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With the growing demand for nickel in the stainless steel and battery industries, conventional methods of extracting nickel from ores face challenges such as high production costs and environmental concerns. This study proposes a new process for the recovery of nickel metal and the production of nickel–iron alloys from nickel-bearing scrap. The reduction rates of nickel and iron oxides were investigated by optimizing the roasting temperature, time, and C/O ratio, and the process was optimized using response surface methodology (RSM). Through melt experiments on the reduced materials, the Ni–Fe particles were spontaneously aggregated driven by the Gibbs free energy change, which promoted their transfer to the metallic phase, and the recovery of metallic nickel was obtained to be 98.46%, with the nickel content of the nickel–iron alloy being about 24.61 wt%. By combining reduction melting and vitrification, the efficient recovery of metallic nickel and the production of ferro-nickel alloy were achieved, while the prepared glass slag showed low nickel content and dense amorphous structure with good environmental stability and safety. This study provides a new technical method for the comprehensive utilization of nickel-containing waste slag with significant environmental and economic benefits. [ABSTRACT FROM AUTHOR]

The document is a contents list from the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. It includes a variety of research papers on topics such as crystal structures, metal-organic frameworks, and crystal growth. The journal is published by The Royal Society of Chemistry, a leading chemistry community that reinvests profits back into the chemistry community. [Extracted from the article]

The investigation of the properties of Heusler compounds is an important task that will pave the way for new applications in various fields related to magnetics and thermoelectrics. This study examines the magnetic and thermoelectric properties of Fe2CoGa Heusler compounds prepared by casting and subsequent annealing. The Fe2CoGa Heusler compound was found to be ferromagnetic, with a large saturation magnetization of 110 emu/g and a high Curie temperature of 1011 K. The Fe2CoGa Heusler compound was a good thermoelectric material, with a negative Seebeck coefficient of −44 μV/K, a low electrical resistivity of 0.60 μΩm, and a high-power factor of 3000 μW/mK2 at room temperature. The maximum power factor of 3230 μW/mK2 for the Fe2CoGa Heusler compound was obtained at 400 K. In order to improve the magnetic and thermoelectric properties of the Fe2CoGa Heusler compound, Fe2-xCo1+xGa (x = 0–1) Heusler compounds were also prepared by casting and subsequent annealing. In the Fe2-xCo1+xGa (x = 0–1) Heusler compounds, the saturation magnetization slightly decreased, but the Curie temperature increased with increasing Co content (x). As regards the thermoelectric properties, the electrical resistivity of the Fe2-xCo1+xGa (x = 0.25–1) Heusler compounds was smaller than that of the Fe2CoGa Heusler compound. The Seebeck coefficient and power factor of the Fe1.75Co1.25Ga Heusler compound were more significant than those of the Fe2CoGa Heusler compound. An increase in the Co content of the Fe2CoGa Heusler compound did not improve the saturation magnetization but improved the Curie temperature and thermoelectric properties of the Fe2CoGa Heusler compound. The Fe1.75Co1.25Ga Heusler compound exhibited a high-power factor value of over 4000 μW/mK2, which was comparable to that of the Bi2Te3 compound. [ABSTRACT FROM AUTHOR]

The surface segregation process and its influence on high-temperature corrosion of five alloys—Fe0.95Al0.05, Fe0.95V0.05, Fe0.90Al0.05V0.05, Fe0.95Ti0.05 and Fe0.95Ge0.05—were studied using X-ray photoelectron spectroscopy (XPS) and 57Fe Transmission Mössbauer Spectroscopy (TMS). To prepare the alloys with the highest surface concentration of solutes, the samples were annealed at elevated temperatures to induce the surface segregation process. After that, they were exposed to air at 870 K for 1 and 5 h. It was found that the Fe0.95Ti0.05 sample annealed at 1073 K had much better anti–corrosion properties than other alloys studied. This finding can be correlated with the extremely high concentration of titanium on the surface, which was more than four times that of iron. In contrast to other alloys studied in this work, the passive layer formed on the surface of Fe0.95Ti0.05 greatly enhanced its resistance to corrosion. [ABSTRACT FROM AUTHOR]

The centrifugal atomization process is a rapid solidification method that achieves high cooling rates. Although this technique is typically used to produce common metal powders, it has not been extensively explored for amorphous powder production, despite its clear advantage of generating nearly perfect spherical particles, which is beneficial for subsequent powder consolidation. In this paper, a characterization of three iron-based alloys from the Fe-Si-B system, specifically Fe91.72Si5.32B2.96 (wt%), Fe87.37Si6.94B2.49Cr2.46C0.75 (wt%), and Fe89.41Si2.02B1.13P5.89C1.55 (wt%), produced by centrifugal atomization, is presented. The amorphous fractions of the powders were quantified using DSC, with further characterization performed via optical microscopy, SEM, and XRD. The amorphous fractions increased with the addition of Cr, C, and P, reaching up to 90% in the Fe89.41Si2.02B1.13P5.89C1.55 alloy for particles of <100 μm. The onset cooling rates were estimated to be approximately 10⁶ K/s for Fe91.7Si5.32B3, 10⁵ K/s for Fe87.36Si6.9B2.48Cr2.45C0.75, and 10⁴ K/s for Fe89.41Si2.02B1.13P5.89C1.55, respectively. [ABSTRACT FROM AUTHOR]

This review aims to comprehensively and systematically analyze the anodic oxidation process to form nanostructured oxide films on the surface of the most technologically relevant Fe-based alloys and steels. A special emphasis is put on detailed analysis of the mechanisms of the anodic formation of Fe-based nanostructured materials. The effect of anodizing parameters including the type of Fe-alloy, electrolyte composition, potential/current regimes, as well as various post-treatment procedures (including annealing treatment) on the growth, morphology, composition, and properties of the resulting oxide films is discussed in detail. Examples of possible applications of the anodic films grown on Fe-alloys in various fields including photocatalysis, energy storage, sensors, biomedicine, and others are also provided. Finally, current trends, challenges, and perspectives in the anodizing of Fe-alloys are addressed. [ABSTRACT FROM AUTHOR]

