Tin Powder Research Articles

Synthesis and Analysis of Ternary Oxide Nanomaterial for Electro-thermal Applications

Binary Semiconducting Oxides have quite stable properties. The quest for enhancing the properties of materials even further, leads us to evaluate Zinc-Tin-Oxide, which is a ternary semiconducting oxide material known for its unique properties. ZTO nanomaterial was synthesized using Solvo-Thermal method with different molar ratios of Zinc and Tin varying with 1:1, 3:7 and 7:3. Slovo-Thermal method is a very efficient method when compared to other methods to synthesize at low temperatures. In the present work Zinc tin oxide (ZTO) nanomaterial has been successfully synthesized in which zinc and tin powders were separately mixed with ethanol solution under slow stirring. In this process a mild base of Na2CO3 is used as a mineralizer and ethanol as a solvent which was later subjected to low temperature of 100°C. Characterization techniques like SEM, EDS, XRD, UV-Visible and TGA were used with a view to study the growth, optical and thermal properties of ZTO nanomaterial.

Thermoelectric Figures of Merit of Zn4Sb3 and Zrnisn-based Half-heusler Compounds Influenced by Mev Ion-beam Bombardments

Semiconducting β-Zn4Sb3 and ZrNiSn-based half-Heusler compound thin films with applications as thermoelectric (TE) materials were prepared using ion beam assisted deposition (IBAD). High-purity solid zinc (Zn) and antimony (Sb) were evaporated by electron beam to grow the β-Zn4Sb3 thin film while high-purity zirconium (Zr) powder and nickel (Ni) tin (Sn) powders were evaporated by electron beam to grow the ZrNiSn-based half-Heusler compound thin film. Rutherford backscattering spectrometry (RBS) was used to analyze the composition of the thin films. The grown thin films were subjected to 5 MeV Si ions bombardment for generation of nanostructures in the films. We measured the thermal conductivity, Seebeck coefficient, and electrical conductivity of these two systems before and after 5 MeV Si ions beam bombardment. The two material systems have been identified as promising TE materials for the application of thermal-to-electrical energy conversion, but the efficiency still limits their applications. The electronic energy deposited due to ionization in the track of MeV ion beam couldcause localized crystallization. The nanostructures produced by MeV ion beam can cause significant change in both the electrical and the thermal conductivity of thin films, thereby improving the efficiency. We used the 3ω-method (3rd harmonic) measurement system to measure the cross-plane thermal conductivity, the van der Pauw measurement system to measure the electrical conductivity, and the Seebeck-coefficient measurement system to measure the cross-plane Seebeck coefficient. The thermoelectric figures of merit of the two material systems were then derived by calculations using the measurement results. The MeV ion-beam bombardment was found to decrease the thermal conductivity of thin films and increase the efficiency of thermal-to-electrical energy conversion.

Fabrication of NiTi shape memory alloy by Micro-FAST

A NiTi shape memory alloy, known as nitinol, has been intensively studied for last five decades. The NiTi alloy with large size is commonly produced by vacuum sintering, thermal explosion mode of self-propagating high-temperature synthesis (TE-SHS) and spark plasma sintering (SPS). These methods are, however, rarely utilized for the forming of miniature and micro-sized components and have their own limits and disadvantages, such as long process chains and low efficiency with the processes. In the study reported in this paper, an innovation in rapid powder consolidation technology, called Micro-FAST (combining micro-forming and electric-current activated sintering techniques (FAST)) is introduced for the forming of micro-components in which the loose powders are loaded directly into the die, followed by electric-sintering. In the study, Φ4.0 mm × 4.0 mm miniature cylinders were formed with pre-alloyed NiTi powders. Sintered sample with relative density of 98.65% has been fabricated at a sintering temperature of 1150 °C in a relatively short cycle time (119.5 s). Based on the results of SEM and XRD, it was found that the densified samples with Ni3Ti, NiTi and NiTi2 phases were produced.

Effect of synthesis temperature and N2/O2 flow on morphology and field emission property of SnO2 nanowires

