Liquid Tin Research Articles

Joining of Copper Plates by Unusual Wetting with Liquid Tin and Tin–Lead Solder on “Surface Fine Crevice Structure”

Joining of Copper Plates by Unusual Wetting with Liquid Tin and Tin–Lead Solder on “Surface Fine Crevice Structure”

High-brightness laser-induced EUV source based on tin plasma with an unlimited lifetime of electrodes

Characteristics of a source of laser-induced radiation in the extreme ultraviolet (EUV) range, obtained in a discharge between two jets of liquid tin, are investigated. The possibility of designing a high-brightness EUV source on this basis for employing in mask inspection techniques in projection EUV lithography is demonstrated. The average efficiency of converting the electric energy to radiation in the spectral range of is approximately sr with the size of emitting plasma . The possibility of producing a EUV source with a brightness of about is demonstrated.

Surface tension and long range corrections of cylindrical interfaces.

The calculation of the surface tension of curved interfaces has been deeply investigated from molecular simulation during this last past decade. Recently, the thermodynamic Test-Area (TA) approach has been extended to the calculation of surface tension of curved interfaces. In the case of the cylindrical vapour-liquid interfaces of water and Lennard-Jones fluids, it was shown that the surface tension was independent of the curvature of the interface. In addition, the surface tension of the cylindrical interface is higher than that of the planar interface. Molecular simulations of cylindrical interfaces have been so far performed (i) by using a shifted potential, (ii) by means of large cutoff without periodic boundary conditions, or (iii) by ignoring the long range corrections to the surface tension due to the difficulty to estimate them. Indeed, unlike the planar interfaces there are no available operational expressions to consider the tail corrections to the surface tension of cylindrical interfaces. We propose here to develop the long range corrections of the surface tension for cylindrical interfaces by using the non-exponential TA (TA2) method. We also extend the formulation of the Mecke-Winkelmann corrections initially developed for planar surfaces to cylindrical interfaces. We complete this study by the calculation of the surface tension of cylindrical surfaces of liquid tin and copper using the embedded atom model potentials.

Effect of water on tin penetration in subsurface layer of glass

Since the float glass produced by oxy-fuel combustion technology contains higher structural water than that produced by air-fuel combustion, ‘bloom phenomenon’ is a serious issue. In order to study the effect of water in the glass on the tin penetration, glass with different water contents was lab-prepared and the glass forming process was simulated by floating glass melt on the surface of liquid tin. Water content in glass was determined by Fourier translation infrared. The penetrated amount of tin and its distribution in glass were analysed by X-ray fluorescence spectrometer and Electron Probe MicroAnalyer (wavelength Dispersive Spectrometer). The results showed that the water content in glass strongly depended on the moisture concentration in the melting atmosphere. Meanwhile, it was found that both the penetrated amount of tin and the penetration depth in glass were related to the water content in glass.

A compact centrifugal pump for transmitting molten metals and other liquids with an operating temperature of up to 380°C

A centrifugal pump for transmitting molten metals and other liquids with a working temperature as high as 380°C is described. The pump ensures a head pressure of up to 9 atm and a flow rate of up to 1 m3/h. A rotary torque is transmitted from the electric motor to the turbine of the pump by means of the alternatingpole magnetic coupling. The compactness of the design is ensured by a vacuum gap between the “hot” inner and “cold” outer half-couplings. The pump is applied in high-power X-ray and extreme ultraviolet sources for forming liquid tin jets used as updated electrodes (in sources based on a discharge plasma) or a updated target (in sources based on a laser plasma), where it ensures velocities of tin jets of up to 15 m/s.

ChemInform Abstract: Synthesis and Surface Chemistry of High Quality Wurtzite and Kesterite Cu2ZnSnS4 Nanocrystals Using Tin(II) 2‐Ethylhexanoate as a New Tin Source.

AbstractA new synthesis of the title nanocrystals is reported, in which solid and difficult to dissolve precursors of tin are replaced by liquid tin(II) 2‐ethylhexanoate.

