Pure Tin Research Articles

Influence of Element Lead (Pb) Content in Tin Plating on Tin Whisker Initiation/Growth

The implementation of the Restriction of Hazardous Substances (RoHS) European Union (EU) Directive in 2005 resulted in the introduction of pure tin as an acceptable surface finish for printed circuit boards and component terminations. A drawback of pure tin surface finishes is the potential to form tin whiskers. Tin whiskers are a metallurgical phenomenon that is associated with tin rich/pure tin materials and has been a topic of intense industry interest. The acceptance and usage of pure tin by the electronics industry component fabricators is understandable as the pure tin surface finishes are inexpensive, are simple plating systems to operate and have reasonable solderability characteristics. However, high performance/harsh environment electronics typically have product life cycles that are measured in decades and therefore are much more susceptible to the potential long term threat of tin whiskers. The GEIA-STD-0005-2 “Standard for Mitigating the Effects of Tin Whiskers in Aerospace and High Performance Electronic Systems” established the definition of the term “Pb-free tin” as : “Pb-free Tin is defined to be pure tin or any tin alloy with <3% lead (Pb) content by weight. A functional definition of “pure tin” was necessary so that the electronics industry could establish tin whisker risk protocols against a known acceptable target value in terms of soldering materials and processes. An investigation was conducted to determine the influence of 1% - 5% elemental lead (Pb) content in tin plating on tin whisker initiation and growth. The investigation results were used in the revision of the GEIA-STD-0005-2 “Standard for Mitigating the Effects of Tin Whiskers in Aerospace and High Performance Electronic Systems” specification technical discussions.

"Preparation of SnO2 thin films by doping with F-1 ions using chemical spray pyrolysis"

In this paper, the structural and optical properties of pure Tin Oxide and doped by Fluorine (F). Thin films were studied prepared by chemical spray pyrolysis on glass substrates at temperature 400oC. The nature of crystallization of the compounds was examined by using X-Ray diffraction technique which showed that the prepared thin films are polycrystalline structure, and the doping processes didn,t show any obvious differences on the crystalline structure of (SnO2). The DC conductivity measurements of the samples were performed by means of a two probe method. The activation energies were computed from the plots of σdc versus 1000/T. To obtain the optical parameters, the absorption and transmittance spectra were recorded in the wave length range 300-1100 nm, the energy gap of the direct and indirect allowed transition were calculated. The optical parameters such as absorption coefficient (α), refractive index (n), extinction coefficient (Ko), dielectric constant (ε'), and dielectric loss (tanδ), were also investigated.

Study the effect of alpha irradiation on the optical properties of pure and doped tin dioxide thin films prepared by spin coating

Chemical spin coating is used to prepare pure and indium doped thin films of tin dioxide. All pure and doped thin films have been annealed at a temperature of 500oC. The effects of indium doping and alpha irradiation on the optical properties were studied by recording spectra of transmittance and absorbance at wavelengths (250 - 1250) nm. We found that the transmittance decreases with increasing doping concentrations, while the absorbance increases with increasing doping concentrations, whereas the allowed direct optical band gap decreases with an increase of doping. The results of this study shows that alpha irradiation causes a decrease in the band gap values, and it also effect on the optical properties such as transmittance, absorption coefficient and reflectance.