Green practices serve as a mechanism to enhance Industry 4.0 from a sustainability perspective, particularly in sectors where environmental effect is significant. This issue is particularly significant for european ferrous foundries that face significant challenges due to increasing competition and tightening environmental laws. Despite technological innovations and legal requirements, they are still remarkable sources of pollution and hazardous emissions. Organic binders, a group of petroleum-derived resins, are widely used for manufacturing sand molds and cores—fundamental elements in the manufacturing process—but their use is problematic due to the release of toxic substances both during their use and the pouring of the metal. Inorganic binders, derived from sodium silicate and other geopolymers, represent a possible solution, thanks to the near-zero emission levels that they exhibit in both of these phases. These binders are nowadays commonly used in non-ferrous metal foundries, such as aluminium ones, but their use in ferrous foundries is limited due to the increased mechanical resistence that they present at high temperatures (characteristics of ferrous alloys) that make sand residues difficult to remove from the castings, and their storage time is limited due to their low resistance to humidity. Research and technical innovation have made improvements in these aspects, but the scalability of these solutions in iron and steel foundries remains unclear. This paper analyses responses to a questionnaire that 90 ferrous foundries from eight European countries answered. The aim of the survey was to understand the characteristics of the firms and their relationship with inorganic binders. In the conclusion, in addition to a summarisation of the data that emerged in the analysis, the possibilities that modern simulation and management tools offer to handle this transition are discussed, with a particular focus on the potential benefits arising from the possible use of simulation models. [ABSTRACT FROM AUTHOR]

It is difficult to fine-tune the atomic local structure and magnetic domain structure globally to evade the saturation magnetization (Bs)- coercivity (Hc) trade-off in amorphous alloys with high-Fe content. Herein, a unique pulse current training is introduced to optimize the soft magnetic properties of Fe-based amorphous alloys, achieving 1.78 T Bs and 1.6 A/m Hc in Fe83.3Si4B8P4Cu0.7. Structural analysis shows that low coercivity is due to the almost no pinning-sites magnetic domain structures despite a relative large grain size of 25 nm. Training accumulates energy to activate soft regions and rearrange structure, eliminating quenching-induced stresses and inhomogeneities to minimize reversal pinning. IMPACT STATEMENT: Pulse current training offers a promising and efficient approach to address the saturation magnetization-coercivity trade-off issue in Fe-based soft magnetic amorphous alloys by accumulating energy to gradually modulate microstructures. [ABSTRACT FROM AUTHOR]

This work presents a process for the creation of emitter structures for liquid metal ion sources based on suspensions of iron and nickel in gallium-based room temperature liquid metal alloys. The process does not require needle etching or vacuum wetting of the emitter. Tip radii of less than 3 μm have been achieved. In addition, first measurements and observations from single emitter emission experiments are presented, including current-voltage characteristics, vacuum stability, degradation mechanisms and first thruster characteristics for the use in field emission electric propulsion. The impedance of the magnetic liquid metal emitters was found to correlate with the mass fraction of particles suspended in the liquid metal. Total impedances up to 30 MΩ have been achieved, indicating the feasibility of emitter clustering. Thrust measurements were performed with a commercial of the shelf load cell and verified in a dedicated setup for field emission electric propulsion testing, featuring a sub micro newton counterbalanced double pendulum thrust balance. [ABSTRACT FROM AUTHOR]

Martensite forms by a displacive mechanism of transformation; when it first forms all the carbon atoms that it inherits from parent austenite are ordered on only one of three sub-lattices of octahedral interstitial sites resulting essentially in a body-centred tetragonal crystal structure. At higher temperatures, however, the carbon atoms disorder and martensite becomes cubic. The literature on order–disorder transition has been reviewed. It has been highlighted that the c/a ratio of martensite is not independent of the concentration of substitutional solutes. Tetragonal martensite in interstitial-free ferrous alloys has also been discussed. The ordered arrangement of carbon atoms leads to conditional spinodal decomposition during the early stages of tempering. Finally, tetragonal bainitic ferrite and its higher solubility of carbon are discussed. [ABSTRACT FROM AUTHOR]

There is a growing focus on sustainability, characterized by making changes that anticipate future needs and adapting them to present requirements. Sustainability is reflected in various areas of materials science as well. Thus, more research is focused on the fabrication of advanced materials based on earth-abundant metals. The role of iron and its alloys is particularly significant as iron is the second most abundant metal on our planet. Additionally, the electrochemical method offers an environmentally friendly approach for synthesizing multifunctional alloys. Thus, iron can be successfully codeposited with a targeted metal from complexing electrolytes, opening a large horizon for a smart tuning of properties and enabling various applications. In this review, we discuss the practical aspects of the electrodeposition of iron-based alloys from complexing electrolytes, with a focus on refractory metals as multifunctional materials having magnetic, catalytic, mechanical, and antimicrobial/antibacterial properties with advanced thermal, wear, and corrosion resistance. Peculiarities of electrodeposition from complexing electrolytes are practically significant as they can greatly influence the final structure, composition, and designed properties by adjusting the electroactive complexes in the solution. Moreover, these alloys can be further upgraded into composites, multi-layered, hybrid/recovered materials, or high-entropy alloys. [ABSTRACT FROM AUTHOR]

The article presents the results of studies into the physical and mechanical properties of a material obtained by metallurgical smelting according to a technological scheme for creating alloys based on mineral raw materials of Yakutia. It was found that, in terms of its physical and mechanical properties, the alloy belongs to the class of cast tool steels according to GOST 1435-99. The fine-grained homogeneous structure of the alloy indicates its improved physical and mechanical properties. The ultimate tensile strength and hardness of the material correspond to the values of high-quality carbon steels after normalization. The feasibility of using iron ores of sedimentary origin from the Mene-Aldan ore occurrence in the development of tool cast steels and alloys has been confirmed. [ABSTRACT FROM AUTHOR]

