Sn Solid Solution Research Articles

Synthesis and tribological characterization over a wide temperature range for A-site elements doping in Ti3AlC2

This work investigates the possibility of doping Si and Sn solid solution components (separate/simultaneous incorporation) into Ti3AlC2 to provide desired mechanical properties and tribological self-adaptability over a broad temperature range. The specimens are sintered at 1450 °C for 2 h in a vacuum environment with a pressure of 30 MPa. The phase composition, mechanical properties and tribological characteristics sliding against Al2O3 counter balls over a wide temperature range from room temperature to 800 °C are investigated. The results demonstrate considerable lattice distortion together with significant solid solution strengthening effects in quinary solid solutions. The friction coefficients of the four solid solutions are discovered to be temperature-sensitive from the distinguished variation tendencies in the wide temperature range. The wear rates exhibit a comparable tendency with test temperature that the values are two orders of magnitude lower at 600−800 °C than those at RT−400 °C. The noticeably lubricant tribofilm is responsible for the decreased wear rate at elevated temperatures. The distinct tribological behaviors of the quaternary and quinary solid solutions are ascribed to the characteristics of the self-generated oxides.

The tin content of lead inclusions in ancient tin-bronze artifacts: a time-dependent process?

In antiquity, Pb was a common element added in the production of large bronze artifacts, especially large statues, to impart fluidity to the casting process. As Pb does not form a solid solution with pure Cu or with the Sn–Cu alloy phases, it is normally observed in the metal matrix as globular droplets embedded within or in interstitial positions among the crystals of Sn-bronze (normally the α phase) as the last crystallizing phase during the cooling process of the Cu–Sn–Pb ternary melt. The disequilibrium Sn content of the Pb droplets has recently been suggested as a viable parameter to detect modern materials [Shilstein, Berner, Feldman, Shalev & Rosenberg (2019). STAR Sci. Tech. Archaeol. Res. 5, 29–35]. The application assumes a time-dependent process, with a timescale of hundreds of years, estimated on the basis of the diffusion coefficient of Sn in Pb over a length of a few micrometres [Oberschmidt, Kim & Gupta (1982). J. Appl. Phys. 53, 5672–5677]. Therefore, Pb inclusions in recent Sn-bronze artifacts are actually a metastable solid solution of Pb–Sn containing ∼3% atomic Sn. In contrast, in ancient artifacts, unmixing processes and diffusion of Sn from the micro- and nano-inclusions of Pb to the matrix occur, resulting in the Pb inclusions containing a substantially lower or negligible amount of Sn. The Sn content in the Pb inclusions relies on accurate measurement of the lattice parameter of the phase in the Pb–Sn solid solution, since for low Sn values it closely follows Vegard's law. Here, several new measurements on modern and ancient samples are presented and discussed in order to verify the applicability of the method to the detection of modern artwork pretending to be ancient.

Self‐lubricating effect of solid solution elements on tribological performance of Ti3AlC2 over a wide temperature range

AbstractThis study explores the feasibility of tribological self‐lubricating over a wide temperature range by doping Si and Sn solid solution components on the A‐sites of Ti3AlC2 to adapt to the severe circumstances. The specimens were sintered at 1450°C for 120 min under a pressure of 30 MPa in a vacuum environment, and their dry sliding tribological capabilities against Al2O3 at temperatures ranging from ambient temperature to 800°C were investigated using a rotational ball‐on‐disk tribo‐tester. The findings demonstrated a constantly decreased friction coefficient of Ti3Al0.8Si0.2Sn0.2C2 throughout the temperature range and admirable antifriction at higher temperatures where wear rates were 1–2 orders of magnitude lower than those at room temperature, which was superior to earlier reported Ti3AlC2. The predominant friction surface self‐adaptability mechanisms after solid solution treatment were determined to be tribo‐oxidation wear and tribo‐chemical reactions that played a vital role by examining the microstructural evolutions and tribo‐chemical phase composition on friction surfaces at various temperatures. The tribo‐oxidation‐induced generated lubricant film consisting of TiO2, Al2O3, SnO2 mixture oxide phases, and aluminosilicates was responsible for the decreased friction coefficient and wear rate.

