Addition Of Sn Research Articles

The effect of addition of Sn to copper on hot compressive deformation mechanisms, microstructural evolution and processing maps

The high-temperature compressive deformation behavior of a Cu-10wt.% Sn solid solution alloy was studied in the temperature range of 843–993K and in the strain rate range of 10−3 – 10s−1 and the relationships among the flow stress, strain rate and temperature were determined. Based on the data obtained from the compression tests, the deformation mechanism was identified, and the processing maps were constructed. The Cu-10Sn alloy exhibited solute drag creep at low strain rates and high temperatures and power law breakdown (PLB) at high strain rates and low temperatures. In the processing maps, above the temperature of 933K, the alloy did not show flow instability up to a high strain rate of 10s−1 and showed high power dissipation efficiencies (31–35%) even at the very high strain rate of 10s−1. Furthermore, at 993K, the fraction of dynamically recrystallized grains after compressive deformation was as high as 0.83 at 10s−1. These results indicate that the Cu-10Sn alloy exhibits a significantly better hot workability and a higher quality of post-deformation microstructures compared to the pure Cu where dislocation climb creep is the main deformation mechanism. Continuous dynamic recrystallization occurred at 843K, while discontinuous dynamic recrystallization occurred at 993K. Comparison of the current results with the previous work on the Cu-4.9Sn alloy indicates that the increase of Sn concentration in Cu matrix extends the regime of solute drag creep and delays the onset of PLB to a lower temperature and a higher strain rate.

Deuterium addition to liquid Li–Sn alloys: implications for plasma-facing applications

Liquid metals are being explored actively as candidates for plasma-facing components (PFCs) in fusion reactors. Recently, Li–Sn alloys have appeared as promising alternatives that could overcome some of the challenges faced by the well-studied liquid Li system, namely, a vapor pressure that limits the operating temperature and a high hydrogen isotope retention. However, only scarce data (experimental or theoretical) are available concerning the performance of Li–Sn alloys, specifically only for the compositions of Li30Sn70 and Li20Sn80, related to their bonding and retention of deuterium (D). Here, we present a comprehensive, first-principles molecular-dynamics study of static and dynamic properties of liquid Li30Sn70 at various D concentrations. We observe the formation of D2 gas bubbles for β in Li30Sn70Dβ greater than 22.5 along with Li segregation towards D2 bubbles. To understand the effect of Sn addition on D retention in Li–Sn alloys, we perform a thermodynamic evaluation of maximum D retention in Li-rich Li–Sn alloys. Overall, this work will provide useful data and guidance in the development of Li–Sn PFCs in fusion reactors.

Microstructure Evolution and Phase Transitions of the Annealed Cu–11%Al Alloy with Sn and Gd Additions

The effects of Sn or Gd additions on the microstructure and phases transitions of the Cu–11%Al alloy (composition in wt.) were studied by Vickers microhardness measurements as a function of quenching temperature, optical microscopy (OM), scanning electronic microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed that the addition of Sn stabilizes the $$ \beta $$ phases, whereas the addition of Gd modifies the alloy microstructure, but it does not significantly interfere on the phase transitions observed in the Cu–11%Al alloy.

First-principles modeling of the hydrogen evolution reaction and its application in electrochemical corrosion of Mg