Characterization of tin-plated steel

Tinplating on steel is a useful industrial process extensively used for food packaging. Cold-rolled annealed steel coated with tin gives the steel corrosion resistance property and a beautiful luster. Tinplating on steel is a complex process where rolled and annealed steel sheets are cleaned with acid to remove rust, grease, or oil from the surface. Pure tin is electrodeposited on this freshly prepared surface after the electrodeposition of tin on the steel strip; the surface becomes lustrous, the color of pure tin appears, and the finish is called matte. Very often, the flowing heat treatment is just about the tin melting point of 232°C–265°C. After electrodeposition, pure tin deposits on the steel surface; however, a chemical reaction between tin and iron occurs during the brightening treatment. This process results in iron–tin intermetallic formation; their orientation grain structure and orientation of substrate steel all have a synergistic effect on the final properties of tin-coated steel. In the present study, an attempt has been made to study this parameter in detail. A total of five commercially produced tin-plated steel have been selected for the present purpose, and both tin coating and substrate steel have been thoroughly characterized by optical microscopy, scanning electron microscopy, X-ray diffraction (XRD), and the crystallographic texture point of view; however, the best result has been discussed in this paper. The different phases of tin and the iron–tin compound have been identified using XRD, X-ray, and a texture goniometer that are used to find out the crystallographic texture observed in the presence of FeSn2, FeSn, and Sn in tin coating; the volume fraction of these phases is observed to vary from one sample to another. This variation may affect tinplating steel’s final property, which can be studied in the future work.

Propane gas-sensing properties of pure and Pd-doped tin oxide nanostructures

Propane gas-sensing properties of pure and Pd-doped tin oxide nanostructures

Highly Sensitive, Selective and Stable NO2 Gas Sensor Based on Porous Influenced SnO2 Bilayer Thin Films

In this work, an attempt has been made to fabricate SnO2 porous films using automated nebulizer spray pyrolysis technique with the influence of a porogen. Pure tin dioxide and porous tin dioxide (SnO2/SnO2) thin films were prepared from a precursor solution composed of SnCl2·2H2O and polyethylene glycol as a porogen. The structural, morphological, optical and gas sensing performance of the prepared thin films were characterized. The inclusion of porogen significantly improved the sensing property of porous SnO2 bilayer thin films and it was confirmed by structural, morphological and gas sensing performance studies. The optimized spray process parameter was determined finally in this work as SnO2 precursor strength of 0.2 M for porous SnO2 layer. Under this condition, the increased lattice constant, lattice defect and increased pores diameter were achieved, which exhibited good gas sensitivity and selectivity towards NO2 gas at 250 ºC. The response and recovery time is decreased as 50%, the deduction limit is 0.9 ppm. In addition, during the five weeks test, the response level was observed nearly constant, which indicated that the SnO2 bilayer sensor has long-term stability.

The development of methods and instruments for thermal conductivity measurement of standard core samples for petrophysical studies

The problem of obtaining qualitative data on the thermal conductivity of standard rock samples for petrophysical studies is considered. It is shown that the existing instruments for thermal conductivity measurement do not allow one to obtain reliable and accurate values of the thermal conductivity of small-sized rock samples. A laboratory installation for thermal conductivity measurement of standard rock samples with a diameter not less than 30 mm has been created. The installation was assembled and tested on small samples. Possible problems in the development, design and exploitation of the laboratory installation were analyzed. A software that allows automated collection and processing of the data has been developed. The key factors, negatively affecting the accuracy and reliability of thermal conductivity measurement results, are identified and excluded. There were unshielded thermocouples, potential changes between the hot and cold junctions (due to uneven melting of the water-ice mixture in the Dewar vessel, where the cold junction is immersed), incorrectly selected dimensions and shape of the object of study and the nonequilibrium ratio of the heat input and dissipation. The installation was tested on samples of pure tin standard and brass LS59 with known thermal conductivity. The thermal conductivity of a small-sized rock sample was measured with an error within 5.6 %.

Metal tools of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol: chemical and metallurgical characteristics