Mechanistic Considerations of Liquid Metal Anode SOFCs Fueled with Hydrogen

Much interest is currently being devoted to solid oxide fuel cells (SOFCs) with liquid metal anodes.1–3 Technological developments of SOFCs operating with various molten anodes have been reviewed recently.4 Novel approaches to understanding this molten electrode system include the development of the Rotating Electrolyte Disc (RED)5. This technique offers the prospect of allowing the determination of parameters controlling mass transport of dissolved species in the melt. Development of the RED technique and of molten anode SOFCs requires careful probing of the fundamentals of operation. As such, a stepping stone to operation on direct solid fuel is the use of a simpler system such as the anodic oxidation of hydrogen at a liquid tin anode / YSZ interface. This paper discusses the dissolution of hydrogen and its electrochemical oxidation at a liquid tin anode / YSZ interface. The approach is also suitable for use with other gaseous reactants (e.g. CO). An electrochemical model is developed, used for analysis and validated against experimental data. An important factor, w ’ , is proposed, which is a measure of the balance between the rate of dissolution of hydrogen in liquid tin and its rate of removal via anodic oxidation to water, which is of technological significance when designing such reactors. To avoid any complexity associated with formation of metal oxide, including blockage of the electrolyte (a typical adverse effect) during operation of liquid tin anode SOFCs6, the cell was operated in a narrow potential window in which tin electrode was effectively “inert” and could not interfere in any electrochemical reactions (Figure 1). The lower limit of operating potential was set by the Sn-SnO2 couple and the upper limit by generation of electronic carriers in YSZ. Hydrogen with partial pressures ranging from 8 to 26 kPa was supplied to the liquid tin anode and anodically oxidised at the liquid tin / YSZ interface on the inner surface of a 8YSZ tube by application of a potential of -0.90 V vs. air electrode (RE) at 780 °C. Platinum counter and reference electrodes were coated on the outer side of YSZ tube. Electrical connection to the working electrode was achieved using a glassy carbon rod immersed within the liquid tin inside the YSZ tube. The anodic current was monitored with time while p(H2) was increased step-wise from zero to 8, 15 and 26 kPa (Figure 2a) and reduced back from 26 kPa to zero (Figure 2b). The observed direct proportionality between steady currents and p(H2) was evident (for the range of flow rates studied) and served as an indicative effect that was considered in the modelling. Experimental investigations were first performed to assess the effect of hydrogen partial pressure in terms of current generation and dynamics associated with changes in hydrogen concentration in the melt. These results were then used in support of an analytical modelling analysis. Determination of the w ’ parameter, as well as solubility limits of hydrogen in liquid tin during the operation, are also considered.

Synthesis and crystal growth of microcrystals of the cubic and new orthorhombic polymorphs of (NH4)2SnCl6

Ammonium hexachlorostannate single crystals were obtained from gas phase of decomposition products of SnCl4·5NH3 formed in reaction of liquid tin(IV) chloride with gaseous ammonia. The crystals of both cubic (NH4)2SnCl6, obtained hitherto only by crystallization from solution, and of the formerly unknown orthorhombic polymorph were deposited on inner walls of the quartz reactor used. The values of the structure refinement factor R obtained is 0.01. Unit cell parameters of the new orthorhombic form of ammonium hexachlorostannate were determined and are reported.

Effect of Nickel on Density and Surface Tension of Liquid Tin

Density and surface tension for Sn1-xNix(x = 0; 0,05; 0,1) have been measured by means of sessile drop method. Temperature dependences of these parameters as well as influence of Ni-atoms on density and surface tension were analyzed. It is shown that chemical ordering is one of the most important factor, determining surface properties and density.

Corrosion of steels in molten gallium (Ga), tin (Sn) and tin lithium alloy (Sn–20Li)

The compatibility of steels in liquid gallium (Ga), tin (Sn) and tin lithium alloy (Sn–20Li) was investigated by means of static corrosion tests. The corrosion tests were performed for reduced activation ferritic martensitic steel JLF-1 (JOYO-HEAT, Fe–9Cr–2W–0.1C) and austenitic steel SUS316 (Fe–18Cr–12Ni–2Mo). The test temperature was 873K, and the exposure time was 250 and 750h. The corrosion of these steels in liquid Ga, Sn and Sn–20Li alloy was commonly caused by the formation of a reaction layer and the dissolution of the steel elements into the melts. The reaction layer formed in liquid Ga was identified as Fe3Ga from the results of metallurgical analysis and the phase diagram. The growth rate of the reaction layer on the JLF-1 steel showed a parabolic rate law, and this trend indicated that the corrosion could be controlled by the diffusion process through the layer. The reaction layer formed in liquid Sn and Sn–20Li was identified as FeSn. The growth rate had a linear function with exposure time. The corrosion in Sn and Sn–20Li could be controlled by the interface reaction on the layer. The growth rate of the layer formed in liquid Sn and Sn–20Li was much slower than that in liquid Ga. The weight change of the JLF-1 specimen immersed in Sn–20Li for 750h was measured after the removal of the adherent Sn–20Li in a Li pool. The weight loss was 1.42×103g/m3, and this value was 1500 times larger than that tested in liquid lead lithium alloy (Pb–17Li) at the same conditions in the previous studies.