A large amount of tin oxide (SnO2) nanowire arrays were synthesized on the flexible conductive carbon fiber substrate by thermal evaporation of tin powders in a tube furnace. The temperature, as well as the flow rate of the carrier N2 gas and the reaction O2 gas, plays an important role in defining the morphology of the SnO2 nanowires. Morphology and structure of the as-grown SnO2 samples are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). Results show that all the samples possess a typical rutile structure, and no other impurity phases are observed. The morphology changes from rod to wire with the increase of reaction temperature. Ratio of length to diameter of the nanowires increases first and then decreases with the flow ratio of N2/O2 gas. The optimum synthesis conditions of SnO2 nanowire are: reaction temperature 780 ℃, N2 and O2 flow rates being 300 sccm and 3 sccm respectively. In our growth process, the nanowire grows mainly due to the vapor-liquid-solid (VLS) growth process, but both the VLS process and surface diffusion combined with a preferential growth mechanism play the important role in morphology evolution of the SnO2.Field emission measurements for Samples 1-6 are carried out in a vacuum chamber and a diode plate configuration is used. Relationship between the growth orientation, aspect ratio, density and uniformity of the arrays and field emission performances will be investigated first. Results reveal that the field emission performance of SnO2 nanostructures depends on their morphologies and array density. The turn-on electric field (at the current density of 10 upA/cm2) decreases and the emission site density increases with tin oxide array density, and the turn-on electric field of Sample 5 (synthesized at 780 ℃, nitrogen and oxygen flow rates being 300 sccm and 3 sccm respectively) is about 1.03 V/m at a working distance of 500 m. By comparison, for the turn-on electric fields of the not well-aligned SnO2 nanowire arrays we have 1.58, 2.13, 2.42, 1.82, and 1.97 V/m at 500 m. These behaviors indicate that such an ultralow turn-on field emission and marked enhancement in (～ 4670) can be attributed to the better orientation, the good electric contact with the conducting fiber substrate where they grow, and the weaker field-screening effect. Our results demonstrate that well-aligned nanowire arrays, with excellent field-emission performance, grown on fiber substrate can provide the possibility of application in flexible vacuum electron sources.

Microstructure and mechanical properties of as-cast quasibinary NiTi–Nb eutectic alloy

Ni40Ti40Nb20 is reported in the literature as a eutectic composition in the quasi-binary NiTi–Nb system. Eutectic and near-eutectic alloys find applications in various fields, including hydrogen permeation, energy damping, and liquid phase bonding of NiTi structures. In this study, we examine a cast Ni–Ti–Nb alloy with the above eutectic composition. Prealloyed, near-stoichiometric NiTi powders and pure Nb powders are blended and heated above the eutectic temperature to create a melt with the eutectic composition. After solidification, the ingot shows some elemental segregation at its top and bottom, but a large middle region exists with a homogeneous eutectic structure. The eutectic has average composition of Ti–40.1Ni–19.6Nbat% and consists of Nb-rich lamellae (Nb–19Ti–10Ni) dispersed within a NiTi-rich matrix (Ti–41Ni–15Nb). Under monotonic compressive deformation, the eutectic alloy yields at 630MPa, and then shows a linear hardening region, where both plastic and superplastic deformation are active, until a stress of 1080MPa is reached at an applied strain of 14.7%. On unloading, some superelastic strain is recovered. Upon unloading during compressive load–unload cycling, the eutectic alloy exhibits approximately twice as much superelastic recovery as elastic strain recovery, regardless of the maximum cycle strain.

Fabrication of Ti2AlN ceramics with orientation growth behavior by the microwave sintering method

Porous Ti2AlN ceramic, which was measured to be 3.23g/cm3 about 74.9% of its theoretical value, was successfully synthesized and simultaneously consolidated from starting raw materials of Ti, Al, and TiN powders with a near-stoichiometric molar ratio of 1:1.03:1 by a microwave sintering method at 1200°C for 30min in an argon atmosphere. When sintered at 1200°C for 1h, the Ti2AlN grain showed a preferred growth behavior along the c-axis in the final ceramic, as shown by the results of an X-ray diffraction study. The Lotgering orientation factor on the surface of as-sintered Ti2AlN ceramic was as high as f(00ℓ)=0.598. A traditional synthesis method in a quartz tube furnace was also applied to synthesize the materials under the same conditions, but this did not result in similar preferred grain growth phenomenon. Factors affecting the orientation were discussed, and an underlying growth mechanism was suggested. Also, a dense Ti2AlN sample was obtained by re-sintering the porous Ti2AlN sample using a spark plasma sintering method. As a result, the orientation was maintained, and the density was measured to be 4.21g/cm3, which reached 97.6% of its theoretical value.