Earth's inner core exhibits an unusually high Poisson ratio and noticeable elastic anisotropy. The mechanisms responsible for these features are crucial to understanding the nature of Earth's core. Although different mechanisms have been proposed, few can explain both observations simultaneously. The results of this study indicated that the crystal with noticeable shear softening would have strong anisotropy and an exceptionally high Poisson ratio simultaneously. Body-centered-cubic (bcc) iron exhibits shear instability at inner-core pressures and can be dynamically stabilized by high temperature and the presence of light elements. The bcc-lattice iron alloy could have strong anisotropy and a Poisson ratio of Earth's inner core before shear instability. Identifying which light elements can stabilize the bcc-lattice iron alloy will provide an independent constraint on the chemical composition of the inner core. [ABSTRACT FROM AUTHOR]

Over the past few years, a variety of melting casting projects have been performed, in collaboration with industries and universities. Concentrated alloys and nonmetallic compounds were studied including high-Si cast iron, high-Mn steel, Al-added stainless steel, high-entropy alloy, Permalloy 80 Ni alloy, Stellite Co alloy, steelmaking slag, and lithium iron phosphate (LFP). A melt synthesis of LFP was developed. Cooling curves were measured using the thermal analysis cup method and differential thermal analysis. In addition, the phase diagrams of alloys were calculated using Thermo-Calc. This paper draws on some examples of the measured cooling curves to illustrate the thermal behaviors of melts, along with a quick review of each project. [ABSTRACT FROM AUTHOR]

Three kinds of SiMo ductile iron samples with Nb/V alloying were prepared by the sand casting method. The microstructure and mechanical properties were evaluated via optical microscopy (OM), scanning electron microscopy (SEM) and an electronic universal testing machine. The metallographic analysis showed that Nb/V addition had a negligible effect on the graphite morphology and nodularity of the SiMo ductile iron, but the pearlite content increased and the size of the ferrite decreased. There are many Nb/V-rich carbides inside the ferrite grains and at the interface of the pearlite in ductile iron containing Nb/V. The tensile testing results showed that the SiMo ductile iron sample with 0.17% V addition had better mechanical properties at room and high temperatures. For SiMo ductile iron, the tensile strength (Rm), yield strength (Rp0.2), elongation after fracture (A) and Brinell hardness at room temperature are 631 MPa, 442 MPa, 8.9% and 222 HBW, respectively. The Rm, Rp0.2 and A at 650 °C were 202 MPa, 131 MPa and 21.8%, respectively. The better high-temperature performance of the sample containing 0.17% V is mainly attributed to the ability of V element to promote the precipitation and refinement of carbides, which can effectively improve the high-temperature strength of the matrix. [ABSTRACT FROM AUTHOR]

Hard-facing alloys increase the service life of components exposed to abrasive, erosive, or metal-to-metalwear conditions. Hard-facing is a metalworking process in which layers of a harder material are arc-welded onto a base metal. In particular, high-chromium hard-face weld deposit layers form a strong metallurgical bond with the substrate steel plate, enhancing the resistance to abrasive loadings. Metallurgical and microstructural analysis is conducted to improve the performance of such bi-layered metal structures. The discussion of an HC-O hard-face alloy deposited on S235 steel substrate plates is presented here, focusing on the characterization of the coating microstructure. The study establishes the relationship among the chemical composition, 'as-clad' microstructure, and hardness properties of the investigated high chromium Fe -- 27 wt.% Cr -- 5 wt.% C hard-facing alloy. [ABSTRACT FROM AUTHOR]

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The application of hydrogen (H2) and methane (CH4) as gaseous reductants for pure chromite (FeCr2O4) is reviewed in four theoretical approaches. These approaches are evaluated against the conventional process, where the sole reductant is a solid carbon (C) source. The sustainability is measured by gaseous carbon monoxide (CO(g)) formation, determined by the reaction stoichiometry of each theoretical approach. Decreased CO(g) formation is critical for alleviating the adverse environmental impact of ferroalloy production. The prereduction of FeCr2O4 by H2, followed by reduction by CH4 shows the largest decrease in CO(g) formation, i.e., a 75% decrease, compared to the conventional process. Furthermore, the H2‐based prereduction and CH4‐based primary reduction occur at lower temperatures than C‐based reduction, due to kinetic advantages, and thus decrease energy consumption. The overview discusses the environmental impact of substituting C with H2 and CH4 and briefly discusses how it can be implemented in industry. [ABSTRACT FROM AUTHOR]

The objective of the present review is to comprehend the driving force and significance of molybdenum (Mo) utilization in the ferrous powder metallurgy (PM) industry. Although it dates back to 1960, the last four decades are crucial, wherein the full potential of Mo in ferrous PM parts is recognized. Thus, peer‐reviewed publications, conference presentations, and authoritative reports from this period are mainly considered in this review. The review is limited to discussing the influence of Mo on the industry‐relevant attributes, such as hardenability, powder compressibility, sintering performance, mechanical and tribological properties, and machining of ferrous PM alloys. It has been elucidated from the review that Mo alloying is favored in the ferrous PM industry because of its excellent hardenability outcomes while insignificant effects on powder compressibility and lack of oxygen sensitivity that aid in easy sintering of the alloys. Hardenability is a critical property, and it improves the mechanical and tribological performance of Mo‐containing ferrous PM alloys, as discerned herein. It has also been realized that Mo contributes toward improving the machinability of ferrous PM alloys in the form of MoS2. Finally, research opportunities in the utilization of Mo in ferrous PM alloys are discussed in this report. [ABSTRACT FROM AUTHOR]