In this paper, the chemical composition of tools and ingots of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol region is characterized with identification of main recipes of the alloys using several analytical methods (spectral, X-ray fluorescence, and atomic emission spectrometry analyses carried out in the laboratories of the Institute of Archaeology of the Russian Academy of Sciences and the Institute of Inorganic Chemistry of the Si-berian Branch of the Russian Academy of Sciences). The complexes of the Petrovka Culture of the Sou-thern Trans-Urals have been dated by a set of AMS 14C dates to 19th–18th centuries BCE. Recently introduced in the scientific discourse 27 AMS 14C dates (settlement of Stepnoe and burial grounds of Stepnoe 1, 7 and 25) established an ear-lier interval of the Petrovka series — 2133–1631 BCE and point to the synchroneity of the cultures at the northern periphery of the Sintashta area in the local micro-region of the Southern Trans-Urals. The results of the analytical study of 106 metal tools and 70 ingots of the Petrovka Culture of the Southern Trans-Urals and south of Western Siberia are reported. The statistical processing of the analytical results with plotting correlation diagrams of Sn–As, Sn–Pb, As–Ag, As–Sb, and a frequency distribution histogram for the proportions of Sn allowed casting the metal into 4 metallurgical groups — pure copper and tin, arsenic-tin and arsenic bronzes. The first group subdivided into oxide and sulfidic samples. According to the geochemical peculiarity of the metal from the metal industry centers of Ustie 1, Kulevchi 3 and Shibaevo 1, several sources of oxide-carbonated ores were utilized for copper smelting — malachite and azurite-malachite deposits, while sulfidic chalcocite-covelline ores, and sometimes chalcopyrite-pyrite depositions, were added to the melt as a flux agent. The admixture of sulfides was carried out as an experiment and was not purposeful. Petrovka metallurgists supplied copper to the workshops of the Middle Tobol region — the sites of Ubagan 1, 2, 3 and Kamyshnoe 1, 2. The centers of the Petrovka Culture of the Southern Trans-Urals were domi-nated by the production of pure copper implements, including the metal smelted from the oxidized ore. To a lesser extent, low-alloyed bronze was used — Cu+Sn, Cu+Sn+As and Cu+As, whose feedstock was supplied by the kin-dred tribes of Central and Eastern Kazakhstan in the form of ingots and finished products along the eastern part of the Trans-Eurasian transport corridor of metal trade — over the Turgay trough and further along the extensive river system of the Tobol River and its tributaries. The highest concentration of tools of alloyed bronzes was recorded in the burial grounds of the Middle Tobol, which can be explained from the point of view of the prestige value of such goods and observance of special ceremonial practices.

Initial oxidation on 12 grain boundaries in pure TiN coating and on (Al,Si,Cr) doped Σ3 (111) grain boundaries: A first-principles calculations

In this work, using first-principles calculation method, the effect of twelve <110> symmetric tilt grain boundaries (GBs) on the initial oxidation behavior of TiN was studied. Firstly, the calculated GB energies show that for the TiN (1–10) surface with GBs from Σ3 to Σ27, Σ3 (111) GB possesses an extremely small GB energy (0.404 J/m2), while the other GBs possess a high energy (2.681∼4.834 J/m2). The electronic structure results show that the intrinsic characteristic of GB with high energy is well associated with the extra DOS peak existing in high energy region. Secondly, the oxygen adsorption results show that for TiN surfaces without GB, the order of adsorption energy of O is (100) > (110) > (111). When TiN (1–10) surface with different GBs, the sites at GBs are chemically more favorable sites for oxygen. The degree of weakening of oxidation resistance varies depending on the type of GBs, due to the apparent difference in oxygen adsorbability. Moreover, an interesting discovery is that Σ3 (111) GB provides a possibility to enhance the oxidation resistance of TiN, attributed to the easy introduction of Σ3 (111) GBs and suppressed inward progression of oxidation. Finally, the doping investigation in Σ3 (111) GB shows that among the three doping elements (Al, Si, and Cr), Si doping can further improve the oxidation resistance of (1–10) surface with Σ3 (111) GB in TiN, owing to the easy introduction of Si and formation of diffusion barrier layer of silicon oxides.