First-principles calculations of structural and elastic properties of Sn solid solution, Cu6Sn5 and SnSb in tin-based bearing alloy

Tin-based bearing alloy has the microstructure characteristics of hard phases distributed on the soft solution matrix. The soft solution matrix provides lubrication and embeddability, and the hard phases provide carrying capacity. The design and development of high-performance alloys need to obtain the performance characteristics of the constituent phases. This paper studies the basic physical properties and mechanical properties, such as geometric structure optimization, cohesive energy, elastic constant, elastic modulus and structural stability of Sn solid solution, Cu6Sn5 and SnSb in tin-based bearing alloy by using the first-principles calculations method. Results show that the crystal structural stability relationship of the three compounds is SnSb > β-Sn > Cu6Sn5 by comparing specific cohesive energy. Cu6Sn5 crystal has the highest deformation resistance and stiffness, followed by SnSb and β-Sn. SnSb crystal has the best plasticity, followed by β-Sn and Cu6Sn5. β-Sn and SnSb are plastic materials, and Cu6Sn5 is brittle material. It is hoped that this paper can provide theoretical support for the subsequent micro-mechanism and micro-design of high-performance tin-based bearing alloy.

Effect of Sn addition on the low temperature shrinkage of Ni nanoparticles

In this study, in-situ formation of intermetallic compound (IMC) was proposed to reduce the sintering shrinkage mismatch between Ni electrode and dielectric material for multilayer ceramic capacitors (MLCCs). Tin (Sn) was selected as an alloying element and introduced in the form of SnCl2 into Ni nanopowder. The Sn precursor was decomposed at ∼450 °C and a cubic Ni3Sn intermetallic phase was formed at 500 °C, which was gradually transformed to a hexagonal Ni3Sn phase at 700 °C and thereafter thermally decomposed above 800 °C forming the Ni–Sn solid solution. The Sn addition shifted the shrinkage onset temperature of Ni electrode to a higher temperature by 300–400 °C and effectively retarded the low temperature densification through in-situ formation of Ni3Sn intermetallics by inhibiting the inter-diffusion between Ni nanoparticles. Furthermore, the sintered Sn added Ni (Ni–3Sn) electrode exhibited an electrical conductivity comparable to that of pure Ni electrode, demonstrating its suitability as an alternative electrode for MLCCs.

Porous lithiophilic Cu-Sn solid solution current collector for dendrite-free lithium metal batteries

Lithium metal batteries (LMBs) have high energy density but suffer from the formation of Li dendrites and unstable solid electrolyte interface. Herein, a three-dimensional porous Cu-Sn solid solution was designed as current collector for LMBs and was fabricated through the combination of vapor phase alloying with subsequent vapor phase dealloying. The effect of the Sn addition on electrochemical performances and Li plating/stripping behaviors was investigated using in-situ X-ray diffraction, ex-situ scanning electron microscopy, as well as density functional theory calculations. As benchmarked with porous Cu (3D-Cu), the addition of lithiophilic Sn can efficiently improve the Li plating/stripping performance, especially for the 1.5 at.% Sn addition (3D-Cu98.5Sn1.5). The 3D-Cu98.5Sn1.5 current collector maintains coulombic efficiency of 95 % up to 200 cycles at 1 mA cm−2. Moreover, the existence of Sn in solid solution exhibits a much lower binding energy (-3.223 eV) and nucleation overpotential (28.9 mV) compared with those of 3D-Cu, indicating that the metallic Li is extremely susceptible to nucleation and growth on the surface. Additionally, the gas evolution scenarios were probed by on-line differential electrochemical mass spectrometry. Our findings show that the 3D-Cu98.5Sn1.5 current collector effectively enhances the uniformity of Li plating and suppresses the generation of dendrites in LMBs.