The strategic regulation of the electronic properties and coordination environment of single‐atom sites through the integration of metal nanoclusters emerges as a promising route to enhance the oxygen reduction reaction (ORR) performance of Fe–N–C materials. Here, a catalyst (FeIn–NC) is successfully developed in which Fe–N–C materials encapsulate Fe–In alloy nanoclusters, and it shows excellent ORR activity and durability under alkaline conditions, with a high half‐wave potential of 0.924 V (vs RHE) and a zinc–air battery power density of 202.1 mW cm−2, superior to commercial Pt/C catalysts. Theoretical calculations unravel that the synergistic interaction between the Fe–In alloy and the FeN4 single‐atom site modifies the electronic structure and charge distribution at the FeN4 site, thereby enhancing the electrocatalytic activity and durability of the ORR. Potential‐dependent microkinetic modeling (MKM) further discloses the ORR mechanisms on the identified FeN4 sites. This work provides a viable strategy for the ORR improvement of Fe–N–C materials via p‐block metal‐based alloy nanoclusters. [ABSTRACT FROM AUTHOR]

Results of the study of the crystal structure and temperature and field dependences of magnetization, coercivity, and parameters of magnetocaloric effect of the polycrystalline TbCo2-based compounds with Y and Fe, which substitute for the constituents in the 4f and 3d magnetic sublattices, are reported, respectively. The effect of the substitutions on the existence and value of crystal lattice rhombohedral distortions of the compositions studied at room temperature is shown. The substitution of Fe for 4–8 wt % Со was found to lead to the appearance of pronounced low-temperature maximum in the temperature dependence of the isothermal magnetic entropy change ∆Sm at temperatures 100–200 K below the Curie temperature. As a result, the increase in the refrigeration capacity coefficient q and working temperature range ∆TFWHM is observed for the samples. At an iron content of ≥16 wt %, and also when Y substitutes for Tb, the decrease in q takes place because of the weak response of 4f-magnetic sublattice on the applied magnetic field near the low-temperature maximum. The obtained parameters of magnetocaloric effect are compared with those for the related compounds with the other rare-earth metals. [ABSTRACT FROM AUTHOR]

The article presents the results of our study of protective cermet coatings obtained by the method of electric spark alloying on a dental instrument (excavator) using SHS (self-propagating high-temperature synthesis) electrodes based on TiC-NiCr. The influence of discharge energy during electric spark alloying on the roughness, thickness, and proportion of the TiC carbide phase in the cermet coating has been established. It has been shown that during electric spark alloying, the material of the used SHS electrode and the surface of the substrate melt, their convective mixing occurs, and during crystallization, coatings are formed that consist of a strengthening phase TiC and iron-based solid solutions: Fe 9.64 Ti 0.36 , F 1.88 C 0.12 , and Cr-Ni-Fe-C. It has been found that the maximum size of TiC grains is formed on the surface of the cermet coating, and as they approach the substrate, their size decreases to less than 10 nm. It has been found that the microhardness of the surface of the resulting cermet coatings increased to 6.2 times compared to the microhardness of the original metal base, which was 2 GPa. The results of scanning electron microscopy and energy dispersive analysis of the surface of samples with and without cermet coating before and after corrosion tests are presented. The influence of disinfectants (2 and 100 % Trilox, Wendelin, MegaDes-ortho) on the corrosion resistance of samples with and without developed protective cermet coatings at room and elevated temperatures up to 50 °C and their exposure for 120 h has been established. [ABSTRACT FROM AUTHOR]

Carbon dioxide is emitted in several industrial processes and contributes to global warming. One of the industries that is considered a significant emitter is metallurgy. Therefore, it is necessary to search for and implement methods to reduce its emissions from metallurgical processes. An alternative option to the use of conventional coke, which is produced solely from fossil coal, is the utilization of bio-coke. The production of bio-coke involves the use of coking coal and the incorporation of biomass-derived substances such as biochar (charcoal). The article presents the results of the research on the influence of the biochar addition on the structural, textural, and technological properties of produced bio-coke. Research on the production and analysis of the properties of the obtained bio-coke aimed at assessing the potential possibilities of applying it in the process of a carbothermal reduction of manganese ore in order to smelt ferroalloys. Studies have shown that biochar addition to the coking blend in an amount of up to 20% allows a bio-coke characterized by properties enabling the mentioned use to be obtained. Bio-coke was characterized by higher CO2 reactivity index (CRI), lower post-reaction strength (CSR), and higher reactivity to synthetic manganese ore than regular metallurgical coke. In the context of industrial applications of bio-coke, it is necessary to verify its production and use on a pilot and industrial scale. [ABSTRACT FROM AUTHOR]

This review explores the advancements in additive manufacturing (AM) of biodegradable iron (Fe) and zinc (Zn) alloys, focusing on their potential for medical implants, particularly in vascular and bone applications. Fe alloys are noted for their superior mechanical properties and biocompatibility but exhibit a slow corrosion rate, limiting their biodegradability. Strategies such as alloying with manganese (Mn) and optimizing microstructure via laser powder bed fusion (LPBF) have been employed to increase Fe's corrosion rate and mechanical performance. Zn alloys, characterized by moderate biodegradation rates and biocompatible corrosion products, address the limitations of Fe, though their mechanical properties require improvement through alloying and microstructural refinement. LPBF has enabled the fabrication of dense and porous structures for both materials, with energy density optimization playing a critical role in achieving defect-free parts. Fe alloys exhibit higher strength and hardness, while Zn alloys offer better corrosion control and biocompatibility. In vitro and in vivo studies demonstrate promising outcomes for both materials, with Fe alloys excelling in load-bearing applications and Zn alloys in controlled degradation and vascular applications. Despite these advancements, challenges such as localized corrosion, cytotoxicity, and long-term performance require further investigation to fully harness the potential of AM-fabricated Fe and Zn biodegradable implants. [ABSTRACT FROM AUTHOR]

