Fe Sn Alloys Research Articles

A scoping investigation on debris bed formation with high-temperature melt simulant Fe-Sn

In hypothetical severe accidents of Nordic boiling water reactors (BWRs), the core melt (corium) has the potential to relocate to the lower head, leading to the failure of the reactor pressure vessel (RPV). Consequently, the corium, a molten mixture of either UO2-ZrO2 or Fe-Zr, is anticipated to undergo fuel coolant interactions (FCI) in a deep-water pool within the reactor cavity which is supposed to be flooded during severe accidents. The characteristics of the resulting debris bed play an important role in corium coolability that is paramount to accident stabilization and termination. This study is dedicated to characterizing the debris bed resulting from the FCI using Fe-Sn as the simulant of Fe-Zr. Compared with other simulants in our previous studies, the Fe-Sn alloy has a a higher melting point of 1130 °C and the same element of Fe as in prototypical Fe-Zr. The Fe-Sn is melted in a clay graphite crucible with glass coating layer to minimize contamination of molten materials by graphite. Argon containing 1.26 % hydrogen is employed as cover gas to avoid the oxidation of Fe-Sn at high temperature. The process of debris bed formation, including melt jet breakup, debris fragmentation, and fragments’ sedimentation on the pool bottom, is meticulously recorded using high-speed cameras. The porosity of the debris bed is determined in the post-test analyses using a three-dimensional laser scanner and a graduated water tank. The laser scanner data are also used to reconstruct the geometric appearance of the final debris bed. The debris particulates are sieved to obtain their size distribution. The chemical interaction between water and melt is examined by the SEM analysis. The experimental results show that the debris bed of Fe-Sn has significant differences from those of low melting point simulants (Sn-Bi, Sn, Zn) in our previous studies.

“Mobius strip-like” FeSn alloy: A novel highly-distorted 3D hierarchical porous anode for ultrafast and stable Li storage

Tin provides high specific capacity (994 mAh g−1) by forming Li4.4Sn in lithium-ion batteries (LIBs) yet exhibits poor electrochemical stability. Inspired by the miraculous “Mobius strip” with superior stress-relieving effect in the developable surface, herein, through a facile dealloying and sol-gel pyrolysis method, a “Mobius strip-like” highly-distorted C-wrapped 3D hierarchical porous FeSn integrated anode (HD-3D-HP FeSn@C) is initially designed and utilized to relieve the mechanical stress in Sn-based anode generated during lithiation-delithiation. The anodes are characteristic of highly-distorted bimodal pore-size distribution composed of microporous architecture and homogeneous nanopores on pore walls on the developable surface, which contribute to effective stress relief and rapid mass transfer. Moreover, the wrapped-C is of great significance for maintaining the anode structure and improving the stability of solid electrolyte interface (SEI). Therefore, the HD-3D-HP FeSn@C anodes display the ultrafast Li storage properties with high rate capability (0.23 mAh cm−2 at 10 mA cm−2) and good cycling stability (68.89 % of capacity retention after 1000 cycles at 1 mA cm−2, only ∼0.03 % capacity decay per cycle). This work provides a novel and universal anode design philosophy towards high-performance LIBs, which may shed light on the evolution of other secondary batteries beyond alkali metal batteries.

Mechanical Properties of Sintered Al–Sn–Fe Alloys

Mechanical Properties of Sintered Al–Sn–Fe Alloys

An effective method for recovering ultrafine SnO2, MgSn(OH)6, and Zn from complex iron tailings

