electrolyte. A LCFCrN ink was screen-printed onto a ~0.5 cm2 area on both sides of the cell followed by sintering at 1100 °C for 2 h. Au was painted onto each electrode, and the cell was sintered again at 825 °C for 1 h. Electrical connections were made via Au gauzes and wires. NP exsolution was induced by exposing the fuel electrode to 5H2:95N2 for 2 h at 800 °C. Various CO2:CO mixtures (100:0, 90:10, 70:30, 50:50) were supplied to the fuel electrode while air was supplied to the oxygen electrode with flow rates of 50 mL/min. Electrochemical performance was tested via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. CVs showed that the NPs enhanced LCFCrN activity for CO2RR (~ 15%) and more notably for CO oxidation (~ 75%) at the same overpotential (~ 0.7 V), making the catalyst equally active for the two reactions. 15-minute potentiostatic tests indicated stable current densities of about –0.65, –0.634, and –0.618 A/cm2 in 100% CO2, 90CO2:10CO, and 70CO2:30CO respectively at a cell potential of 1.6 V. Medium-term (10 h) potentiostatic tests for CO2RR indicated excellent stability with a current density of –0.28 A/cm2 at a cell potential of 1.3 V in 70CO2:30CO (pO2 ~ 10-18 atm). The excellent electrochemical performance in both the SOFC and SOEC modes makes Fe-Ni@LCFCrN a very promising electrode material for RSOCs. Further work on LCFCrCo is underway, with comparisons being made between LCFCrN and LCFCrCo on CO2-CO electrocatalysis and NP characteristics. References Jensen, S. H.; Graves, C.; Mogensen, M.; Wendel, C.; Braun, R.; Hughes, G.; Gao, Z.; Barnett, S. A. Energy Environ. Sci. 8, 2471 (2015). Molero-Sánchez, B.; Addo, P.; Buyukaksoy, A.; Paulson, S.; Birss, V. I. Faraday Discuss. 182, 159 (2015). Molero-Sánchez, B.; Prado-Gonjal, J.; Avila-Brande, D.; Chen, M.; Moran, E.; Birss, V. I. J. Hydrog. Energy. 40, 1902 (2015). Ansari, H. M.; Bass, A. S.; Ahmad, N.; Birss, V. I. Mater. Chem. A (2022). Zhu, Y.; Dai, J.; Zhou, W.; Zhong, Y.; Wang, H.; Shao, Z. Mater. Chem. A. 6, 13582 (2018).
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Barkov, A. Y., N. D. Tolstykh, R. F. Martin, N. Tamura, Chi Ma, and A. A. Nikiforov. "Kuvaevite, Ir5Ni10S16, a New Mineral Species, Its Associations and Genetic Features, from the Sisim River Placer Zone, Eastern Sayans." Russian Geology and Geophysics 63, no. 12 (2022): 1373–87. http://dx.doi.org/10.2113/rgg20224455.
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Abstract —Kuvaevite, ((Ir,Rh)5(Ni,Fe,Cu)10S16), forms small grains (up to 20 µm across) in globular inclusions hosted by grains of Os–Ir–(Ru) alloys (up to 0.5 mm) in ore occurrences along the Ko River in the Sisim placer zone, Eastern Sayans. Rh-bearing pentlandite or oberthürite (or both), the minerals of the laurite-erlichmanite series and Pt–(Pd)–Fe alloys are the main associated minerals. Kuvaevite is gray to brownish gray in color in reflected light. Its bireflectance is weak to absent. It is slightly pleochroic in gray to light brown shades, and slightly anisotropic, from gray to light yellow shades. Its calculated density is 6.37 g/cm3. According to results of microprobe analyses (n = 3) carried out using wavelength-dispersive spectrometry, WDS, the composition of kuvaevite is: Cu 5.94 (4.39–6.89), Ni 13.95 (13.80–14.24), Fe 10.95 (10.18–11.97), Co 0.07 (0.06–0.10), Ir 32.38 (32.19–32.73), Rh 7.27 (7.22–7.31), Pt 1.91 (1.67–2.06), Os 0.05 (0–0.09), Ru 0.05 (0.04–0.05), S 27.06 (26.77–27.41), total 99.63 wt.%. The empirical formulae calculated using the mean results of analyses are: (Ir3.22Rh1.35Pt0.19Ru0.01Os0.01)Σ4.78(Ni4.54Fe3.75Cu1.79Co0.02)Σ10.10S16.13 (WDS) and (Ir3.23Rh1.43Pt0.25)Σ4.91(Ni4.49Fe3.57Cu1.86Co0.06)Σ9.98S16.11 (SEM/EDS; n = 56). These are based on a total of 31 atoms according to structural data obtained for torryweiserite, the rhodium-dominant analogue. Kuvaevite forms solid-solution series with torryweiserite, tamuraite and ferrotorryweiserite, all these being isostructural. The symmetry of kuvaevite was determined using the synchrotron Laue microdiffraction; the results are in good agreement with the trigonal crystal system