Background: Ferrosilicon alloys are a mixture of iron and silicon. It offers better iron characteristics such as hardness, strength, and resistance to corrosion and heat by adding alloys of ferrosilicon to steel and cast iron. The ferrosilicon alloy industry workers are exposed to many hazards that can affect their respiratory function due to exposure to silica dust which is present in all steps in this industry mainly from furnaces, in addition to exposure to irritant gases in refining and casting operations. Thus, the current study was conducted to estimate the respiratory problems prevalence especially silicosis among workers of ferroalloy factories. Results: All studied workers (100%) were males with a mean (± SD) age of 50.15 ± 5.77 years. Seventy percent of workers had been working for ≥ 20 years and 76.4% were working in places with high levels of exposure. About one-third of the studied workers were diagnosed with silicosis. There was a statistically significant higher occurrence of silicosis among workers aged ≥ 50 years old. Work duration and level of exposure were significant predictors of silicosis occurrence among studied workers. Conclusion: Ferroalloy factory work environment affects the respiratory health of the workers and impairs their pulmonary function. It may increase the risk of developing silicosis which impacts the effectiveness of their work and quality of life. Workers in ferroalloys factories must receive regular medical care, and safety precautions are recommended. Trial registration: ClinicalTrials.gov. NCT05374148. Registered May 13, 2022. [ABSTRACT FROM AUTHOR]

A promising way to solve the problems of hydrogen storage for energy systems is in the use of metal hydrides, especially, the ones on the basis of titanium—iron alloys characterized by low cost and easily available feedstock. However, hydrogen storage performances of TiFe-based intermetallic alloys are very sensitive to a number of factors including contamination of the final product with non-metallic impurities, first of all, oxygen. This work aimed at finding the ways to mitigate these undesired effects presents results of the experimental studies of chemical and phase composition, along with hydrogen sorption properties of the alloys Ti1 + xFe1 – yMy (x = –0.07...+0.19, y = 0–0.2, M = Mn, V) prepared using small-to-medium scale arc- and induction melting facilities from industrial-grade quality raw materials. The most effective way to decrease the oxygen contamination and improve the hydrogen sorption performance was found to be addition of minor amounts of a mischmetal deoxidizer to the starting charge followed by induction melting. Additional factors influencing on the properties of the studied alloys and discussed in this work are the details of the melting procedure and the base composition of the charge including Ti : Fe atomic ratio, type of the metal additive (M) substituting iron in the alloy, as well as possibility of formation of minor amount of the oxygen-containing intermetallic Ti4(Fe,M)2O1 – x (η-phase) known as efficient hydrogenation catalyst. [ABSTRACT FROM AUTHOR]

Classification of cast iron alloys based on graphite morphology plays a crucial role in materials science and engineering. Traditionally, this classification has relied on visual analysis, a method that is not only time‐consuming but also suffers from subjectivity, leading to inconsistencies. This study introduces a novel approach utilizing convolutional neural networks—MobileNet for image classification and U‐Net for semantic segmentation—to automate the classification process of cast iron alloys. A significant challenge in this domain is the limited availability of diverse and comprehensive datasets necessary for training effective machine learning models. This is addressed by generating a synthetic dataset, creating a rich collection of 2400 pure and 1500 mixed images based on the ISO 945‐1:2019 standard. This ensures a robust training process, enhancing the model's ability to generalize across various morphologies of graphite particles. The findings showcase a remarkable accuracy in classifying cast iron alloys (achieving an overall accuracy of 98.9 ± 0.4%—and exceeding 97% for all six classes—for classification of pure images and ranging between 84% and 93% for semantic segmentation of mixed images) and also demonstrate the model's ability to consistently identify and graphite morphology with a level of precision and speed unattainable through manual methods. [ABSTRACT FROM AUTHOR]

The method of constrained equilibria has already found extensive use for a good number of years in conjunction with the programmers library ChemApp and freely adaptable ASCII based thermodynamic datafiles. In the present paper a method is demonstrated which permits the application of this method in the framework of the Integrated Thermodynamic Databank System (ITDS) FactSage. Both, modules which interact with the databases and modules which carry out thermodynamic calculations are used, thus emphasizing the aspect of integration in the ITDS. In the paper a link will be established between original thoughts by J.W. Gibbs concerning the definition of the components of a system and kinetic inhibitions in the system and the method of constrained equilibria as such. Furthermore, reference is made to Mats Hillerts use of driving forces in complex (non-)equilibrium cases. A number of application cases with different degrees of complexity will be demonstrated. These range from partially or fully constrained complex equilibrium calculations to phase diagrams with new types of axis variables. [ABSTRACT FROM AUTHOR]

The study and improvement of the corrosion resistance of materials used in concentrated solar power plants is a permanent field of research. This involves determining their chemical stability when in contact with heat transfer fluids, such as molten nitrate salts. Various studies indicate an improvement in the corrosion resistance of iron-based alloys with the incorporation of elements that show high reactivity and solubility in molten nitrate salts, such as Cr and Mo. This study analyzes the kinetic and thermodynamic aspects of the beginning of the corrosion process of ferritic steels immersed in Solar Salt at 400, 500, and 600 °C. The analysis of the kinetic data using the Arrhenius equation and the Transition State Theory shows that an increase in the Cr/Mo ratio reduces the activation energy, the standard formation enthalpy, and the standard formation entropy. This indicates that its incorporation favors the degradation of steel; however, the results show a reduction in the corrosion rate. This effect is possible due to a synergistic effect by the formation of insoluble Fe-oxide layers that favor the formation of a Cr oxide layer at the Fe-oxide-metal interface, which limits the subsequent oxidation of Fe. [ABSTRACT FROM AUTHOR]

A Mössbauer study of (Fe30Cu70)96B4 (FeCuB) alloys, obtained previously by induction casting and subsequent ball milling up to 60 h, was conducted at room temperature (RT). 57Fe Mössbauer spectra were fitted using three components: two magnetic hyperfine field distributions (HFD) with average Bhf1 and Bhf2 values plus a quadrupolar distribution (QSD) to account for disorders that are induced during the milling process. Thus, these components are respectively associated with a magnetically coupled α-iron phase (Bhf1 component), a Fe-rich containing phase with Bhf2 value smaller than that found for α-Fe (Bhf1 component), consequently attributed to the FeCuB alloy and, a Fe-poor phase responsible for the paramagnetic phase (QSD). The Bhf2 component shows fcc-type features, and the milling process produces an increase of the paramagnetic phase at the expense of the α-iron (bcc). [ABSTRACT FROM AUTHOR]