The generation of complex tailings from iron mining is continuously increasing, reaching a reserve of 500 million tons. The iron tailings mainly contain 0.10–0.50 wt% ultrafine SnO2 (−9.6 μm, >50 %), acid-solule Sn (MgSn(OH)6) and 0.20–1.50 wt% Zn and are recognized as an important secondary Sn resource. Unfortunately, traditional mineral processing techniques have a low Sn recovery ratio. In this study, a novel method is proposed for effectively recovering Sn and Zn from complex iron tailings through reduction-sulfurization roasting, and their transformation behavior is determined. The results reveal that MgSn(OH)6 is first transformed into MgSnO3 at 1073 K, and SnO2 is reduced to SnO(g) and then sulfurized to SnS(g). COS acts as the main curing agent during the roasting process, which originates from the oxidation of FeS. As the temperature increases from 1173 to 1273 K, part of SnO2 can combine with CaO to form Ca2SnO4, and the generated CaSnO3 and MgSnO3 are further reduced to Sn(l) and Fe–Sn alloy. Meanwhile, ZnO and ZnS can be efficiently converted to Zn(g). Interestingly, the Fe–Sn alloy cannot be removed due to low Sn activity (a[Sn]). However, the Sn recovery ratio increases to 90 % due to low SnS partial pressure (PSnS) at 1373 K. Under optimal conditions, 90.10 wt% Sn and 94.90 wt% Zn can be extracted in the dust, which can be further processed into higher value-added Sn concentrate. Compared with current beneficiation process, the recovery ratio of SnO2 increased by 20 %. More importantly, MgSn(OH)6 can be efficiently recovered. This is of great significance for sustainable metallurgy of Sn.

Fabrication and magnetic properties of pulse electrodeposited FeSn nanowire arrays

When it comes to fabricating efficient nanomaterials for magnetic recording media and spintronic devices, Fe-based nanowires (NWs) containing nonmagnetic elements can represent themselves as one of ideal candidates. Here, a pulse electrodeposition method in porous anodic alumina membranes is employed to fabricate Fe100-xSnx (2 ≤ x ≤ 68) NW arrays with a diameter of about 35 nm. During the NW fabrication, Sn electrolyte concentration (CSn) and off-time (Toff) between pulses change in the range from 0.0025 to 0.02 M and 0–75 ms, respectively. As a general trend, magnetic properties including coercivity and squareness values decrease with increasing the Sn content. Meanwhile, first-order reversal curve diagrams show single domain and pseudo-single domain states of the FeSn NWs, depending on the Sn content in the structure dominated by Fe or FeSn alloy crystal phase. Magnetostatic interactions and coercive field distributions are also observed to significantly change by varying CSn and Toff, providing magnetically tunable FeSn NW arrays induced by the nonmagnetic element addition.

Ultrasound-assisted extraction of Sn from tinplate scraps by alkaline leaching: Novel acoustoelectric synergy effect underlying intensifying mechanism

Clean and fast extraction of tin from the surface of tinplate scraps is of great significance for the efficient utilization of waste resources. However, the dense tin layer causes the low efficiency of conventional leaching process. To improve Sn leaching efficiency, the ultrasound technique was adopted to extract Sn from tinplate scraps by alkaline leaching in this study. In the NaOH-H2O2 leaching system, metallic tin and alloyed tin in Fe-Sn alloy located on the surface of tinplate scraps can be oxidized and transferred to soluble Na2SnO3, while the iron in Fe-Sn alloy was oxidized to oxides which were chemically inert in alkaline solution. The differences in chemical solubility of Sn and Fe, and solubleness of stannate and iron oxides gave rise to the selective separation of Sn from the tinplate scraps. The effects of the leaching parameters on the Sn leaching behaviors in conventional and ultrasound-assisted leaching processes were compared. The conventional leaching temperature and time were significantly reduced during the ultrasound-assisted leaching process. Almost all of Sn can be extracted after conventional leaching at 1 mol/L NaOH, temperature of 80 ℃ and time of 60 min, however the same Sn leaching effect can be achieved by ultrasound-assisted leaching at 60 ℃ for 30 min with ultrasound power of 60% (360 W). Sn leaching kinetics based on the plate model demonstrated the reaction rate constant of the ultrasound-assisted leaching was 70% higher than that of the conventional leaching. A novel acoustoelectric synergy effect underlying intensifying mechanism by ultrasound irradiation was proposed in this study. Eventually, this work provided a rapid and clean tin extraction method from tinplate scraps via the ultrasound-assisted alkaline leaching treatment.