Insights into the Sensing Mechanism of a Metal-Oxide Solid Solution via Operando Diffuse Reflectance Infrared Fourier Transform Spectroscopy.

Recently, the influence of Nb addition in the oxide solid solution of Sn and Ti was investigated with regard to the morphological, structural and electrical properties for the production of chemoresistive gas sensors. (Sn,Ti,Nb)xO2-based sensors showed promising features for ethanol monitoring in commercial or industrial settings characterized by frequent variation in relative humidity. Indeed, the three-metal solid solution highlighted a higher response level vs. ethanol than the most widely used SnO2 and a remarkably low effect of relative humidity on the film resistance. Nevertheless, lack of knowledge still persists on the mechanisms of gas reaction occurring at the surface of these nanostructures. In this work, operando Diffuse Reflectance Infrared Fourier Transform spectroscopy was used on SnO2- and on (Sn,Ti,Nb)xO2-based sensors to combine the investigations on the transduction function, i.e., the read-out of the device activity, with the investigations on the receptor function, i.e., compositional characterization of the active sensing element in real time and under operating conditions. The sensors performance was explained by probing the interaction of H2O and ethanol molecules with the material surface sites. This information is fundamental for fine-tuning of material characteristics for any specific gas sensing applications.

Effects of trace amounts of Sn, Ca, and Cu on the electrochemical properties and discharge performance of Mg-2Zn-1Gd-0.5Zr as an anode for Mg-air battery

To explore the effect of microalloying on Mg-2Zn-1Gd-0.5Zr (wt.%) (ZG21), the discharge characteristics of ZG21 and ZG21-0.2X (X = Sn, Ca, Cu) were investigated comparatively. Sn solid solution into α-Mg, reduces galvanic corrosion and chunk effect, and greatly improves the discharge efficiency of ZG21. The efficiency of ZG21-0.2Sn are obtained at 20 mA cm−2 with 63.5%. Ca addition makes the open circuit potential more negative and forms Ca2Mg6Zn3 phase to further promote the activity, and because of the loose and easy to exfoliate products, in summary, ZG21-0.2Ca discharge voltage is higher which can reach 1.268 V at 10 mA cm−2. The addition of Cu to form the MgZnCu phase increases the activity and also reduces the grain size, which should be beneficial to the discharge performance, but still the discharge performance is bad due to severe hydrogen evolution. The addition of Sn and Ca provides new ideas and options composition design of Mg-air battery anodes.

Differential effects of Sn and Si solutes on the microstructure and properties of Cu–Ni–Al alloys with coherent L12-γ′ phases

In order to solve the discontinuous precipitation of nano-spherical γ′ coherent precipitates strengthened Cu–Ni–Al alloys and explore the influence mechanism of trace elements on the microstructure and properties. Herein, the Si and Sn, with same main group but showing different elemental interaction, was selected as the fourth element, and series of alloy composition were designed and prepared in a wide Cu content, and the effect of Si or Sn addition on microstructure, properties at room temperature and thermal stability are investigated. The results demonstrate that Si is completely dissolved into γ and γ′ phase, but a little of Sn solid solution into γ′ phase. The two adding elements can accelerate the precipitation of γ′ phases, suppress the grain boundaries discontinuous precipitation and provide dual-nanostructure strengthening effect, which enhance the hardness and conductivity, and Si exhibits more preferable effect. The thermodynamic calculation and the work function results indicate that the addition of Sn would induce the descending thermal stability of γ and γ′ phase, but Si is beneficial to the improvement of thermal stability of γ and γ′ phase. Compared to Sn, Si is more suitable to be a candidate for the multi-component design of Cu–Ni–Al alloys.