By means of first-principles calculations, we have proposed an ab initio modeling to establish a formula between the hydrogen evolution rate and its overpotential of hydrogen evolution reaction (HER), relating with three different rate determining mechanisms, when Volmer reaction, Tafel reaction and Heyrowsky reaction are the rate determining steps of the entire reaction, respectively. Within this modeling, the free energy (ΔGH*) of the adsorbed hydrogen atom and the concentration of hydrogen ions in the solution have been correlated to the exchange current density. The hydrogen evolution modeling has been validated by available experimental results. Furthermore, by combining the previously proposed first-principles modeling of the anodic dissolution and this modeling of the HER in the electrochemical corrosion, the polarization curves of the 18 crystallographic surfaces of pure Mg have been theoretically derived. It has been found that in a neutral solution (pH=7) the corrosion current densities (icorr) of the 18 crystallographic surfaces range from 10−3.477 to 10−0.455 A/cm2 and their corresponding corrosion potentials (Ecorr) range from −1.36 to −0.892 VSHE, respectively. The base (0001) surface exhibits a lower corrosion rate of 10−3.345 A/cm2, whereas the crystal (213¯0) surface has a fast corrosion rate of 10−0.455A/cm2. The calculations even reveal that except for Ag, all the other alloying elements considered here accelerate the rates of the cathodic HER. In agreement with theoretical results, the experimentally measured polarization curves of the Mg-1Zn and Mg-2Sn alloys verify that both Zn and Sn additions accelerate the rate of the HER of Mg.

Impact of Sn4+ Substitution at Cr3+ Sites on Thermoelectric and Electronic Properties of p-Type Delafossite CuCrO2

The effects of Sn4+ substitution at Cr3+ sites on the thermoelectric and electronic properties of p-type delafossite CuCrO2 have been studied. CuCr1−xSnxO2 (x = 0.01, 0.03) samples were prepared via conventional solid-state reaction. The Seebeck coefficient results confirmed that all the samples exhibited p-type conduction. X-ray photoelectron spectroscopy verified the presence of Sn4+ ions and the appearance of mixed-state Cr3+/Cr2+ ions. The experimental results revealed that addition of Sn impacted the electrical conductivity due to the mixed Cu1+/Cu2+ states while the Seebeck coefficient was affected by the mixed Cr3+/Sn4+ states. The electrical conductivity was governed by the polaron hopping mechanism, and the large Seebeck coefficient was controlled by the spin and orbital degeneracy of the mixed Cr3+/Sn4+ ions. The electrical conductivity activation energy values were 0.410 eV and 0.407 eV while the thermal activation energy values were 0.208 eV and 0.160 eV, for x = 0.01 and 0.03, respectively. The results confirm that Sn4+ substitution at Cr3+ sites impacted the Seebeck coefficient and electronic behavior of delafossite CuCrO2 oxide even for low dopant levels of x = 0.01 and 0.03, resulting in p-type conduction and optically conducting materials.

Fabrication, characterization, and photocatalytic activity of anatase/rutile/SnO2 nanocomposites

Anatase/rutile/SnO2 nanocomposites have been synthesized through a sol–gel method. The crystal structure, surface morphology, chemical valence, specific surface area, and optical property of the samples were investigated by XRD, Raman, SEM, TEM, HRTEM, XPS, BET, DRS, and PL analyses. The addition of Sn promotes the phase transition from anatase to rutile. The formed anatase/rutile/SnO2 three-phase coexistence structure is beneficial to the separation of photogenerated pairs and the decrease of band gap. The photocatalytic behavior of photocatalysts was studied via the photodegradation of MB solution under xenon lamp irradiation. With the increase of Sn concentration, the photocatalytic performance of TiO2/SnO2 is improved, and all TiO2/SnO2 photocatalytic activities are higher than pure TiO2. 32%Sn–TiO2 (32%ST) exhibits the highest photocatalytic activity and the MB has been completely photodegraded in 30 min.

Maintaining high saturation magnetic flux density and reducing coercivity of Fe-based amorphous alloys by addition of Sn

The effect of minor Sn on crystallization behavior, soft magnetic properties and corrosion resistance of Fe83B10-xC3Si3P1Snx (x = 0.25, 0.5 and 0.75) amorphous alloys was investigated. Sn added alloys exhibit excellent saturation magnetic flux density (Bs) of 1.63–1.72 T, low coercivity of 2.5–5.4 A/m and higher corrosion resistance. Furthermore, coercivity of as-spun alloys is lowered by Sn addition, and mechanisms behind the change of soft magnetic properties were discussed. The finding suggests that soft metal Sn may act as a stress reliever in as-spun alloys, leading to low coercivity while maintaining ductility. This theory was then confirmed in high Co content amorphous alloys with Bs of 1.75 T, in which case Sn addition causes significant reduction of coercivity but no decline of Bs. The present strategy of Sn addition may pave a new and universal way for Fe-based amorphous alloys to simultaneously obtain high Bs, lower Hc and high ductility.