Achievement of Ultralow Elastic Modulus through Optimization of Phase Stability and Recrystallization Texture in Ti–Nb–Fe–Sn Alloys

Ti–Nb–Fe–Sn alloys with relatively low Nb content, located near the phase boundary of (β + ω)/β, are designed on the basis of electron‐to‐atom (e/a) ratio, d‐electron alloy design concept, and Mo equivalent (Moeq) aiming at low Young's modulus comparable to human bone. The effect of Sn content and Nb content on the microstructure and the mechanical properties is investigated in Ti–5Nb–3Fe–(0–6)Sn (at%) and Ti–(3–9)Nb–3Fe–4Sn (at%) alloys. The composition dependence of Young's modulus and tensile strength of Ti–Nb–Fe–Sn alloys is analyzed in terms of the phase stability, ω phase, and recrystallization texture. Both Nb and Sn are effective in suppressing the athermal ω phase and stabilizing the β phase. The recrystallization texture is strongly influenced by the content of Sn and Nb. A strong {110}β<001>β Goss texture is formed in the Ti–5Nb–3Fe–(2–4)Sn and Ti–(3–5)Nb–3Fe–4Sn alloys. The Ti–5Nb–3Fe–4Sn alloy exhibits an exceptionally low Young's modulus of 30 GPa due to the combined effects of low stability of the β phase, a small amount of ω phase, and a strong Goss texture.

Thermodynamic modeling of the Fe-Sn system including an experimental re-assessment of the liquid miscibility gap

The usage of low-grade ferrous scrap has increased over decades to decrease CO2 emissions and to produce steel products at a low cost. A serious problem in melting post-consumer scrap material is the accumulation of tramp elements, e.g., Cu and Sn, in the liquid steel. These tramp elements are difficult to remove during conventional steelmaking processes. Sn is considered as one of the most harmful tramp elements because, together with Cu, it sometimes induces the liquid metal embrittlement in high-temperature ferrous processing, e.g., continuous casting and hot rolling. Furthermore, the chemical interaction between Fe and Sn plays an important role in the Sn smelting process. The raw material used in the Sn smelting process is SnO2 (cassiterite), in which Fe3O4 is a gangue in the Sn ore. In the process, the reduction of Fe3O4 is unavoidable, which results in forming a Fe-Sn alloy (hardhead). The recirculation of the hardhead decreases the furnace capacity and increases the energy consumption in the smelting. The need to efficiently recover Sn from secondary resources is therefore inevitable. The CALculation of PHAse Diagrams (CALPHAD) approach helps to predict the equilibrium state of the multicomponent system. Previously reported studies of the Fe-Sn system show inconsistencies in the calculations and the experimental results. Mainly the miscibility gap in the liquid phase was under debate, as experimental data of the phase boundary are scattered. Experimental study and re-optimization of model parameters were carried out with emphasis on the correct shape of the miscibility gap. Three different experimental techniques were employed: differential scanning calorimetry, electromagnetic levitation, and contact angle measurement. The present thermodynamic model has higher accuracy in predicting the solubility of Sn in the body-centered cubic (bcc), compared to previous assessments. This is achieved by re-evaluating the Gibbs energies of the FeSn and FeSn2 compounds and the peritectic reaction related to Fe5Sn3. Also, the inconsistencies related to the miscibility gap around XSn = 0.31-0.81 were resolved. The database developed in the present study can contribute to the development of a large CALPHAD database containing tramp elements.

Tin Removal from Tin-Bearing Iron Concentrate with a Roasting in an Atmosphere of SO2 and CO

The tin could be volatilized and removed effectively from the tin-bearing iron concentrate while roasted in an atmosphere of SO2 and CO. The reduction of SO2 by CO occurred in preference to the SnO2 and Fe3O4, and the generated S2 could sulfurize the SnO2 to an evaporable SnS, which resulted in the tin volatilization. However, the Fe3O4 could be sulfurized simultaneously, and a phase of iron sulfide was formed, retaining in the roasted iron concentrate. It decreased the quality of the iron concentrate. In addition, the formation of Sn-Fe alloy was accelerated as the roasting temperature exceeded 1100 °C, which decreased the Sn removal ratio. An appropriate SO2 partial pressure and roasting temperature should be controlled. Under the condition of the roasting temperature of 1050 °C, SO2 partial pressure of 0.003, CO partial pressure of 0.85, and residence time of 60 min, the tin content in the roasted iron concentrate was decreased to 0.032 wt.% and the sulfur residual content was only 0.062 wt.%, which meets the standard of iron concentrate for BF ironmaking.