and give the following unit-cell parameters: a = 7.079(5) Å, c = 34.344(12) Å, V = 1490(2) Å3; Z = 3. The ratio c/a is 4.852. The probable space-group, R3m (#166), is based on structural results for torryweiserite. The strongest eight reflections in the X-ray diffraction pattern derived from the microdiffraction study [d in Å(hkl) (I)], are the following: 3.0530(201)(43), 3.0103(216)(100), 2.9962(1010)(53), 2.7991(205)(50), 2.4946(208)(31), 1.9208(3110)(41), 1.7697(410)(73), 1.7582(2016)(66). The results of the electron backscatter diffraction study (EBSD) of two kuvaevite crystals are well–indexed based on the R3m space group. Kuvaevite and related sulfides significantly vary in composition in the Ko River placer, in the entire Sisim zone, and in some other ore occurrences worldwide. Associations of platinum-group minerals observed in ore occurrences at Ko River and in the Sisim zone seem to be genetically related to bedrock zones of chromite-bearing ultramafic rocks (serpentinites) of the Lysanskiy complex. Kuvaevite and other minerals present in the polymineralic inclusions, hosted by Os–Ir–(Ru) alloys, formed from droplets of residual melt. This melt accumulated the “incompatible” elements, which could not be incorporated into the structure of the host alloy, including lithophile elements, chalcogens (S, Te), semimetals (As, Sb, Bi), base metals (Fe, Ni, Cu), as well as relatively low-temperature PGE species (Pt, Pd) and Rh. There are local data on metastable crystallization and undercooling of the silicate melt, as well as effective differentiation and fractionation of S and ore components during the crystallization of these inclusions. Kuvaevite is named after O.M. Kuvaev (1934–1975), a prominent geologist, geophysicist and writer.
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Bi, Wei, Elod L. Gyenge, and David P. Wilkinson. "Lithium-Mediated Nitrogen Reduction in a Flow Electrolyzer Cell Using Gas Diffusion Electrodes with Carbon-Based Electrocatalysts." ECS Meeting Abstracts MA2024-01, no. 39 (2024): 2310. http://dx.doi.org/10.1149/ma2024-01392310mtgabs.
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Due to the sluggish kinetics in activating the chemically stable dinitrogen (N2) and the competing hydrogen evolution reaction in aqueous media, recent attention in the field of direct ammonia (NH3) electrosynthesis has been increasingly drawn to the lithium-mediated N2 reduction reaction (LNRR) in tetrahydrofuran (THF)-based non-aqueous electrolyte. In particular, near 100% faradaic efficiency (FE) and/or a current density (j) of 100 mA cm-2 has been demonstrated with unique electrolyte (proton-shuttle additive) and/or electrode designs (expansive electrochemical surface area) in single-compartment cells at elevated N2 pressure (5 – 20 bar).[1,2] A submerged electrode leads to electrolyte flooding and restricts to N2 mass transfer to the electrode surface where electrodeposited Li as an electron mediator is available.[3] However, flow cell electrolyzers containing gas-diffusion electrodes can improve this technology to practical relevance, which features the LNRR on the cathode and hydrogen oxidation reaction (HOR) on the anode. Differing from single-compartment cells, the HOR supplements the ethanol additive (<1 vol%) as the proton source, which not only prevents the oxidative electrolyte degradation but also reduces the energy consumption due to a lower equilibrium anode potential (E0 = 0 VRHE). Gas-diffusion electrodes (GDEs) are used in the few LNRR studies with flow cell configurations, which are prepared by electro- or electroless depositing electrocatalysts (e.g., Pt [4] or PtAu alloy [5]) onto a porous substrate. In this work, carbon-based electrocatalysts (Vulcan XC72R carbon black, battery-grade conductive carbon SUPER C45, and graphitic carbon SFG6L) as low-cost alternatives to previously studied precious metals are assessed for their LNRR performance in flow cells using an HOR anode. In comparison to Vulcan-supported Pt, XC72R and C45 can obtain similar NH3 production rates (rNH3 )and FE at the same . Continuous LNRR at -3 mA cm-2 