Flexible stretchable low-energy X-ray (30–80 keV) radiation shielding material: Low-melting-point Ga1In1Sn7Bi1 alloy/thermoplastic polyurethane composite

A highly flexible stretchable thermoplastic polyurethane (TPU) composite loaded with a low-melting-point Ga1In1Sn7Bi1 multiprincipal element alloy (LMPEA) was prepared, and its radiation shielding performance was evaluated. The fluid characteristic of LMPEA and the flexibility of TPU enable good interface compatibility. Ga1In1Sn7Bi1 LMPEA consists of two eutectic structures, and the liquid gallium-rich phases are distributed at the boundary of the InBi intermetallic compound and Sn solid solution. In the low-photon energy range of 30–80 keV, LMPEA has a theoretical specific lead equivalent of 0.803 mmPb/mm and a theoretical weight reduction of 17.27% compared with lead. To evaluate the photon attenuation capability for the LMPEA/TPU composites, the Phy-X procedure and Monte Carlo simulations were used to determine the shielding parameters, such as the mass attenuation coefficient, linear attenuation coefficient, half-value layer, tenth-value layer, mean free path, effective atomic number, and fast neutron removal cross section. The attenuation performance test of X-ray protective materials measured the actual lead equivalent. At the same thickness, the LMPEA/TPU composite (66.667, 50.000 wt% LMPEA loading) has a higher measured lead equivalent than the in-service medical shielding materials, which meets the lead equivalent requirements of X-ray protective clothing. LMPEA/TPU composites are nontoxic, lightweight, and have excellent low-energy X-ray shielding ability, offering great potential for application in medical wearable materials.

Design of a metal-oxide solid solution for selective detection of ethanol with marginal influence by humidity

Emerging nanotechnologies improved solid-state sensors design and capabilities and enabled the use of semiconducting metal oxides-based gas sensors for new and increasingly demanding applications. Among them, ethanol monitoring is of great interest because it is an important chemical raw material widely used in chemical industry, medicine, paint and cosmetics. Water vapour is the most common interferent during operating conditions, affecting the baseline stability of sensors, and reducing their sensitivity and accuracy. In this work, a strategy based on the formation of stoichiometric solid solutions of Sn, Ti and Nb oxides have been sought to address humidity dependence of sensor signals and to enhance the sensing response vs. ethanol. Powders were synthesised through sol-gel technique, by keeping the Sn:Ti ratio constant at the optimal value for ethanol detection with different Nb concentrations (1.5, 3.5 and 5 at%), and thermally treated at 650 °C and 850 °C. Such solid solutions exploited the good sensitivity of SnO2 towards most analytes and the low cross-sensitivity of TiO2 to humidity. Nb was added to lower the film resistance and to prevent grains coalescence at temperatures required for the formation of the solid solutions and the anatase-to-rutile phase transition. The results show that the niobium concentration and the heating treatment of powders are fundamental parameters to optimise the sensing features of the film towards ethanol monitoring applications and to lower the influence of humidity on its performance.

Fe-based sintered matrix for diamond tools: microstructure, mechanical performance and crack initiation and propagation characteristics

To design Fe-Cu-Sn-Ni metal binders for diamond tools and optimize the performance of binders, Fe-based binders were prepared by hot-press sintering method using Fe powder, Cu powder, Sn powder and Ni powder as the raw materials. The phase constitution, microstructure, mechanical properties and crack formation were evaluated. Results showed that Fe-based matrixes are composed of Cu3Sn intermetallic compounds and several solid solutions, such as α-Fe, γ(Fe,Ni), and Cu13.7Sn. The relative high Sn content can increase the hardness of the sintered bulk samples and significantly reduce the bending strength. With the increase of Ni content, the hardness increases gradually, while the bending strength increases firstly and then decreases. The cracks initiate from brittle Cu3Sn intermetallic phases and quickly propagate in the brittle phases or along the interface between Cu3Sn intermetallic compounds and γ(Fe,Ni) phases. The propagation of crack can be impeded by Cu13.7Sn solid solution.