Co-roasting of tin tailings and waste cathode carbon for the recovery of Sn, Zn, Pb and F

Tin tailings are a common type of solid waste containing Sn, Pb, Zn, Fe, Si, and Ca. Currently, most tin tailings are being stored in piles or landfills. This study proposes the co-roasting of tin tailings and waste cathode carbon(WCC) to allow for proper waste disposal. The result shows that ZnCO3 was transformed into ZnS-FeS eutectic, which restricted the formation Fe-Sn alloy. Simultaneous separations and recoveries of Sn, Pb, and Zn from tin tailings was realized under strong reducing atmosphere. Under optimal experimental conditions, the Sn, Pb and Zn recovery ratios were 95%, 98% and 95%, respectively. Additionally, NaF in the WCC was mainly transformed to CaF2, and 98% F can be solidified. The F, Pb, Zn, As, and Cu leached contents of the roasted residue in the toxicity characteristic leaching procedure(TCLP) met the national allowable emission standards. Iron phase could be reduced to high value metallic Fe, and its contents reached 88.75 wt% after magnetic separation. The tailings of magnetic separation can be reused as building materials, and CaF2 can enhance material properties, minimizing environmental risks. In industrial production, WCC can act as a fuel and reducant, which can significantly reduce tin tailings processing costs.

Effect of resveratrol on Sn-Fe alloy electrodeposition

• We verified that resveratrol has better antioxidant properties than other stabilizers. • Resveratrol was successfully introduced to bath for improving the stability. • We confirmed the optimal concentration of resveratrol in the bath. The Sn-Fe alloy coating is a potential choice for decorative coatings and electronic products because of its excellent performance. However, oxidation of the bath is likely to occur in the process of use, which limits the production of electrodeposition of Sn-Fe alloy. Resveratrol has excellent antioxidant capacity and is considered as a non-polluting natural antioxidant. However, the understanding of using of resveratrol as stabilizer for electroplating solution in the field of electrodeposition is limited. In this study, resveratrol, hydroquinone and TBHQ are selected as the stabilizers of the electroplating bath to conduct comparative experiments for measuring the stability effect of resveratrol. The antioxidant capacities of three stabilizers are compared by means of the natural oxidation experiment, H 2 O 2 accelerated oxidation experiment and electrochemical testing. The natural oxidation experiment and H 2 O 2 accelerated oxidation experiment confirm that the antioxidant effect of resveratrol is higher than hydroquinone and TBHQ. To determine the optimal concentration of resveratrol in the electroplating solution, EIS and salt spray test were conducted. These results show that appropriate resveratrol can improve the corrosion resistance of the coating, but excessive resveratrol is detrimental to corrosion resistance. Therefore, the optimal concentration of resveratrol in the electroplating solution is 1.0 g/L.

Peculiarity of magnetocaloric and magnetoresistance effects in Ni–Mn–Sn–Fe alloy with successive metamagnetic structural transitions

Magnetocaloric and magnetoresistance properties originated from a metamagnetic structural transition were investigated in a Fe-doped Ni46.8Mn38.1Sn11.6Fe3.5 alloy. After annealing, the alloy exhibited the intermartensite phase that contributed to the multiple abrupt magnetization and resistivity changes during heating process of martensite transformation. As a result, three successive magnetic entropy change ΔSM peaks of 10.7, 14.5 and 9.7 J/kg·K at temperatures 275, 279 and 285 K respectively were observed, which was responsible for a wide working temperature span ΔTFWHM of 273–287 K and thus a large effective refrigeration capacity RCeff of 98.1 J/kg under 5.0 T. At the same time, a large negative magnetoresistance MR (e.g. over 26.7% at 275 K) was also revealed during heating process under 5.0 T. Such multi-functional magnetocaloric and magnetoresistance effects render Ni–Mn–Sn–Fe alloys promising working materials for magnetic refrigerants, information storage and thermal magnetoelectricity conversions.