was demonstrated with linearly increased NH3 production for over 8 h without catalyst layer detachment, which was also verified with open circuit and Ar control experiments (Fig. 1). By presenting the LNRR activity with GDEs spray-coated with carbon-based electrocatalysts, opportunities for future research are suggested, such as novel carbon materials and porous substrates other than SSC for facile N2 mass transfer and Li deposition. References [1] H.L. Du, M. Chatti, R.Y. Hodgetts, P. V. Cherepanov, C.K. Nguyen, K. Matuszek, D.R. MacFarlane, A.N. Simonov, Electroreduction of nitrogen with almost 100% current-to-ammonia efficiency, Nature. 609 (2022) 722–727. https://doi.org/10.1038/s41586-022-05108-y. [2] K. Li, S.G. Shapel, D. Hochfilzer, J.B. Pedersen, K. Krempl, S.Z. Andersen, R. Sažinas, M. Saccoccio, S. Li, D. Chakraborty, J. Kibsgaard, P.C.K. Vesborg, J.K. Nørskov, I. Chorkendorff, Increasing Current Density of Li-Mediated Ammonia Synthesis with High Surface Area Copper Electrodes, ACS Energy Lett. 7 (2022) 36–41. https://doi.org/10.1021/acsenergylett.1c02104. [3] S.Z. Andersen, M.J. Statt, V.J. Bukas, S.G. Shapel, J.B. Pedersen, K. Krempl, M. Saccoccio, D. Chakraborty, J. Kibsgaard, P.C.K. Vesborg, J. Nørskov, I. Chorkendorff, Increasing stability, efficiency, and fundamental understanding of lithium-mediated electrochemical nitrogen reduction, Energy Environ. Sci. 13 (2020) 4291–4300. https://doi.org/10.1039/D0EE02246B. [4] N. Lazouski, K.J. Steinberg, M.L. Gala, D. Krishnamurthy, V. Viswanathan, K. Manthiram, Proton Donors Induce a Differential Transport Effect for Selectivity toward Ammonia in Lithium-Mediated Nitrogen Reduction, ACS Catal. 0 (2022) 5197–5208. https://doi.org/10.1021/acscatal.2c00389. [5] X. Fu, J.B. Pedersen, Y. Zhou, M. Saccoccio, S. Li, R. Sažinas, K. Li, S.Z. Andersen, A. Xu, N.H. Deissler, J.B.V. Mygind, C. Wei, J. Kibsgaard, P.C.K. Vesborg, J.K. Nørskov, I. Chorkendorff, Continuous-flow electrosynthesis of ammonia by nitrogen reduction and hydrogen oxidation, Science (80-. ). 379 (2023) 707–712. https://doi.org/10.1126/science.adf4403. Figure 1
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Zhu, Xiaoou, Yu Li, Xueting Chen, Guili Yin, Yining Chen, and Chenxu Xiao. "Microstructure and mechanical properties of CP780 steel - 7075 aluminum alloy laser welded joint assisted by rotating magnetic field." Materials Research Express, October 14, 2024. http://dx.doi.org/10.1088/2053-1591/ad86ae.
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Abstract This study uses a rotating magnetic field for laser welding on 1 mm thick CP780 high-strength steel and 1.5 mm thick 7075 aluminum alloy. The effects of different welding parameters (B = 0 mT, B = 65 mT with V = 0°/s, B = 65 mT with V = 10°/s) on the morphology, microstructure, and tensile properties of welded joints are analyzed. At B = 0 mT, the weld shape is V-shaped, with the intermetallic compounds primarily consisting of needle-like brittle Al-rich (Fe, Si)Al2 phase and fewer granular ductile Fe-rich (Fe, Si)Al phase, resulting in poor mechanical properties. With the application of the rotating magnetic field, the laser energy becomes more concentrated, forming a "T" shape weld. The rotating magnetic field (B = 65 mT with V = 10°/s) generates a constantly changing Lorentz force, promoting molten pool flow and enhancing Fe diffusion within the weld. This process reduces needle-like brittle Al-rich (Fe, Si)Al2 phase and increases granular ductile Fe-rich (Fe, Si)Al phase. It also accelerates the weld cooling rate and inhibits the reaction time and grain growth of intermetallic compounds, thereby reducing the thickness and content of the intermediate transition layer and significantly improving mechanical properties. A comprehensive comparison shows that the best mechanical properties are achieved at B = 65 mT with V = 10°/s. This study offers new insights and a theoretical foundation for achieving cost-effective, high-performance welded joints in advanced high-strength steel and high-strength aluminum alloy for automobiles, thereby facilitating lightweight vehicle development.