Basing on Mössbauer studies of various iron, stony-iron and stony meteorites, we considered a possible relationship of the ranges of magnetic hyperfine field (Heff), Fe-Ni-Co phases and the ranges of Ni concentration in these phases. We suppose that possible relationship of the ranges of Heff with Fe-Ni-Co phases and with the ranges of Ni concentration can be taken as follows: ~345 kOe ≤ Heff ≤ ~365 kOe for the α2-phase (~ 8–25 at% of Ni), ~ 327 kOe < Heff ≤ ~345 kOe for the α-phase (up to 7 at% of Ni), ~ 283 kOe ≤ Heff ≤ ~327 kOe for the γ-phase (~ 26–48 at% of Ni) with the values of ~ 283 kOe ≤ Heff ≤ ~295 kOe which may also be associated with the ordered γ-FeNi(Co) phase (~ 48–52 at% of Ni). The paramagnetic γ-Fe(Ni, Co) phase with ~ 29–33 at% of Ni has the values of isomer shift (δ) in the range of ~ − 0.200 mm/s < δ < ~0.150 mm/s. [ABSTRACT FROM AUTHOR]

Molecular aromatic corrosion inhibitors are frequently applied to slow down the corrosion of iron, its alloys and numerous other metallic materials. This case study with three representative aromatic inhibitors and a pure iron electrode aims at the verification of the reported conclusions regarding these inhibitors and at the verification and comparison of electrochemical corrosion assessment methods with attention to differences between iron alloys (steels) and pure iron possibly related to the presence/absence of alloying elements and non-iron impurities. [ABSTRACT FROM AUTHOR]

New methods of materials separation and metal production utilizing sulfide chemistries may support a paradigm shift in sustainable metallurgy. We leverage sulfidation with elemental sulfur, aluminothermic reduction, and slag refining to obtain a chromium–nickel–molybdenum ferroalloy and stainless steel using a sulfide-based route without direct greenhouse gas emissions. The absence of carbothermic reduction from the mineral, concentrate, and matte feedstocks tried herein indicates that argon-oxygen-decarburization may no longer be necessary to refine stainless steel products. [ABSTRACT FROM AUTHOR]

The melting and motion of ferroalloys play a crucial role in the mass transfer and homogenization of molten steel in ladles. Heat transfer, melting, and solidification behavior of an alloy affect its size, thereby altering its motion within the gas-stirring ladle. This study established a heat transfer and solidification-melting model for alloy particles in high-temperature metal liquids. The computational fluid dynamics (CFD) method was used to simulate the fluid within the ladle, and the discrete element method (DEM) was employed for the alloy particles. This coupling approach elucidates the motion trajectories of different types of alloys in molten steel under flow and heat exchange, particle heating, melting, and shrinkage conditions. Furthermore, the effects of alloy size, initial alloy temperature, molten steel flow rate, and molten steel temperature on the melting behavior of different types of alloys were investigated. The results showed that the melting time exponentially increased with increasing alloy size or decreasing molten steel flow rate. Moreover, the alloy melting time decreased with increasing initial alloy temperature or molten steel temperature. The impact of these factors on the melting of FeCr, FeMn, FeSi, and Al alloys was also evaluated. Furthermore, FeSi and Al alloys added at different positions in the ladle with symmetric dual gas bottom blowing had a residence time of only 1 second in the molten steel and did not completely melt. These findings indicate that FeSi, Al, and FeCr alloys should be added at the 0.4R position in the symmetrical plane. Furthermore, the − 0.4R or − 0.2R positions are more favorable for the melting of FeMn. [ABSTRACT FROM AUTHOR]

In this research, high-Cr cast irons alloys were developed and cast. The compositions were modified by the addition of niobium (≈ 3 wt pct Nb), molybdenum (≈ 3 wt pct Mo), and a combination of both (≈1 wt pct Mo–2 wt pct Nb) to evaluate the production of reinforcing carbides. Through quantitative image analysis, the size, volume fraction, and mean free path of M7C3 eutectic carbides were determined and correlated to the microstructural characteristics, as well as to the mechanical and wear properties of the alloys. The thermodynamic evaluation predicted that the Nb nuclei precipitated in the molten liquid previously to the other phases and that the higher Nb content offered higher nucleation and growth potential for their nuclei. The microstructural examination showed that the morphology of Nb-rich carbides varied from nodular (homogeneous dispersion) to a flake-like shape morphology (inhomogeneous dispersion) as the Nb content decreased. The Nb–Mo combination produced MC carbide composed mainly of Nb-containing bound Mo. Fracture surfaces indicated that this carbide worked as a stress concentrator, causing a noticeable matrix/carbide debonding, reducing the impact energy. NbC carbide had a beneficial effect on wear resistance, due to its better distribution than the other reinforcing carbides M2C (Mo-rich) and MC. [ABSTRACT FROM AUTHOR]

Ductile iron has comprehensive properties that are similar to steel, making it is widely used for core components in key equipment such as the automotive engine crankshafts, machine tool beds, cylinder liners, and brake levers. However, the material has inherent structural defects such as the cracks, shrinkage, and subcutaneous porosity, which can easily lead to parts failure due to fracture, wear, and corrosion. Therefore, it is significant to repair and strengthen the surface for ductile iron. Laser cladding has several advantages, including low thermal deformation and high bond strength, which provides an effective method for repairing and strengthening ductile iron parts. For parts with serious area damage, a single-track cladding cannot meet the requirements for use, multi-track overlapping and multilayer cladding processes are typically used for repair and strengthening. Nickel-based and cobalt-based alloys are often utilized to reinforce the surface of core parts due to high-temperature resistance, oxidation resistance, and low deformation. The Co12 lattice structure is susceptible to thermal transformation, which can cause cracking for the cladding layer, making it is primarily used as a top cladding material. In this study, IN625 powder was used as the base of multilayer cladding, followed by Co12 powder. The hardness, wear resistance, corrosion resistance, and other properties for cladding layer were analyzed. The results show that the multi-track overlapping process has a high metallurgical bonding effect, and the grain in the lap remelting area is refined. Through multilayer cladding, the overall hardness for the ductile iron exceeds 500 HV, and the mechanical properties are significantly improved. The corrosion rate reduces by 395.5 times, and the corrosion resistance is improved. [ABSTRACT FROM AUTHOR]