Mechanistic Considerations of Liquid Metal Anode SOFCs Fueled with Hydrogen

Liquid metal anode (LMA) solid oxide fuel cells (SOFCs) are a promising type of high temperature fuel cell suitable for the direct oxidation of gaseous or solid fuels in the bulk of liquid metal. Depending upon the operating conditions, they can be run in four different modes. In the present study, concerning the mechanism of reaction and species transport in LMA SOFCs, the oxidation of fuel (H2) in the bulk of a liquid tin anode has been investigated via operation in so-called Chemical - Electrochemical mode (CE mode) and Electrochemical - Chemical (EC) modes. Theoretical considerations to be applied in the modelling of the obtained experimental data regarding the dissolution of hydrogen in a molten tin anode and its oxidation with oxygen dissolved in liquid tin followed by anodic oxygen injection in mode CE are also discussed.

Thermal cracking of methane in a liquid metal bubble column reactor: Experiments and kinetic analysis

This study is in the context of hydrogen production by thermal decomposition of methane for the purpose of reducing the CO2 footprint of hydrogen production processes. Experimental studies on methane conversion in a liquid tin bath were carried out and compared with existing kinetic data from other studies in order to identify a suitable reaction rate for the measured conversion. Experiments were conducted using a liquid tin bubble column stainless steel tube reactor with an inner diameter of 35.9 mm and a total length of 1150 mm, comprising a tin filling height of either 1000 mm or 600 mm. Methane gas was injected at flow rates in the range of 5–200 mln/min from the bottom of the reactor maintained at temperatures between 700 °C and 950 °C via a single hole orifice of diameter 1 mm. In general, methane conversion increased with increasing reactor temperatures and decreasing flow rates. The developed thermo-chemical model fitted well with the experimental data obtained during runs with the blank reactor. However, experimental data obtained at 900 °C at very low flow rates (≤25 mln/min – very high residence times and high conversion rates) appear to be much lower than predicted by the model. Further experiments and an improved model are required to understand the process and develop this technology further ahead.

On the wetting of aluminum and copper surface by tin-lead melts

The polytherms of the contact angles of tin-lead melts on aluminum and copper surfaces are determined, and the wettability thresholds are found. The wetting mechanism of aluminum and copper with liquid tin with small additions of lead is refined based on studies of the surface morphology.

Melting point depression of tin nanoparticles embedded in a stable alpha-alumina matrix fabricated by ball milling

Ball milling of SnO2 and Al powders creates Sn nanoparticles embedded in a stable α-Al2O3 phase through a displacement reaction. The production of stable α-Al2O3 phase indicates that sufficient thermal energy was supplied by ball milling to activate the displacement reaction. Melting points of Sn nanoparticles were observed to decrease with reducing particle size. The interfacial energy of solid tin particle-matrix was computed to be larger than liquid tin particle-matrix one. This is due to the formation of incoherent Sn-Al2O3 interfaces by ball milling.

Mechanistic Studies of Liquid Metal Anode SOFCs: I. Oxidation of Hydrogen in Chemical - Electrochemical Mode

Liquid metal anode (LMA) solid oxide fuel cells (SOFCs) are a promising type of high temperature fuel cell suitable for the direct oxidation of gaseous or solid fuel. Depending upon the operating conditions they can be run in four different modes. In this first of a series of studies concerning the mechanism of reaction and species transport in LMA SOFCs, the oxidation of hydrogen fuel in a liquid tin anode has been investigated. An electrochemical model is developed based upon fast dissolution of hydrogen in a molten tin anode, slow, rate-determining homogeneous reaction of hydrogen with oxygen dissolved in the liquid tin, followed by anodic oxygen injection under diffusion control to replace the oxygen removed by reaction (so-called Chemical - Electrochemical mode or CE mode). Experimentally-generated data are used to validate the model. The model has introduced a new key parameter, , which takes a value between zero and unity; its value is determined by geometric and convective factors in the cell as well as the partial pressure of the supplied hydrogen fuel. Current output of the cell is proportional to the value of .