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Tan, Hui, Shuai Wang, Jun Cheng, Shengyu Zhu, and Jun Yang. "Sliding Tribological Behavior of Al–Fe–V–Si–Graphite Solid-Lubricating Composites at Elevated Temperatures." Journal of Tribology 140, no. 1 (2017). http://dx.doi.org/10.1115/1.4037213.
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Aluminum alloy metal matrix composites (Al-MMCs) have been considered as promising materials for aerospace and automotive industries due to their excellent balance of physical, mechanical, and tribological properties. In the present work, the Al–Fe–V–Si alloy matrix composites with 0–20 wt. % copper-coated graphite were fabricated by hot-pressed sintering. The dry sliding tests were carried out at various temperatures ranging from room temperature (RT) to 350 °C. The microstructure, phase, hardness, and worn surface of the sintered composites were examined in detail. The effect of copper-coated graphite amount on the properties of the composite was also investigated. The results show that the Al–Fe–V–Si–graphite composites mainly consist of α-Al, Al8Fe2Si intermetallic, and graphite phases. The addition of Cu-coated graphite can decrease the friction coefficient and wear rate from RT to 350 °C. The Al–Fe–V–Si–graphite composite containing 10 wt. % copper-coated graphite exhibits better wear properties than other composites. The favorable lubricating properties were attributed to the tribolayer with graphite lubricating film formed on the worn surface.
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Belevskii, Stanislav, Serghei Silkin, Natalia Tsyntsaru, Henrikas Cesiulis, and Alexandr Dikusar. "The Influence of Sodium Tungstate Concentration on the Electrode Reactions at Iron–Tungsten Alloy Electrodeposition." August 23, 2021. https://doi.org/10.5281/zenodo.5235331.
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The investigation of Fe-W alloys is growing in comparison to other W alloys with iron group metals due to the environmental and health issues linked to Ni and Co materials. The influence of Na<sub>2</sub>WO<sub>4</sub> concentration in the range 0 to 0.5 M on bath chemistry and electrode reactions on Pt in Fe-W alloys’ electrodeposition from citrate electrolyte was investigated by means of rotating disk electrode (RDE) and cyclic voltammetry (CV) synchronized with electrochemical quartz crystal microbalance (EQCM). Depending on species distribution, the formation of Fe-W alloys becomes thermodynamically possible at potentials less than −0.87 V to −0.82 V (vs. Ag/AgCl). The decrease in electrode mass during cathodic current pass in the course of CV recording was detected by EQCM and explained. The overall electrode process involving Fe-W alloy formation may be described using formalities of mixed kinetics. The apparent values of kinetic and diffusion currents linearly depend on the concentration of Na<sub>2</sub>WO<sub>4</sub>. Based on the values of partial currents for Fe and W, it was concluded that codeposition of Fe-W alloy is occurring due to an autocatalytic reaction, likely via the formation of mixed adsorbed species containing Fe and W compounds or nucleation clusters containing both metals on the electrode surface
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Jain, Sandeep, Naveen L, Vinod Kumar, and Sumanta Samal. "Solidification Simulation and Experimental Validation of Single-Phase Fe–Co–Cr–Ni–V–Al High-Entropy Alloy." Transactions of the Indian Institute of Metals, February 8, 2023. http://dx.doi.org/10.1007/s12666-022-02821-0.
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Yu, Yutong, Lisheng Zhong, Enci Han, et al. "First-principles study of the matrix alloying effect of X (X = Cr, Mo, W, V, Ti, Si) on the bonding characteristics and mechanical properties of the NbC/Fe interface." Journal of Materials Science: Materials in Engineering 20, no. 1 (2025). https://doi.org/10.1186/s40712-024-00206-3.