Novel insight into dry sliding behavior of Cu-Pb-Sn in-situ composite with secondary phase in different morphology

The Cu-24Pb-xSn (wt%) (x = 0, 2, 4, 6) alloys with Pb-rich second-phase particles (SPPs) in different shapes show obviously differently mechanical and self-lubricating properties. The influence of the SPPs’ shape difference on the alloys’ mechanical and self-lubricating properties was revealed. Cu-24Pb alloy with continuously netty SPPs shows much more intensive stick-slip phenomenon during dry sliding than the other three alloys with independently rodlike SPPs. That is mainly due to insufficient lubrication resulted by the netty SPPs’ splitting matrix. With the SPPs transforming from netty to rodlike shape under the addition of Sn, the stick-slip phenomenon was notably weakened, which was proven to be related to the higher self-lubricating property of alloys with rodlike SPPs. Simultaneously, the simultaneous increase of ductility and tensile strength was observed in the Cu-24Pb-xSn alloys with increasing Sn content, which is because the netty SPPs’ splitting behavior will be weakened with them replaced by the rodlike SPPs.

Enhancing the bake-hardening responses of a pre-aged Al-Mg-Si alloy by trace Sn additions

Effects of additions of trace Sn on the bake-hardening responses of a pre-aged Al-0.85Mg-0.85Si (in wt%) alloy were investigated through mechanical tests, differential scanning calorimetry, electrical resistivity and transmission electron microscopy. Results indicate that trace Sn additions reduced the number density of pre-aging clusters by inhibiting the formation of unstable counterpart during pre-aging treatment, leading to low strength and high supersaturation of solute atoms. In a subsequent paint-bake treatment, the presence of highly supersaturated solute atoms and high concentrated free vacancies moderated the activation energy barrier of βʺ phase and thus kinetically accelerated the formation of βʺ. Consequently, the trace Sn additions enhanced the bake-hardening responses of the pre-aged alloys significantly. The Sn-containing pre-aged Al-Mg-Si alloys with low strength and great bake-hardening responses hold promising potential for automotive body skin applications.

Effect of Sn-addition on the properties of the biomedical Ti-17Nb-6Ta alloy.

The effect of Sn-addition (0, 1.5, and 3 Sn, at.%) to the biomedical Ti-17Nb-6Ta alloy has been investigated in this study. The three alloys were proved using XRD analysis to be β-type alloys. Microstructural analysis using optical microscope showed martensite lathes in all alloys and proved that Sn addition stabilized β phase and suppresses the martensite formation during quenching. Micro-hardness results showed a slight increase with 1.5% Sn adding but superior addition of Sn with 3% at. has negligible effect on the hardness compared to Sn-free alloy. The compressive yield stress for the three alloys located between 400 to 500 MPa, and the stain values increased with the increasing of Sn percentages in the TNT alloy.

The Effect of Oxygen Addition on Microstructure and Mechanical Properties of Various Beta-Titanium Alloys

Simultaneously achieving high strength and low Young’s modulus is essential for implant materials due to the “stress-shielding effect”. In this work, the mechanical properties and microstructure of various beta-titanium alloys based on the Ti-Nb system with additions of Zr, Ta and Sn have been studied. Those alloys were prepared via the arc melting process. Thermo-mechanical processing (i.e., hot forging, solution treatment and cold swaging) has been performed. The alloys exhibited low Young’s modulus around 50 GPa (43 GPa was the lowest measured value) and tensile strength around 800 MPa. The tensile strength was increased via aging treatment (450°C/8 h) to 985 MPa while the modulus increased to 75 GPa. On the other hand the addition of 0.4 wt.% of oxygen seems to be more beneficial as the tensile strength reached values as high as 1225 MPa and simultaneously maintained low Young’s modulus (~ 62 GPa) and sufficient elongation (~ 8%).