Effects of various second phase ratios and contents on microstructure and mechanical properties of eutectic Sn58Bi alloy

A distinctive low melting point heterostructure alloy (LMH) Sn-Bi-Cu-Zn-Ag-Sb was prepared by introducing different ratios and contents of second phase into the eutectic Sn58Bi alloy (SBE). Rapid solidification results in a dispersion of Cu5Zn8, Ag3Sn, and SbSn precipitated phases in Sn53Bi3Cu3Zn2Ag2Sb (LMH32). Besides, the nano-sized η'-Cu6Sn5 and Ag3Sn phases were also observed in the alloy matrix. During solidification, the Cu5Zn8 and Ag3Sn phases are used as the heterogeneous nucleation matrix of the Sn and Bi phases, which significantly refines the eutectic structure and leads to fine-grained strengthening. And the formation of Sn(Sb) solid solution phase leads to solid solution strengthening. The significant mechanical incompatibility between the matrix and the second phases of the LMHs produces a higher back stress hardening effect. The coupling effect of multiple strengthening mechanisms causes the ultimate tensile strength (UTS) of LMH32 reaches 102 MPa, higher 88.9% than that of SBE, and the elongation reaches 12.8%, but the melting point does not change significantly.

Design of a Metal-Oxide Solid Solution for Sub-ppm H2 Detection.

Hydrogen is largely adopted in industrial processes and is one of the leading options for storing renewable energy. Due to its high explosivity, detection of H2 has become essential for safety in industries, storage, and transportation. This work aims to design a sensing film for high-sensitivity H2 detection. Chemoresistive gas sensors have extensively been studied for H2 monitoring due to their good sensitivity and low cost. However, further research and development are still needed for a reliable H2 detection at sub-ppm concentrations. Metal-oxide solid solutions represent a valuable approach for tuning the sensing properties by modifying their composition, morphology, and structure. The work started from a solid solution of Sn and Ti oxides, which is known to exhibit high sensitivity toward H2. Such a solid solution was empowered by the addition of Nb, which—according to earlier studies on titania films—was expected to inhibit grain growth at high temperatures, to reduce the film resistance and to impact the sensor selectivity and sensitivity. Powders were synthesized through the sol–gel technique by keeping the Sn–Ti ratio constant at the optimal value for H2 detection with different Nb concentrations (1.5–5 atom %). Such solid solutions were thermally treated at 650 and 850 °C. The sensor based on the solid solution calcined at 650 °C and with the lowest content of Nb exhibited an extremely high sensitivity toward H2, paving the way for H2 ppb detection. For comparison, the response to 50 ppm of H2 was increased 6 times vs SnO2 and twice that of (Sn,Ti)xO2.

A novel approach to dissimilar joining of AA7075 to AZ31B by friction stir soldering using Sn intermediate layer

ABSTRACT The dissimilar joining of 7075 to AZ31 by the friction stir soldering (FSS) process using a Sn interlayer was performed for the first time. The most appropriate microstructure with the highest shear strength was obtained by the one-pass FSS process via a 120 μm-thick intermediate layer. In the optimum situation, the 7075/solder interface was covered with an uninterrupted wavy layer of Sn solid solution, whereas the AZ31/Solder interface was covered with a thin intermetallic region (IMC) consisting of fine-Mg2Sn intermetallics distributed in an Mg2Sn + βSn eutectic matrix. The thickness of the IMC region increased with the decreasing thickness of the intermediate layer and/or the increasing FSS passes, leading to the deterioration of the joint strength. No Al-Mg intermetallics were detected on either the retreated or the advanced side of the one-pass joints; however, isolated Islands and a continuous network of Al-Mg intermetallics were identified at the advanced and retreated sides of the three-pass joints, respectively. In comparison with the advanced side, the retreated side contained a thinner tin-rich solid solution and a thicker IMC region. Moreover, the probability of crack formation or creation of brittle Al-Mg intermetallics on the retreated side was more than those on the advanced side.