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Abstract Matrix alloying is currently the most commonly used means to improve the interfacial bonding strength. To explore the influence of different alloying elements on the interfacial bonding characteristics and mechanical properties of NbC/Fe, this study investigates the influence of the alloying element X (X = Cr, Mo, W, V, Ti, Si) on the properties of the NbC/Fe surface by using first principles and analyzes the segregation behavior, work of adhesion, electronic structure, and tensile strength of the interface before and after doping with the aforementioned alloying elements. The results demonstrate that the segregation energies of Cr, V, and Ti are less than 0, indicating that these alloy elements tend to segregate at the interface. Other alloying elements have positive segregation energies and are solids dissolved in the Fe matrix. When Si is doped at the interface, the adhesion work of the interface is reduced, and the binding property of the interface is destroyed. The charge density difference and population analyses demonstrated that the charge transfer between Cr, V, Ti, Mo, and W was localized, and there was a charge depletion region, presenting covalent characteristics. After doping, the Si atom demonstrated a charge state of loss, and the charge transfer had no clear direction, indicating the characteristics of an ionic bond. According to the theoretical tensile strength analysis, the addition of Mo, W, Si, and Cu will destroy the critical tensile strain at the interface. The tensile strength and strain of the interface significantly improved after the matrix alloying of Fe by Cr, V and Ti, the microstructure evolved during the tensile deformation, and a new phase was formed. A correlation between the atomic calculations and mechanical properties can be determined using first principles, as well as a reference for practical engineering applications.
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Yuan, Jiaxin, Xiaodi Cheng, Hanqing Wang, et al. "A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities." Nano-Micro Letters 12, no. 1 (2020). http://dx.doi.org/10.1007/s40820-020-00442-0.
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AbstractCost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction (OER) are critical to the energy crisis and environmental pollution. Herein, we report a superaerophobic three dimensional (3D) heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy (NiSe2/NiFe2Se4@NiFe) prepared by a thermal selenization procedure. In this unique 3D heterostructure, numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~ 100 nm are grown on NiFe alloy in a uniform manner. Profiting by the large active surface area and high electronic conductivity, the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media, outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm−2, respectively, which is among the most active Ni/Fe-based selenides, and even superior to the benchmark Ir/C catalyst. The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.
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Zhang, Lingxi, and Min Chen. "Recovery of Valuable Metals and Production of Fe-V Crude Alloy from Vanadium-Enriched Slag Using Aluminum Dross as a Reductant." JOM, November 2, 2022. http://dx.doi.org/10.1007/s11837-022-05561-0.
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Knudsen, Ole Øystein, Eystein Vada, Waldemar Krieger, Jan Bertram, Ivana Jevremovic, and Håvard Wilson. "Cathodic protection of aluminium in seawater." Materials and Corrosion, March 26, 2024. http://dx.doi.org/10.1002/maco.202314229.
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AbstractCathodic protection of various 6000 aluminium alloys and variants of EN AW‐5083 in seawater has been studied. The alloys were immersed in seawater and polarized to about −1.06 V versus Ag/AgCl for 1 year. The cathodic current density increased initially due to formation of a copper film on the surface, but the effect was temporary. After 200 days, the current demand for cathodic protection had stabilized on all the investigated alloys at 0 to about 20 mA/m2, depending on the Fe/Si ratio in the alloy. Depending on the content of noble intermetallic particles, the aluminium will corrode at a low and constant rate. Application of a coating on the aluminium will decrease the cathodic current demand for cathodic protection significantly. Coatings on submerged aluminium are very stable and not susceptible to degradation mechanisms like cathodic disbonding.
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Khatkevich, V. M., S. O. Rogachev, S. A. Nikulin, and E. N. Tokmakova. "Structure and Mechanical Properties of a Layered Composite Based on Fe–Cr–V Alloy and High-Nitrogen High-Chromium Steel After Hot Pressing and Annealing." Metals and Materials International, March 8, 2021. http://dx.doi.org/10.1007/s12540-020-00941-0.
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Duncan, M. J., and L. F. Nazar. "Iron Oxides as Anodic Materials in Li Rechargeable Batteries." MRS Proceedings 548 (1998). http://dx.doi.org/10.1557/proc-548-71.