Understanding the structure-property correlation of tin oxide nanoparticles synthesized through the sol-gel technique

The present study aims at exploring the structural, morphological, optical, defects and phase related aspects of the sol-gel synthesized highly pure tin oxide (SnO2) nanocrystallites as a function of sample annealing temperature by carrying out experiments using various spectroscopic and analytical techniques. The X-ray diffraction (XRD) and high resolution transmission electron microscopic (HRTEM) studies confirmed the nanocrystallinity of the samples as the average sizes of the crystallites were found in between 10 and 20 nm. Williamson – Hall (W − H) analysis was employed for estimating the lattice strain and exact crystallite size of nanoparticles (NPs). The monotonous decrease of lattice strain with sample annealing temperature is consistent with increase of crystallite size by increase in temperature. The NPs exhibited some specific anomalous behaviour, among which a prominent one is the increased lattice parameters and unit cell volumes with the decrease of crystallite sizes. The optical band gap was observed to increase when the nanocrystallites became smaller in size. The latter aspect is attributable to the onset of quantum confinement effect, as observed in a few other metal oxide NPs. The atomic vibrations were characterized through distinct absorbance bands appeared in Fourier-transform infrared (FT-IR) spectroscopy. The photo-induced luminescence properties were studied by Fluorescence (FL) spectroscopy in terms of defects and/or oxygen vacancies related transitions. Positron annihilation lifetime spectroscopy (PALS) was employed to study the vacancy type defects, which were abundant in the samples and played crucial roles in modulating their properties. The results suggest the feasibility of tailoring the properties of SnO2 NPs synthesized through sol-gel route-for technological applications. It also provides the physical insight into the structural build-up process when crystallites were formed with a finite number of atoms, and their distributions were governed by the site stabilization energy. Since the samples of smaller crystallite sizes have remarkably larger defect concentrations.

Structural, optical and antibacterial activity of pure and co-doped (Fe & Ni) tin oxide nanoparticles

In this investigation, ferric (Fe) and nickel (Ni) co-doped tin oxide (SnO2) nanoparticles structural, optical, morphological, and antibacterial characteristics were synthesised, characterised, and examined. By employing SnCl2·2H2O and the transition metal precursors FeCl3 and NiCl2·6H2O with various Fe/Ni molar ratios, thermal annealing was carried out at a high temperature (700 °C). X-ray diffraction (XRD), UV–Visible spectroscopy, Photoluminescence (PL), FT-IR, and scanning electron microscopy (SEM) with energy dispersive X-ray techniques (EDX) were used to examine the materials' structural, chemical, optical, morphological, and anti-microbial capabilities. The average particle size of pure and co-doped SnO2 nanoparticles was determined to be around 52 nm and 15 nm, and SnO2 crystallites were observed to present tetragonal rutile structure with space group P42/mmm (No.136). Metal ions were replaced in the Sn lattice, as shown by Fe and Ni co-doped SnO2 nanoparticles. Pure and co-doped samples have capsule and sphere-like features in their SEM morphology. Using UV–visible diffuse reflectance spectroscopy, the optical property was examined, and it was observed that the band gaps for pure and co-doped SnO2 were 3.73 eV and 3.53 eV, respectively. The functional groups and incorporation of Fe and Ni in the prepared powder were also validated by FT-IR and EDX studies. By utilising the agar well diffusion technique and Nutrient agar, the antibacterial properties of pure, Ni-Fe co-doped SnO2 nanoparticles annealed at 700 °C were assessed. They were evaluated against various Gram-positive bacteria (Staphylococcus pheumoniae) and Gram-negative bacteria (Shigella dysenteria). The zone of incubation was found against the Gram +Ve and Gram −Ve bacterial strains.

Formate as Anti‐Oxidation Additives for Pb‐Free FASnI3 Perovskite Solar Cells

Pb‐free Sn‐based perovskite solar cells (PSCs) have significant potential for application in photovoltaic devices because of their suitable bandgap, low exciton binding energy, high carrier mobility, and long diffusion length. However, their performance is hampered by several issues. Sn‐based perovskites are highly susceptible to oxidation, which induces a high concentration of defects and degrades the chemical stability of the perovskite crystals. Herein, the anion formate (HCOO−) can effectively suppress the oxidation of Sn in the pure formamidinium tin triiodide (FASnI3) perovskite without using A‐site cationic additives. Moreover, the presence of formate results in a uniform pinhole‐free perovskite film with a low trap density, reduced charge carrier recombination, and improved charge extraction. Density functional theory calculations show that formate‐treated FASnI3 has improved stability against oxidative Sn degradation. The formate‐treated PSC achieves a power conversion efficiency of 12.11% at a high open‐circuit voltage of 0.71 V. The device exhibits improved stability in ambient air in which it maintained over 80% of its initial power conversion efficiency after 180 min because oxidation is inhibited owing to the strong interaction between Sn and formate.