Suppressing interfacial voids in Cu/In/Cu microbump with Sn and Cu addition

To overcome the reliability and manufacturing drawbacks in 3D-IC, such as warpage and low thermal budget, low temperature solder alloys are increasingly studied. Although Indium-rich solder has a beneficial low melting point of 156 °C, the formation of interfacial voids after bonding has raised concerns for reliability. By introducing Cu and Sn, the solder retained low melting points and the interfacial voids in microbumps were significantly reduced. The melting point of Cu-Sn-In alloys were measured to ensure that there is no additional phase transformation at higher temperature. In addition, the interfacial IMCs phases were characterized.

Fischer-Tropsch Synthesis: Cd, In and Sn Effects on a 15%Co/Al2O3 Catalyst

The effects of 1% of Cd, In and Sn additives on the physicochemical properties and Fischer-Tropsch synthesis (FTS) performance of a 15% Co/Al2O3 catalyst were investigated. The fresh and spent catalysts were characterized by BET, temperature programmed reduction (TPR), H2-chemisorption, NH3 temperature programmed desorption (TPD), X-ray absorption near edge spectroscopy (XANES), and X ray diffraction (XRD). The catalysts were tested in a 1 L continuously stirred tank reactor (CSTR) at 220 °C, 2.2 MPa, H2/CO = 2.1 and 20–55% CO conversion. Addition of 1% of Cd or In enhanced the reduction degree of 15%Co/Al2O3 by ~20%, while addition of 1% Sn slightly hindered it. All three additives adversely impacted Co dispersion by 22–32% by increasing apparent Co cluster size based on the H2-chemisorption measurements. However, the decreased Co active site density resulting from the additives did not result in a corresponding activity loss; instead, the additives decreased the activity of the Co catalysts to a much greater extent than expected, i.e., 82–93%. The additional detrimental effect on catalyst activity likely indicates that the Cd, In and Sn additives migrated to and covered active sites during reaction and/or provided an electronic effect. XANES results showed that oxides of the additives were present during the reaction, but that a fraction of metal was also likely present based on the TPR and reaction testing results. This is in contrast to typical promoters that become metallic at or below ~350 °C, such as noble metal promoters (e.g., Pt, Ru) and Group 11 promoters (e.g., Ag, Au) on Co catalysts in earlier studies. In the current work, all three additives remarkably increased CH4 and CO2 selectivities and decreased C5+ selectivity, with the Sn and In additives having a greater effect. Interestingly, the Cd, In, or Sn additives were found to influence hydrogenation and isomerization activities. At a similar conversion level (i.e., in the range of 40–50%), the additives significantly increased 2-C4 olefin content from 3.8 to 10.6% and n-C4 paraffin from 50 to 61% accompanied by decreases in 1-C4 olefin content from 48 to 30%. The Sn contributed the greatest impact on the secondary reactions of 1-olefins, followed by the In and Cd. NH3-TPD results suggest enhanced acid sites on cobalt catalysts resulting from the additives, which likely explains the change in selectivities for the different catalysts.

Effect of Sn and Cu addition on the precipitation and hardening behavior of Al-1.0Mg-0.6Si alloy

The effects of Cu and/or Sn addition on the age hardening response and microstructure of the Al-1.0Mg-0.6Si alloy were investigated using hardness test, tensile test, differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and 3-D atom probe (3DAP). The results indicate that natural aging (NA) of the Al-1.0Mg-0.6Si alloy was suppressed by the addition of Sn, particularly by the addition of both Cu and Sn. The addition of Sn alone enhanced the hardening response and peak hardness of the Al-1.0Mg-0.6Si alloy artificially aged immediately after quenching, whereas the hardening response and peak hardness of those artificially aged after two weeks NA decreased, which are related to the slowing down of the precipitation kinetics. Regardless of whether the alloys were previously natural aged, the alloy with the joint addition of Cu and Sn displayed higher artificial aging (AA) hardening response and peak hardness than those of alloys with the addition of only Cu or Sn. This is related to the accelerated precipitation and high number density of the precipitates. The advantage of the joint addition of Cu and Sn is the delay of NA and the acceleration of the subsequent AA.