Microstructure and mechanical properties evolution during thermomechanical processing of a Ti–Nb–Zr–Ta–Sn–Fe alloy

During the last decades, Titanium-based alloys have shown a suitable combination of strength, ductility, corrosion and biocompatibility properties, that marks them as suitable implant materials for biomedical applications. In this study, a Ti–30Nb–12Zr–5Ta–2Sn-1.25Fe (wt%) alloy was produced by melting in a cold crucible induction in levitation furnace, deformed by cold rolling, with a total deformation degree (thickness reduction) of 50%, in five equal steps, and solution treated at 850 °C, with progressive treatment durations, from 5min to 20min, in 5min increments. The initial microstructure is homogenous, consisting of equiaxed β-Ti phase grains showing an average grain size close to 135 μm. The applied cold deformation induces changes in the microstructure, which shows the presence of deformation bands, twins, dislocation bands and of an increased crystal defects density and residual strain–stress fields. Also, an increase in strength and decrease in ductility properties are noticed due to the strain hardening. The applied solution treatment leads to the regeneration of the microstructure, the obtained microstructure showing homogeneous equiaxed β-Ti phase grains, with an average grain size between 60 μm and 80 μm, depending on the solution treatment duration. Also, a decrease in strength and increase in ductility properties are noticed due to the lowering of the crystal defects density, remanent strain–stress fields and an increase of the average grain size.

Enhancing the catalytic activity and CO2 chemisorption ability of the perovskite cathode for soild oxide electrolysis cell through in situ Fe-Sn alloy nanoparticles

Herein, the Sn-doped perovskite oxide Sr1.95Fe1.4Sn0.1Mo0.5O6-δ (SFSnM), which exhibited in situ exsolved Fe-Sn alloy nanoparticles and controllable phase transformation, was synthesized to catalyze the reduction of CO2 through A-site deficiency regulation. The in situ exsolved Fe-Sn alloy nanoparticles were uniformly distributed on the surface of the SFSnM substrate after reduction, which significantly enhanced the catalytic activity and CO2 adsorption capacity of the SFSnM cathode. Moreover, a single cell with an FeSn@SFSnM cathode exhibited excellent CO2 electrolysis performance, achieving a current density of 3.269 A cm−2 and an Rp value of 0.145 Ω cm2 at 800 °C and 1.8 V. Additionally, no significant performance attenuation was observed during a long-term stability test (200 h), indicating the good stability of FeSn@SFSnM cathode. Overall, these results demonstrated that the designed FeSn@SFSnM cathode shows great potential for high-performance solid oxide electrolysis cells (SOECs).

Analysis of the effect of the liquid phase separation on the formation of microstructure in the Sn Fe and Al Fe Sn alloys

In the present paper, the wide miscibility gap in liquid phase in the Al-Fe-Sn system is well defined for the first time. A large miscibility gap extends from the SnFe side and dramatically extends upon addition of Al. The evolution of the microstructure during solidification was investigated experimentally in the entire concentration range in binary SnFe and ternary Al-Fe-Sn systems using SEM/EDS, XRD and DTA/DSC techniques. The existence of Fe3Sn phase in the SnFe system was confirmed. It was found that the FeAl2 phase in the ternary system participates in equilibrium with the liquid phase contrary to the binary AlFe system where it is formed in a solid state. All the binary phases do not demonstrate any essential solubility of the third component. Liquidus and solidus projections, melting diagram, isothermal section at 850 °C, vertical sections on isoconcentrates 10, 20 and 35 at.% Sn and a Scheil reaction scheme for the Al-Fe-Sn system covering the whole concentration range were constructed for the first time.

Microstructure, mechanical properties, and cytotoxicity of low Young’s modulus Ti–Nb–Fe–Sn alloys

Microstructure, mechanical properties, and cytotoxicity of low Young’s modulus Ti–Nb–Fe–Sn alloys

Metastable dual-phase Ti–Nb–Sn–Zr and Ti–Nb–Sn–Fe alloys with high strength-to-modulus ratio