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ABSTRACTThe open framework material, CaFe204 and the isostructural solid solution phases, LiyCa1−(x+y)/2SnxFe2−xO4, where 0<y<x and O<x<0.6 have been evaluated as promising anodic materials in Li-ion batteries. These materials can be discharged to low potential, the end member CaFe2O4 attaining a discharge capacity of 800 mAh/g at a cutoff voltage of 50 mV. The capacity is enhanced on substitution of Fe3+, for Sn4+ in the framework (920 mAh/g for the composition, Li0.6Ca0.4Sn0.6Fe1.404). On introducing Sn into the structure the reversible capacity is also substantially increased compared with the parent material. Although there is a large irreversible component to the redox process during first discharge-charge, the materials can sustain a stable reversible capacity of >600 mAh/g within the voltage window of 3.0-0.005 V. The profile of the electronic density plots suggest there is no phase separation to Li/Sn alloy phases on reduction, but rather a lithium-rich, oxygen deficient Sn/Fe/oxide matrix is formed.
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Zayonchkovskiy, Vyacheslav S., Irina A. Antoshina, Kyaw Kyaw Aung, Evgenij I. Isaev та Igor’ M. Milyaev. "Рентгенодифракционное исследование тонких металлических пленок с магнитными слоями сплава Fe-Cr-Co". Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 22, № 1 (2020). http://dx.doi.org/10.17308/kcmf.2020.22/2529.
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Цель статьи – определение фазового состава структур пленочных постоянных магнитов со слоями сплава Fe-Cr-Co микронного диапазона толщин, называемого сплавом Kaneko. Знание фазового состава необходимо для разработки физико-технологических подходов создания оптимальных структур на подложках монокристаллического кремния с пленочным постоянным магнитом на основе дисперсионно-твердеющего сплава с вектором намагниченности в плоскости кремниевой подложки.Методом магнетронного напыления на кремниевой подложке были получены трехслойные металлические пленки: слой дисперсионно-твердеющего сплава на основе системы Fe-Cr-Co (толщиной 3600 нм), компенсационный медный слой (3800 нм) и ванадиевый адгезионно-барьерный слой (110 нм). Сформированные на кремниевой подложке многослойные пленки подвергались одноминутному отжигу в высоком вакууме в диапазоне температур 600–650 °С. Методом рентгеновской дифракции выполнен качественный фазовый анализ структур, полученныхмагнетронным напылением и подвергнутых одноступенчатой термической обработке.Определено, что в слое дисперсионно-твердеющего сплава на основе системы Fe-Cr-Co, полученного магнетронным напылением, не образуются окислы основных компонентов и s-фаза, как в процессе получения, так и после высоковакуумного «быстрого» одноминутного отжига в диапазоне температур 600–650 °С. При температуре отжига 630 °С наблюдается максимальная интенсивность рентгеновской линии (110) a-фазы, что свидетельствует о формировании преимущественно a-твердого раствора и является предпосылкой для корректного проведения последующих ступеней отжига для спинодального распада этой фазы.
 
 
 
 
 ЛИТЕРАТУРА
 
 Kaneko H., Homma M., Nakamura K. New ductile permanent magnet of Fe-Cr-Co system. AJP Conference Proceedings. 1972;5: 1088–1092. DOI: https://doi.org/10.1063/1.2953814
 Tsung-Shune Chin, Kou-Her Wang, Cheng-Hsiung Lin. High coercivity Fe-Cr-Co thin fi lms by vacuum evaporation. Japanese Journal of Applied Physics. 1991;30(8): 1652–1695. DOI: https://doi.org/10.1143/jjap.30.1692
 Chang H. C., Chang Y. H., Yao S. Y. The magnetic properties and microstructures of Fe-Cr-Co thin fi lms obtained by ion beam sputtering. Materials Science and Engineering B. 1996; 39(2): 87–94. DOI: https://doi.org/10.1016/0921-5107(95)01428-4