Fracture of 99.90 Pure Tin Tubes

Fracture of 99.90 Pure Tin Tubes

Structural and FTIR Studies of Pure and Zinc Doped SNO2NanoParticles

Pure and zinc-doped tin oxide nanoparticles were synthesized by the chemical co-precipitation method. The structural studies were carried out by X-Ray Diffraction pattern. XRD pattern reveals the tetragonal rutile structure of tin oxide nanoparticles. Fourier Transform Infrared Spectroscopy studies were used to identify the chemical information of pure and zinc-doped tin oxide nanoparticles. The crystallite size of pure tin oxide nanoparticles is 9 nm obtained from the X-ray diffraction pattern. The Zn ions are incorporated into the tin ions. It is suitable candidate for gas sensor applications.

Roles of different components of complex inclusion in pitting of 321 stainless steel: Induction effect of CaS and inhibition effect of TiN

Pitting behavior of 321 stainless steel (SS) in sodium chloride solution was studied by potentiostatic pulse technique triggering pits. Pure TiN inclusion and complex inclusion with core-shell structure are found in 321 SS. The former has no effect on pitting performance, while CaS in the latter is the exact inducer of pitting. Mechanism of pitting initiation and propagation induced by complex inclusions was proposed. When CaS content differs little, inhibition effect of TiN shell on pitting propagation is the main reason why a complex inclusion with higher TiN content is more resistant to pitting.

In-Situ Fabrication, Microstructure and Mechanical Performance of Nano Iron-Rich Precipitate Reinforced Cu and Cu Alloys

In this paper, the research progress on the strengthening of copper and copper alloy is reviewed. The research shows that traditional strengthening methods are often accompanied by the decrease of plasticity, and there are limitations in size, cost, and other aspects in the process. The in-situ nanoparticle strengthening and plasticizing technology proposed in recent years can avoid the above problems. In this paper, the idea of in-situ nanoparticle strengthening is introduced to realize the simultaneous enhancement of strength and ductility of as-cast pure copper and tin bronze alloys. The effects of in-situ precipitation of iron-rich nanoparticles on the microstructure, and mechanical properties of different copper alloy systems, are systematically elucidated based on the former characterization and mechanical testing results. The results show that the in-situ introduction of iron-rich nanoparticles in the copper systems induces the formation of a nano precipitate-fine grain (NPFG) structure, which greatly improves the strength and ductility of copper alloys. The evolution of size, distribution, number density, morphology evolution in iron-rich nanoparticles, and the formation mechanism of NPFG structure, as well as the mechanism of NPFG strengthening and toughening, are summarized. An industrial-applicable casting process is proposed to prepare bulk NPFG structured copper alloys with complex shape, high strength, and high ductility.

Corrosion and hardness characteristics of Ti/TiN-modified Ti6Al4V alloy in marine environment

Ti/TiN multilayer coatings with different modulation periods and modulation ratios were prepared on Ti6Al4V alloy substrates by radio frequency (RF) magnetron sputtering to enhance the corrosion and hardness behavior of Ti6Al4V. The phases, surface and cross-sectional morphologies of the coatings were characterized by XRD and SEM. Corrosion behavior of all the samples was carried out in NaCl solution (3.5 wt%) at 298 K, and the hardness and elastic modulus of the coatings were analyzed by the nanoindentor. When the modulation period is 16 and the modulation ratio is 2:1, the resistance of the coating reaches the maximum value (378.5 kΩ cm2), which is 13 times that of the substrate (28.7 kΩ cm2), 6.9 times that of the pure Ti coating (54.6 kΩ cm2), and 8.2 times that of the pure TiN coating (46.2 kΩ cm2). Although the addition of titanium layers reduces the overall hardness of the coating (the hardness of the pure TiN is 14.0 Gpa), the hardness still can reach 10.8 Gpa when the modulation period is 16.