Improvement of thermoelectric performance of SnTe-based solid solution by entropy engineering

SnTe is a good alternative to PbTe in the thermoelectric (TE) applications, in that it is a compound with no toxic element Pb. Besides, the compound SnTe has a relatively narrow bandgap (0.3–0.4 eV) and high Sn vacancy concentration (Sn<sub>v</sub>) as well. Accordingly, it gives a high carrier concentration (10<sup>21</sup> cm<sup>–3</sup>) at room temperature (RT), which is not favorable for thermoelectrics, therefore the regulation of both the electronic and phonon scattering mechanisms is strongly required. Up to date, there have been many approaches to improving its TE performance. The typical examples are those involving the valence band convergence, nanostructuring, substitutional and interstitial defects, and lattice softening, which are all practical and effective to improve the TE performance of SnTe. However, in this work the entropy is taken as an indicator to design the SnTe-based TE material with multicomponents and then optimize its TE performance. The detailed scheme involves the chemical composition design step by step. At first, SnTe alloys with 5% GaTe to form a solid solution Sn<sub>0.95</sub>Ge<sub>0.05</sub>Te, aiming to increase the solubility of the foreign species. The second step is to form another solid solution (Sn<sub>0.95</sub>Ge<sub>0.05</sub>Te)<sub>0.95</sub>(Ag<sub>2</sub>Se)<sub>0.05</sub> via the alloying Sn<sub>0.95</sub>Ge<sub>0.05</sub>Te with 5% Ag<sub>2</sub>Se. The purpose of this step is to reduce the p-type carrier concentration of the system, for the species Ag<sub>2</sub>Se is a typical n-type semiconductor. The last step is to form a series of solid solutions (Sn<sub>0.95–<i>x</i></sub>Ge<sub>0.05</sub>Bi<sub><i>x</i></sub>Te)<sub>0.95</sub>(Ag<sub>2</sub>Se)<sub>0.05</sub> by substituting different amounts of Bi on Sn in (Sn<sub>0.95</sub>Ge<sub>0.05</sub>Te)<sub>0.95</sub>(Ag<sub>2</sub>Se)<sub>0.05</sub>, to further enhance the configurational entropy (Δ<i>S</i>). Because of the above approaches, both the carrier concentration and thermal conductivity decrease while the highest TE figure of merit (<i>ZT</i>) increases from 0.22 for the pristine SnTe to ~0.8 for the alloy (Sn<sub>0.95–<i>x</i></sub>Ge<sub>0.05</sub>Bi<sub><i>x</i></sub>Te)<sub>0.95</sub>(Ag<sub>2</sub>Se)<sub>0.05</sub> (<i>x</i> = 0.075). This result proves that the entropy engineering is a practical way to improve the TE performance of SnTe, and at the same time it illustrates that it is very important to harmonize the entropy engineering with other electronic and phonon scattering mechanisms, in order to improve the TE performance of SnTe effectively.

Effects of Ga on Mechanical Properties and Microstructure of Cu–Sn–Ti Filler

To solve a series of problems of Cu–Sn–Ti fillers, Ga is added to the fillers to promote its mechanical properties and microstructure. The metallographic structure of Cu–Sn–Ti–xGa filler metals is detected by optical microscope. Energy dispersive spectroscopy (EDS) areal, X‐ray diffraction (XRD), and differential thermal analysis (DSC) are used to analyze the morphology and microstructure of the fillers. The results show that doped Ga can significantly decrease the melting point and increase mechanical properties of the fillers. The shear strength of the filler metals with 1% Ga content is 160% higher than without Ga. In addition, it is also observed that a small amount of Ga refine the CuSnTi filler metals matrix structure. The diffusion of elements in the filler metals is detected. Compared with Sn solid solution, Ga tends to form a solid solution with Cu. When the Ga content is 2 wt%, the shear strength of the filler metal decreases due to the appearance of coarse crystals at the bottom of the dimple. Through the study of the reaction layer between diamond and filler metal, it is found that Ga can increase the thickness of the interface reaction layer.