 Masahiro Kitada, Yoshihisa Kamo, Hideo Tanabe. Magnetoresistive thin-fi lm sensor with permanent magnet biasing film. Journal of Applied Physics. 1985;58(4): 1667–1670. DOI: https://doi.org/10.1063/1.336058
 Rastabi R. A., Ghasemi A., Tavoosi M., Ramazani M. Magnetic features of Fe-Cr-Co alloys with tailoring chromium content fabricated by spark plasma sintering. Magnetic Materials. 2017;426(15): 742–752. DOI: https://doi.org/10.1016/j.jmmm.2016.10.132
 Zubair Ahmad, Zhongwu Liu, A. ul Haq. Synthesis, magnetic and microstructural properties of Alnico magnets with additives. Journal of Magnetism and Magnetic Materials. 2017;428: 125–131. DOI: https://doi.org/10.1016/j.jmmm.2016.12.023
 Jin Y., Zhang W., Kharel P. R., Valloppilly S. R., Skomski R., Sellmyer D. J. Effect of boron doping on nanostructure and magnetism of rapidly quenched Zr2Co11-based alloys. AIP Adv. 2016;6(5): 056002. DOI: https://doi.org/https://doi.org/10.1063/1.4942556
 Lin Zhang, Zhaolong Xiang, Xiaodi Li, Engang Wang. Spinodal decomposition in Fe-25Cr-12Co alloys under the infl uence of high magnetic fi eld and the effect of grain boundary. Nanomaterials (Basel). 2018;8(8): 578. DOI: https://doi.org/10.3390/nano8080578
 Zayonchkovskiy V., Kyaw A. K., Milyaev, I., Perov N., Prokhorov I., Klimov A., Andreev A. (2019). Thin metal fi lms with dispersion-hardening magnetic layers of Fe–Cr–Co alloy. Kondensirovannye Sredyi Mezhfaznye Granitsy = Condensed Matter and Interphases. 2019;21(4): 505–518. DOI: https://doi.org/10.17308/kcmf.2019.21/2362
 Миркин Л. И. Справочник по рентгеноструктурному анализу поликристаллов. М.: Физматгиз; 1961. 863 с.
 Сайт компании NanoFocus. Режим доступа: https://m.nanofocus.de/en/
 Сайт компании ООО “ГЕО-НДТ”. Режим доступа: https://www.geo-ndt.ru/pribor-6855-rentgenoflyorescentnii-analizator-metekspert.htm
 Справочник по цветным металлам. Режим доступа: https://libmetal.ru/index.htm
 Сайт «Всё о металлургии». Режим доступа: http://metal-archive.ru/vanadiy/955-mehanicheskiesvoystva-vanadiya.html
 Громов Д. Г. Мочалов А. И., Сулимин А. Д., Шевяков В. И. Металлизация ультрабольших интегральных схем. М.: БИНОМ; 2012. 277 с.
 Лякишев Н. П., Банных О. А., Рохлин Л. Л. Диаграммы состояния двойных металлических систем: Справочник в трех томах. М.: Машиностроение; 1997. 872 c.
 Кекало И. Б., Самарин Б. А. Физическое металловедение прецизионных сплавов. Сплавы с особыми магнитными свойствами. M.: Металлургия; 1989. 496 с.
 ГОСТ 24897-81. Материалы магнитотвердые деформируемые. Solid magnetic deformed materials. Marks. М.: Издательство стандартов; 1981. 21 с.
 Bragg W. L. The diffraction of short electromagnetic waves by a crystal. Proceedings of the Cambridge Philosophical Society, 17, 43–57 (1913). Communicated by Professor Sir J. J. Thomson. Read 11 November 1912. In: X-ray and Neutron Diffraction. Elsevier; 1966. p. 19–125. DOI: https://doi.org/10.1016/b978-0-08-011999-1.50015-8
 Кремний. Физическая энциклопедия. Гл. ред. А. М. Прохоров. М.: Советская энциклопедия; 1990. 704 с.
 Vompe T. N., D’yakonova N., Milyaev I., Prutskov M. Kinetics of s-phase formation in a strain aging hard magnetic Fe-33% Cr-12% Co-2% Cu alloy. Russian Metallurgy (Metally). 2012;(1): 55–57. DOI: https://doi.org/10.1134/s0036029512010168
 Генералова К. Н., Ряпосов И. В., Шацов А. А. Порошковые сплавы системы Fe-Cr-Co, термообработанные в области «гребня». Письма о материалах. 2017;7(2): 133–136. DOI: https://doi.org/10.22226/2410-3535-2017-2-133-136
 Медь. Физическая энциклопедия. М.: Советская энциклопедия; 1992. 672.
 International Centre for Diffraction Data (ICDD).Режим доступа: www.icdd.com
 Козвонин В. А., Шацов А. А., Ряпосов И. В. Поликомпонентные концентрационнонеоднородные сплавы системы Fe–Cr–Co–Si–B повышенной плотности. Вестник ПНИПУ. Машиностроение материаловедение. 2016;18(4): 188–202. DOI: https://doi.10.15595/2224-9877/2016.4.14