In the present work, the effect of the Sn addition (0.01 to 0.118) wt.% on the mechanical and microstructural properties of the copper base gray cast iron alloys has been investigated, and the fracture surface obtained from the tensile test was examined. The results show that the Sn alloying improved and refined the pearlitic structure in the alloys and causes graphite flakes to thin. The optimum pearlitic content in the microstructure is obtained with the 0.076 wt. % Sn-alloyed gray cast iron (T3). The T3 alloy also shows the optimum mechanical properties such as tensile strength of 380 MPa, hardness of 225 BHN, and impact strength of 3.2 Joules. The wear resistance is also high in the T3 alloy compared to all the samples. The fracture analysis shows that the Sn alloying causes more brittle fractures in the gray cast irons compared to the without alloying condition. [ABSTRACT FROM AUTHOR]

In this paper, two kinds of coatings (iron-based and cobalt-based) were successfully prepared on the surface of AISI 304 stainless steel using laser cladding technology as substitute materials with excellent wear resistance and corrosion resistance, respectively. Subsequently, the phase composition, microstructure, crystallographic texture, microhardness distribution, wear behavior and corrosion behaviour of the two coatings were investigated. The results showed that the iron-based coating mainly composed of α-Fe and Cr23C6 phases, while the cobalt-based coating mainly composed of γ-Co and Cr23C6. There was no obvious texture in the two coatings, and the grain orientation showed a random characteristic. The grain size of iron-based coatings is greatly smaller than that of cobalt-based coatings. The average microhardness of the iron-based and cobalt-based coatings is 704 HV and 502 HV. The simultaneous effect of fine grain strengthening and second phase strengthening ensures high wear resistance of the iron-based coating. The combination of Cr-rich passive film and fine dispersed carbides ensures high corrosion resistance of the cobalt-based coating. [ABSTRACT FROM AUTHOR]

This review article reports the critical issue of reoxidation in clean steel production during secondary refining and continuous casting processes. Reoxidation presents substantial challenges to process stability and final product quality. Various sources of reoxidation, including exposure to oxidizing gases, reducible oxides in slag and refractories, and the presence of ferroalloys are explored. Fundamental reactions and their consequences, such as changes in steel composition, inclusion composition/morphology, and the formation of reaction products at the interface between liquid steel and refractory materials, are reviewed. High oxygen partial pressure on the refractory side is identified as a significant factor, particularly in tundish and continuous casting processes. To address reoxidation effectively, the review discusses modeling approaches like computational fluid dynamics and thermodynamic/kinetic modeling. In the industrial context, reoxidation in the tundish is mainly attributed to open‐eye formation in the tundish flux and reducible oxides like SiO2 in an insulating cover powder, for example, rice hust ash. Maintaining precise tundish flux control is crucial for steel cleanliness. In conclusion, this review highlights the multifaceted nature of reoxidation challenges in clean steel production. A comprehensive understanding of reoxidation mechanisms and the implementation of effective strategies are essential for achieving cleaner steel production. [ABSTRACT FROM AUTHOR]

Diamond‐like carbon (DLC) is an amorphous material widely used in industrial applications due to its chemical, mechanical, and tribological properties and, also, for decorative purposes. However, its low adhesion to ferrous alloys reduces its effectiveness in certain applications, necessitating the use of adhesion interlayers to reduce stresses at the interfaces and enhance the density of strong bonds. In this context, the factors that promote good adhesion in this system and specify the parameters must be understood in detail. Thus, the present study aims to assess the influence of the base pressure on the deposition of an amorphous silicon carbide adhesion interlayer between DLC coating and a ferrous alloy substrate. Microstructural, physicochemical, morphological, and mechanotribological analyses were conducted to understand the adhesion behavior in terms of structural and chemical aspects. In addition to the influence of the interlayer thickness, the elemental Si/C ratios and the relative oxygen content have an impact on the maximum load supported by the coatings, as well as the different delamination mechanisms generated in adhesion tests. [ABSTRACT FROM AUTHOR]

Iron–selenium (Fe–Se) alloys have potential as attractive biodegradable bone–implant materials, given the antitumor properties of Se in cancer prevention and therapy. However, the fabrication of Fe–Se alloys is challenging due to the volatility of elemental Se and the significantly different melting points of Se and Fe. In this study, we successfully fabricated Fe–xSe (x = 0.2, 0.4, 0.6, 0.8, and 1 wt.%) alloys using suction casting, with FeSe compounds as the Se source. The microstructures, tensile properties, corrosion behavior, biocompatibility, antibacterial ability, and antitumor properties of the Fe–Se alloys were evaluated. The microstructures of the Fe–Se alloys were composed of α–Fe and FeSe phases. Among the Fe–Se alloys, Fe–0.6Se showed the best combination of tensile properties, with a yield strength of 1096.5 ± 7.2 MPa, an ultimate tensile strength of 1271.6 ± 6.3 MPa, and a fracture strain of 15.6 ± 3.3 %, and a degradation rate of 56.9 ± 0.4 μm/year. Moreover, the Fe–0.6Se alloy showed superb antibacterial ability against S. aureus , antitumor activity against 143B osteosarcoma cells, and osteogenicity and biocompatibility toward pre–osteoblast MC3T3–E1 cells. In summary, adding 0.2–1.0 wt.% Se to Fe does not affect the growth of healthy cells but effectively inhibits the growth and reproduction of tumor cells, and the Fe–0.6Se alloy is promising for orthopedic applications owing to its unique combination of mechanical and biofunctional properties. This work reports on Fe-xSe (x = 0.2, 0.4, 0.6, 0.8, and 1 wt.%) alloys fabricated using suction casting. The microstructures of the Fe–Se alloys were composed of α-Fe and FeSe phases. Among the Fe–Se alloys, the Fe-0.6Se showed the best combination of tensile properties, with a yield strength of 1058.6 ± 3.9 MPa, an ultimate tensile strength of 1134.1 ± 2.9 MPa, and a fracture strain of 16.8 ± 1.5 %, and a degradation rate of 56.9 ± 0.4 μm/year. Moreover, the Fe-0.6Se alloy showed superb antibacterial ability against S. aureus , antitumor activity against 143B osteosarcoma cells, and significant osteogenic ability and biocompatibility toward pre-osteoblast MC3T3-E1 cells. In summary, the Fe-0.6Se alloy is promising for orthopedic applications owing to its unique combination of mechanical and biofunctional properties. [Display omitted] [ABSTRACT FROM AUTHOR]