Mechanical and corrosion behaviour of hydroxyapatite reinforced Mg-Sn alloy composite by squeeze casting for biomedical applications

Abstract Magnesium alloys have gained increasing attention for biomedical applications due to their biocompatibility and the biodegradability. Hydroxyapatite (HA) is known to be a highly bioactive because of its similar chemical and crystallographic structures to bone. Therefore, HA is believed to be a potential ceramic material for the fabrication of Mg based composites, to combine the advantages of both Mg and HA. But, in general, the composites known to be more susceptible to corrosion attack than the matrix alloy. Hence, in the present work, Sn is used as an alloying element to evaluate its effect on mechanical as well as corrosion properties of Mg/HA composites. Mg with 5 wt% HA and Mg-1 wt% Sn-5 wt% HA composites were prepared separately by stir assisted squeeze casting route. The phase analysis and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS) respectively. Mechanical properties were evaluated by conducting the compression and micro hardness tests. Corrosion properties of as-cast composites were studied by linear polarization, Tafel and electrochemical impedance spectroscopy (EIS) techniques. The results of both XRD and SEM-EDS revealed that the main constitutional phases of as-cast Mg/HA composites were α-Mg and HA whereas, in Mg-Sn/HA composites, the phase Mg2Sn was observed along with fine distribution of HA particles. In both the cases, no interfacial reactions observed. The yield strength, ultimate compression strength and hardness were found to be increased with the addition of Sn in Mg/HA composites. Furthermore, the addition of Sn also played an important role in increasing the corrosion resistance of the Mg/HA composites which was attributed the refinement of grain size and the formation of Mg2Sn phase along the grain boundaries. Hence, it was concluded that the addition of Sn improves both mechanical and corrosion properties of Mg/HA composites.

Preparation and electrochemical properties of Al-based composite coating electrode with Ti4O7 ceramic interlayer for electrowinning of nonferrous metals

Electrode materials with an Al-based coating and a Ti4O7 ceramic interlayer were prepared by plasma spraying to obtain improved electrochemical properties. RuO2–TiO2 coatings doped with Sn, Ta and Ir, or La were prepared by thermal decomposition. The results indicate that good bonding between Al and Ti4O7 was obtained by plasma spraying. The dopants affected the electrochemical performance by changing the surface morphology of the active coatings. The addition of Sn not only improved the electrocatalytic activity in the chlorine evolution reaction but also inhibited the electrocatalytic activity in the oxygen evolution reaction. The electric potential distribution on the surface of the electrode materials with an Al-based coating and a Ti4O7 ceramic interlayer was more uniform than that of a Ti/RuO2–TiO2 anode. The results of electrowinning tests revealed that an Al/Ti4O7/RuO2–TiO2–SnO2 anode exhibited the best anodic performance with lower energy consumption, a longer accelerated lifetime, more deposition of Co as a product, and greater efficiency.

Effects of 1WT.% Ti, In, and Sn Additions on the Microstructure, Mechanical and Corrosion Properties of the As-Cast and Hot-Rolled AM60 Magnesium Alloys

We study the influence of 1 wt.% Ti, In and Sn additions on the microstructure, mechanical properties and corrosion resistance of the as-cast and hot-rolled AM60 magnesium alloys. The analysis of microstructure was performed by using optical and scanning electron microscopes The phase composition of the alloys and grain sizes are analyzed. We also determine the ultimate strength, yield limit, relative elongation, and corrosion resistance of the alloys. The efficiency of alloying of AM60 alloy with titanium and tin (for the improvement of the mechanical characteristics) and with indium (for the improvement of corrosion resistance) is demonstrated.