Singular magnetic properties of porous anodized tin oxide ceramics

Porous SnO2 films were successfully prepared using pure tin foils by a convenient electrochemical anodization method in 0.5 M NaOH solutions. Interestingly, the same sample can simultaneously exhibit room temperature ferromagnetism, paramagnetism and diamagnetism. Moreover, the magnetic behavior is related to the direction of the applying magnetic field, showing obvious magnetic anisotropy. A reasonable explanation for this phenomenon was given by analyzing the morphology, magnetic characterization, and spectral analysis of the films, combined with the knowledge of solid physics. This research will be helpful in expanding the application of porous SnO2 films.

Understanding the electrochemical behavior of Sn(II) in choline chloride-ethylene glycol deep eutectic solvent for tin powders preparation

• Tin could be efficiently electrodeposited from ChCl-EG DES without any additives. • The nucleation mechanism and kinetics were assessed from j - t plots. • Homogeneous tin powders with dendritic structure could be obtained with the current efficiency of 96.4%. Tin is one of the vital substances in the material and chemical industry. Deep eutectic solvent (DES) possesses excellent physicochemical properties for metal preparation. In this study, the electrochemical behavior of Sn(II) and metallic tin preparation in choline chloride-ethylene glycol (ChCl-EG) DES were investigated. Linear sweep voltammetry is carried out to study the effects of substrate material (Ni, Cu, Pt, C, Fe, Al, W, glassy carbon (GC) and Ti), temperature (313–353 K) and SnCl 2 concentration (10–100 mM) on the electrochemical behavior of Sn(II)/Sn. Results demonstrate that metallic tin is easier to be prepared on the Ni electrode, and increasing temperature and SnCl 2 concentration both facilitate the reduction of Sn(II). Electrospray ionization mass spectrometry (ESI-MS) shows that the main form of Sn(II) is [SnCl 3 ] - . Chronoamperometric tests indicate that with the increase of applied potential, the nucleation of Sn(II) on the nickel electrode becomes close to the instantaneous nucleation. Simultaneously, the nucleation rate and the number of active sites on the electrode surface increase significantly. Pure tin with a dendritic structure could be prepared with higher current efficiency of 96.4% and lower energy consumption of 320.5 kW·h·t −1 without any additives. All these studies provide a fundamental basis for the preparation of tin powders in ChCl-EG DES.

Exploration of Spectroscopic Study of Screen-Printed Tungsten Oxide: Tin Oxide Nano-Composite Powder Fired at High Temperature

Abstract: Thick films of pure Tin oxide (SnO2) and composite 1%, 3%, 5%, 7% and 9 % tungsten oxide (WO3) incorporated into pure Tin oxide (SnO2) were prepared with standard screen printing technique. All samples were prepared on glass substrate and subjected to drying and firing at 5000C at 5 hours in muffle furnace. Thick films of tin oxide (SnO2) and composite 1%, 3%, 5%, 7% and 9 % Tungsten Oxide (WO3) incorporated into pure tin oxide (SnO2) were examined for Scanning Electron Microscopy (S.E.M), Energy Dispersive X-ray Analysis (E.D.A.X), X-ray diffraction (X.R.D), Fourier Transform infra-Red (F.T.I.R) and Ultra-Violet-visible spectroscopy (U.V) to investigate surface morphology, elemental analysis, crystalline Phases of films, vibrational and spectroscopic study respectively. The spectrophotometric parameters such as absorbance and absorption coefficient were also a part of investigation. The UV-visible spectrophotometric study was encountered in terms of absorbance and absorption coefficient along with varying percentage composition.