The editorial discusses the complexities of solidification in metallic materials, emphasizing the importance of understanding variables like cooling rate and thermal gradient for predicting cast product performance. The special issue focuses on casting alloy design and characterization, with studies covering topics such as high-entropy alloys, Fe-based and Co-based multicomponent alloys, and unconventional rheocasting processes for Al-Si alloys. The research aims to establish correlations between processing, properties, and microstructures, offering insights into improving casting processes and developing high-quality cast products. The editorial concludes by highlighting the significance of microstructure in determining casting properties and the need for continued investigation in casting alloy design and characterization. [Extracted from the article]

The accumulation of copper in steel scrap is becoming an increasingly problematic issue in the steelmaking industry. Accordingly, the present study was undertaken to investigate the removal of copper from a liquid Fe–Cu alloy via tapping under vacuum. Furthermore, the impact of surface-active components sulfur and oxygen was examined. For this purpose, four Fe–0.5 wt% Cu alloys with varying oxygen and sulfur contents were melted and subsequently poured at a pressure of 100 Pa. The findings indicate that alloys with low oxygen and sulfur content exhibited enhanced copper evaporation. Additionally, the evaporation of other tramp metals, including manganese, phosphorus, and tin, was observed, and the influence of sulfur and oxygen on this process was discussed. Furthermore, the vacuum treatment conditions for copper evaporation in industrial settings were explored. [ABSTRACT FROM AUTHOR]

Process simulation was integrated with life cycle assessment to evaluate process efficiency and environmental impact of the production of manganese ferroalloys for various production modes and different ore mineralogies. Utilizing HSC Sim, the model was designed to evaluate the production process with or without a pretreatment step, where results for simulated cases using a four-zone ferromanganese furnace model were exported to openLCA for a complete life cycle assessment. Two main production scenarios were simulated: a closed ferromanganese furnace running on the duplex method and an open furnace running on the discard slag approach. The closed furnace scenario achieved a 17.5% reduction in energy consumption and a 16.2% decrease in direct CO2 emissions with CO-rich off-gas pretreatment. The open furnace scenario showed an 11.2% reduction in energy consumption with thermal solar energy pretreatment but no change in CO2 emissions. [ABSTRACT FROM AUTHOR]

Accurate knowledge of the phase transitions and thermoelastic properties of candidate iron alloys, such as Fe‐Si alloys, is essential for understanding the nature and dynamics of planetary cores. The phase diagrams of some Fe‐Si alloys between 1 atm and 16 GPa have been back‐extrapolated from higher pressures, but the resulting phase diagram of Fe83.6Si16.4 (9 wt.% Si) is inconsistent with temperature‐induced changes in its electrical resistivity between 6 and 8 GPa. This study reports in situ synchrotron X‐ray diffraction (XRD) measurements on pre‐melted and powder Fe83.6Si16.4 samples from ambient conditions to 60 GPa and 900 K using an externally heated diamond‐anvil cell. Upon compression at 300 K, the bcc phase persisted up to ∼38 GPa. The hcp phase appeared near 8 GPa in the pre‐melted sample, and near 17 GPa in the powder sample. The appearance of the hcp phase in the pre‐melted sample reconciles the reported changes in electrical resistivity of a similar sample, thus resolving the low‐pressure region of the phase diagram. The resulting high‐temperature Birch‐Murnaghan equation of state (EoS) and thermal EoS based on the Mie‐Gruneisen‐Debye model of the bcc and hcp structures are consistent with, and complement the literature data at higher pressures. The calculated densities based on the thermal EoS of Fe‐9wt.%Si indicate that both bcc and hcp phases agree with the reported core density estimates for the Moon and Mercury. Plain Language Summary: The compositions of the interiors of planetary bodies such as the Moon and Mercury can be inferred by examining how core analogue materials (e.g., Fe‐Si alloys) behave at high pressures and temperatures. However, phase transitions of Fe‐Si alloys under conditions relevant to the Moon and Mercury have only been inferred from the extrapolations of data acquired at higher pressures. Additionally, electrical resistivity measurements have suggested that Fe‐Si alloy containing 9 wt.% Si undergoes pressure‐induced changes that are not well understood. To clarify these ambiguities, we acquired XRD patterns of Fe‐9wt.%Si up to 60 GPa and 900 K using an externally heated diamond‐anvil cell. The results show that Fe‐9wt.%Si can exist in two different crystal structures, body‐centered cubic and hexagonal close‐packed, depending on the pressure‐temperature conditions. The transition between these structures occurs at different pressures for the pre‐melted and powder samples. By modeling how the volume of the sample changes with pressure and temperature, we found that the densities of the Moon's and Mercury's cores align closely with existing models, implying a substantial presence of Fe‐9wt.%Si. Key Points: New constraints on the phase diagram of iron with 9 weight percent silicon between 1 bar and 16 GPa are establishedThermal equations of state of body‐centered‐cubic and hexagonal‐closed‐packed Fe‐9wt.%Si are established up to 60 GPa and 900 KThe calculated core densities of the Moon and Mercury are consistent with previous estimates [ABSTRACT FROM AUTHOR]