Conventional dual-phase titanium (Ti) alloy exhibits high strength and toughness, but the high elastic modulus makes it unsuitable for biomedical implants. In this study, two novel metastable dual-phase (α"+β) Ti–Nb–Sn–(Zr/Fe) systems have been developed using [Mo]eq theory. The dual-phase α"+β structure contributed to the alloys’ characteristics of high strength and low elastic modulus. The bending strengths of Ti–(16−22)Nb–8Sn–(5−8)Zr and Ti–(17−19)Nb–8Sn–(0.5–1.5)Fe alloys (1023–1190 MPa and 960–1308 MPa, respectively) were obviously higher than that of Ti–25 Nb–8Sn (962 MPa). Among them, both Ti–18Nb–8Sn–7Zr and Ti–19Nb–8Sn–0.5Fe with dual phase had lower elastic moduli (50.4 and 50.5 GPa, respectively) than Ti–25Nb–8Sn (52 GPa), which can avoid the stress shielding effect after implantation. Ti–18Nb–8Sn–7Zr and Ti–19Nb–8Sn–0.5Fe alloys exhibited greater bending strength-to-modulus ratios (20.3 and 19.0, respectively) than those of c.p. Ti (7.1) and Ti–25Nb–8Sn (18.5). Both dual-phase Ti–18Nb–8Sn–7Zr and Ti–19Nb–8Sn–0.5Fe with low elastic moduli and high strength-to-modulus ratios are promising candidates for bio-implant applications.

Study the effect of symmetrical voltage of electrodeposition and annealing ‎temperature on magnetic properties of Fe-Sn alloy nanowires

In this research, the Fe-Sn alloy nanowires were made by AC electrodeposition method in anodic ‎aluminum oxide (AAO). The effect of different symmetrical voltages of electrodeposition (17.5-32.5 V) ‎and annealing temperature on magnetic and structural properties of Fe-Sn nanowires were investigated. ‎The magnetic properties, morphology, element composition of materials and crystal structure of the ‎nanowires were studied by AGFM, SEM, EDX and XRD, respectively. The results showed that, coercivity ‎field (Hc) and square ratio (Sq) increases by increasing deposition voltage and also, crystallinity of the ‎nanowires and resulting their crystalline magnetic anisotropy increased, but deposition percentage of Sn ‎to Fe reduced. The Hc and Sq of prepared nanowires were increased by annealing due to increases in their ‎crystalline structure and crystalline magnetic anisotropy. The most variation in Hc and Sq were achieved ‎for prepared nanowires at 30 V.‎

Grain Size Effect of the γ Phase Precipitation on Martensitic Transformation and Mechanical Properties of Ni-Mn-Sn-Fe Heusler Alloys.

Isothermal annealing of a eutectic dual phase Ni–Mn–Sn–Fe alloy was carried out to encourage grain growth and investigate the effects of grain size of the γ phase on the martensitic transformation behaviour and mechanical properties of the alloy. It is found that with the increase of the annealing time, the grain size and volume fraction of the γ phase both increased with the annealing time predominantly by the inter-diffusion of Fe and Sn elements between the γ phase and the Heusler matrix. The isothermal anneals resulted in the decrease of the e/a ratio and suppression of the martensitic transformation of the matrix phase. The fine γ phase microstructure with an average grain size of 0.31 μm showed higher fracture strength and ductility values by 28% and 77% compared to the coarse-grained counterpart with an average grain size of 3.31 μm. The fine dual phase microstructure shows a quasi-linear superelasticity of 4.2% and very small stress hysteresis during cyclic loading, while the coarse dual phase counterpart presents degraded superelasticity of 2.6% and large stress hysteresis. These findings indicate that grain size refinement of the γ phase is an effective approach in improving the mechanical and transformation properties of dual phase Heusler alloys.

Tin recovery from a low-grade tin middling with high Si content and low Fe content by reduction—sulfurization roasting with anthracite coal

A new method for separating and recovering tin from a low-grade tin middling with high Si content and low Fe content by roasting with anthracite coal was researched by studying the reaction mechanism and performing an industrial test, in which the Sn was sulfurized into SnS(g) and then collected using a dust collector. The Fe-Sn alloy may be formed at roasting temperatures above 950°C, and like the roasting temperature increases, the Sn content and Sn activity in this Fe-Sn alloy decrease. Also, more FeS can be formed at higher temperatures and then the formation of FeO-FeS with a low melting point is promoted, which results in more serious sintering of this low-grade tin middling. And from the thermodynamics and kinetics points of view, the volatilization of the Sn decreases at extremely high roasting temperatures. The results of the industrial test carried out in a coal-fired rotary kiln show that the Sn volatilization rate reaches 89.7% and the Sn is concentrated in the collected dust at a high level, indicating that the Sn can be effectively extracted and recovered from the low-grade tin middling with a high Si content and low Fe content through a reduction—sulfurization roasting process.