Reversible formation of metastable Sn-rich solid solution in SnO2-based anode for high-performance lithium storage

Tin dioxide (SnO2) has been considered as a promising anode for high-energy alkali-ion batteries due to its high theoretical specific capacity, but still plagued by the intrinsic issues of Sn coarsening and significant volume change during cycling. Herein, a stable Ti-SnO2 material is tactfully designed and constructed via one-step simple hydrothermal reaction for highly reversible lithium storage. Density functional theory (DFT) calculations and experimental results show that a metastable Sn-rich Sn(Ti) solid solution can be reversibly formed after multiple conversion reaction of the Ti-SnO2 and exhibits high recrystallization temperature of 509–589 K. Then, the solid solution formed by Ti atoms during the cycling leading to the enhanced inhibitory effect on the coarsening of Sn. Therefore, the Sn(Ti) solid solution can maintain a small grain size of 10 nm even after hundreds of cycles. Take an example, the Ti-SnO2 anode displays a stable long life with high Li discharge capacity of 705 mAh g−1 and 95.4% capacity retention (compared to the initial specific discharge capacity) after 700 cycles at 1 A g−1. This work provides a novel and versatile strategy to suppress the coarsening of Sn by inducing a metastable Sn-rich solid solution for all Sn-based compound anodes in alkali-ion batteries.

Porous Sn obtained by selective electrochemical dissolution of melt-spun Zn70Sn30 alloys with lithium and sodium storage properties

Zn70Sn30 alloys were prepared with two markedly different cooling rates of the melt - by conventional casting and by rapid solidification technique (melt spinning). As a result, alloys with different morphology and microstructure were obtained. Additionally, certain extension of the Sn(Zn) solid solution was also observed in the rapidly solidified material. After selective electrochemical dissolution of the as-cast alloys (nano)porous structures based on Sn were formed, as the structures obtained from the melt-spun alloys reveal significantly smaller pores as well as more homogeneous pores distribution on the alloy surface. An important result is also the mechanical stability of the porous structures prepared from melt-spun ribbons, which fact together with the appropriate composition makes them suitable for use as negative electrodes in ion batteries operating on the “alloying” principle. The porous electrodes obtained from the melt-spun Zn70Sn30 alloy deliver relatively high discharge capacities in Li- and Na-ion cells (around 440 and 210mAh/g, respectively). The cycling stability of the porous structures is better in the Na-ion cell. The initial results obtained from testing of Sn-based porous materials as electrodes in Na ion batteries are encouraging and deserve further optimization of the alloys composition, phase composition, microstructure and pores size.

Evolution of microstructure and physical properties of lead-free Sn–5Sb-Ag rapidly solidified solder alloys

Rapidly solidified (RS) binary Sn–5 wt.% Sb and ternary Sn–5 wt.% Sb– x wt.% Ag, x = 1, 3 and 5 solder alloys were prepared in form of ribbons using melt spinning technique (MS). X-ray diffractometer (XRD), scanning electron microscopy (SEM) attached with energy dispersive x-ray technique (EDX) and differential scanning calorimetry (DSC) were used to investigate the impacts of Ag contents on microstructures and properties of the binary Sn–5 wt.% Sb rapidly solidified alloy. XRD analysis confirmed the formation of an ultrafine microstructure of Ag3Sn intermetallic compound in addition to a supersaturated solid solution of Sn by Sb and Ag. Moreover, SEM and EDX analysis assigned the formation of SnSb intermetallic compound as well as the dissolution of Sb and Ag in β-Sn with maximum wt.% of 20.75 and 11.7 for Sn-5Sb and Sn-5Sb-5Ag ribbons, respectively. The melting point of the melt spun ribbons was lowered by 3.7 °C, 1.7 °C, 5.4 °C and 2.3 °C for the 0, 1, 3 and 5 Ag containing solder alloys as deduced by DSC. The rapidly solidified ribbons exhibit better Vickers hardness due to the microstructure refinements and the extension of solid solubilities of the alloying elements.