Electrochemically depositing titanium(iii) ions at liquid tin in a NaCl–KCl melt

The electrochemical behavior of titanium ions at a liquid tin cathode has been investigated in a NaCl–KCl melt at 1023 K.

Performance evaluation of a liquid tin anode solid oxide fuel cell operating under hydrogen, argon and coal

A liquid tin anode solid oxide fuel cell is constructed and investigated under different operating conditions. Electrochemical Impedance Spectroscopy (EIS) is used to reflect the effect of fuel feed as the EIS spectra changes significantly on switching the fuel from argon to hydrogen. A cathode symmetric cell is used to separate the impedance from the two electrodes, and the results indicate that a major contribution to the charge-transfer and mass-transfer impedance arises from the anode. The OCP of 0.841 V for the cell operating under argon as a metal-air battery indicates the formation of a SnO2 layer at the electrolyte/anode interface. The increase in the OCP to 1.1 V for the hydrogen fueled cell shows that H2 reduces the SnO2 film effectively. The effective diffusion coefficients are calculated using the Warburg element in the equivalent circuit model for the experimental EIS data, and the values of 1.9 10−3 cm2 s−1 at 700 °C, 2.3 10−3 cm2 s−1 at 800 °C and 3.5 10−3 cm2 s−1 at 900 °C indicate the system was influenced by diffusion of hydrogen in the system. Further, the performance degradation over time is attributed to the irreversible conversion of Sn to SnO2 resulting from galvanic polarization.

Direct methanol utilization in intermediate temperature liquid-tin anode solid oxide fuel cells

Direct utilization of methanol in liquid tin anode solid oxide fuel cells has been experimentally demonstrated at 1023K. A Cu and SDC modified Sn anode solid oxide fuel cell had a maximum power density of 259.2mW/cm2 during operation on methanol. Carbon deposition was not observed in the Raman spectra of the post-test anodes. Electrochemical impedance spectroscopy indicated that gas conversion resistance increased when using methanol instead of hydrogen. The micro-channel architecture of the electrode mitigated the increase. Scanning electron microscopy images showed that addition of Cu and Sn improved wetting of Sn on YSZ and reduced anode polarization resistance. The anode gases were analyzed by mass spectroscopy and a mechanism for electrochemical oxidation of methanol has been proposed.

Electrodeposition of Liquid Metals from Molten Salts

Many important metals are being produced by electrolysis in molten salts (aluminium, sodium, rare earths and other reactive metals). Also industrial electrorefining of aluminium takes place in a molten salt electrolyte. Current efficiency for metal deposition, specific energy consumption and environmental issues are important topics for considering the success of such processes. A wide range of electrolytes including molten salts can be used to electrowin reactive metals. New electrochemical processes are proposed for recycling of metals in molten salts.Controlled laboratory experiments were carried out to study electrolytic deposition of the liquid metals aluminium, magnesium, lead, indium and tin from molten salt electrolytes. An important feature is the fact that metals are soluble in molten salts. The excess electrons associated with the dissolved metal are in some cases responsible for the presence of electronic conduction in mixtures of molten salts and dissolved metals. In other cases the metal dissolves under the formation of a subvalent species. Diffusion and charge transfer kinetics related to metal deposition processes in molten salts were studied by using electrochemical techniques.

Stability of dendrite growth during directional solidification in the presence of a non-axial thermal field

The liquid–metal-cooling (LMC) directional-solidification process offers refinement of dendritic structure due to the increased cooling rate from enhanced heat extraction. However, under some conditions in the LMC process substantial lateral heat extraction occurs that leads to a change in dendrite morphology, resulting in grain nucleation or lateral growth – the formation of long secondary dendrite arms overgrowing favorably aligned primary dendrites. The conditions under which lateral growth occurs during solidification of alloys CMSX-486 and René-N4 have been studied experimentally and via solidification modeling. Solidification experiments have been conducted in a LMC furnace that utilizes liquid tin as the cooling medium and a floating ceramic baffle. A mold geometry was designed to evaluate a range of thermal conditions during solidification and assess the tendency for lateral growth. Correlations between dendritic structure, solidification-front curvature, solidification rate and thermal gradients have been analyzed. A criterion for predicting the onset of lateral growth based on the inclination of the solidification front at the casting surface is demonstrated.