(Invited) Engineering Hematite Photoelectrodes Interfaces for Sunlight Water Oxidation Reaction

Here, pristine and Sn-hematite electrodes were obtained with two different morphologies (columnar, CN, and ellipsoid (EN) nanostructure) by low-cost aqueous chemical method. The following step was the addition at the Sn-hematite surface of a spinel cocatalyst that was also synthesized via chemical method. Sn-hematite-cocatalyst (Ni2FeOx) electrodes were submitted to additional thermal treatment under nitrogen atmosphere to activate the material surface. The pristine hematite electrode showed considerable enhancement on photocurrent density J, in comparison with previous work in our group for both method from a range of ~ 30 µA.cm-2up to 0.2 mA.cm-2 and 1.0 mA.cm-2to 2.0 mA.cm-2at 1.23 VRHE, for CN and EN photoelectrodes respectively. Such improvement has been mainly attributed to a better uniformity of the films and an improved interfacial adherence of the hematite thin film to the TCO provoked primarily by the deposition layer control. Likewise, the addition of Sn+4during hematite photoelectrode prepared enhance the photocurrent response with a pronounced alteration on the onset of the photocurrent curve, moving towards anodic direction from ~0.8 VRHE for pristine photoelectrode to ~0.95 VRHE for Sn-hematite photoelectrode. The final step was the addition of a cocatalyst, such as Ni2FeOX, over the Sn-hematite that leads to a significant shift on the onset potential toward the cathodic direction without drop photocurrent performance as usually observed. In summary, the synergy of Sn+4and Ni2FeOXaddition enables us to promote a shift on the onset towards a lower potential and enhancing the photocurrent density. The authors gratefully acknowledge support from FAPESP (Grant 2017/11986-5) and Shell and the strategic importance of the support given by ANP (Brazil’s National Oil, Natural Gas and Biofuels Agency) through the R&D levy regulation

Influence of Sn on the age hardening behavior of Al–Mg–Si alloys at different temperatures

Addition of minute amounts of Sn to Al–Mg–Si alloys is known to have a pronounced effect on their age hardening characteristics. In this study, the influence of Sn addition on the ageing behavior of lean and concentrated alloys at five different temperatures was studied. Hardness, positron annihilation lifetime spectroscopy and transmission electron microscopy measurements complemented by differential scanning calorimetry yield information that allow one to assess the microscopic mechanisms that govern ageing. It is found that Sn slows down the ageing kinetics at 100 °C and 140 °C but accelerates the kinetics and enhances the hardening response at 210 °C and 250 °C. At the standard artificial ageing temperature of 180 °C, the effect of Sn on ageing varies depending on the alloy composition. The observed different ageing kinetics can be explained by the different vacancy behaviors in the presence of Sn. Moreover, the activation energy analysis reveals that the ageing process in Sn-added alloys is controlled by both the separation of Sn-vacancy complexes and the migration of solute-vacancy complexes.

Influence of Zn and Sn on the Precipitation Behavior of New Al-Mg-Si Alloys.

In this study, we demonstrate how Zn and Sn influence hardening behavior and cluster formation during pre-aging and paint bake treatment in Al–Mg–Si alloys via hardness tests, tensile tests, and atom probe tomography. Compared to the standard alloy, the Sn-modified variant shows reduced cluster size and yield strength in the pre-aged condition. During the paint bake cycle, the clusters start to grow very fast and the alloy exhibits the highest strength increment. This behavior is attributed to the high vacancy binding energy of Sn. Adding Zn increases the formation kinetics and the size of Mg–Si co-clusters, generating higher yield strength values for both the pre-aged and paint baked conditions. Simultaneous addition of Zn and Sn creates a synergistic effect and produces an alloy that exhibits moderate strength (and good formability) in the pre-aged condition and accelerated hardening behavior during the paint bake cycle.