Effects of Ni/Co Metal Binder Phase on Mechanical Properties of Ti(C,N)-Based Cermets

Ti(C,N)-based cermets were prepared by pressureless sintering using micron-sized TiC and TiN powders as main starting materials and Ni and Co as metal binders. The fracture micrographs of Ti(C,N)-based cermets were observed by SEM. The effects of metal binder phase content on porosity and mechanical properties of Ti(C,N)-based cermets were investigated. The results show that when sintering at 1450 °C for 50min, typical core/rim microstructure is observed in the cermets, which is compact and distributed homogeneously, the density and relative density are 5.9 g/cm3 and 95.6%, respectively. Intergranular fracture is the main crack propagation mode, with a few of the transgranular fracture, and there are more dimples and tearing ridges in the fracture surface. Using the same sintering process, Ti(C,N)-based cermets with metal binder content of 10%Ni5%Co has a compact microstructure and fine grains, the metal binder phase is dispersed more evenly, the best vicker hardness, bending strength and fracture toughness of Ti(C,N)-based cermets are 15.8 GPa, 885.5MPa and 9.7 MPa·m1/2, respectively. However, Ti(C,N)-based cermets with Ni replaced of high Co content will generate some brittle intermetallic compound, its toughness is inferior to the metal binder phase, which reduces the strength and toughness of Ti(C,N)-based cermet materials.

Obtaining the Nanostructured Nitride Composition TiN-BN Powder by the Self-Propagating High-Temperature Synthesis from the Azide KBF<sub>4</sub>-NaN<sub>3</sub>-Na<sub>2</sub>TiF<sub>6</sub> and "NH<sub>4</sub>BF<sub>4</sub>-NaN<sub>3</sub>-Na<sub>2</sub>TiF<sub>6</sub> Systems

This paper presents the results of a study on the preparation of nanostructured nitride composition TiN-BN in the boron halide - sodium azide - titanium halide system by the azide SHS technology. SHS-Az technology makes it possible to produce powders having the desired properties, only in one step, without blending separately prepared powders of titanium nitride and boron nitride, and to obtain the final product in the form of micro-and nanosized powder nitride compositions TiN-BN by using complex halides of titanium and boron. Thus, the composite powder TiN and BN obtained from the KBF4-NaN3-Na2TiF6» and «NH4BF4-NaN3-Na2TiF6 systems can be classified as a nanostructured powder (nanopowder).

Thermal and Mechanical Properties of SiC–TiC0.5N0.5 Composites

SiC–TiC0.5N0.5 composites were fabricated from β‐SiC and TiN powders with 2 vol% equimolar Y2O3–Sc2O3 additives by conventional hot pressing. Thermal and mechanical properties of the SiC–TiC0.5N0.5 composites were investigated as a function of initial TiN content. Relative densities of ≥98.9% were achieved for all samples. The addition of a small amount of TiN increased thermal conductivity, flexural strength, and fracture toughness of SiC ceramics. However, further addition of TiN in excess of 10 and 20 vol% deteriorated both thermal conductivity and flexural strength of the composites, respectively. In contrast, the fracture toughness of the composites increased continuously from 4.2 to 6.2 MPa∙m1/2 with increasing initial TiN content from 0 to 35 vol%, due to crack deflection by TiC0.5N0.5. The maximum values of thermal conductivity and flexural strength were 224 W/m K for a 2 vol% TiC0.5N0.5 and 599 MPa for a 10 vol% TiC0.5N0.5 composite.

Shock compressibility of high-porosity copper and tin powders

The particle and wave velocities in copper and tin samples with an extremely high porosity are measured by a magnetoelectric method. Relations between the wave and particle velocities are obtained for copper with a density of 0.76 and 0.54 g/cm3 (porosity factor of 12 and 16, respectively) and for tin with a density of 1.9 g/cm3 (porosity factor of 3.9). The obtained data are used to find other hydrodynamic parameters of a compressed substance (density, pressure, specific internal energy) using the laws of conservation. The parameters of the state of copper and tin are found in the region of the P-V-T states of the metals that has not been studied earlier and corresponds to low densities and high internal energies.

Microstructure and Property Study on Wear Resistant Composite Coating Produced by Ultrasonic-Assisted Argon-Arc Clad Injection

Ni60 self-fluxed alloy powder was coated on the surface of Q235 steel plate by the ultrasonic-assisted argon-arc clad injection technology, then TiC, TiN and Co powder were sprayed by the modificated injection device, and at the same time the powder was vibrated by the ultrasonic-assisted vibration device self-designed. The results shows that through the innovative technology, the wettability and dispersity of the reinforced phase are ameliorated, so as the elements diffusion and binding strength of the cladding layer with the matrix. The microhardness of the composite coating is 1.1 times than that of the coating without ultrasonic assisted, and 4.8 times than Q235 as the matrix. The wear resistance of the composite coating is 11 times than Q235, and 1.6 times than that of the coating without ultrasonic assisted.

Transesterification of jojoba oil, sunflower oil, neem oil, rocket seed oil and linseed oil by tin catalysts

The methanolysis of jojoba oil has been studied in the presence of tin powder, dibutyltin diacetate (C4H9)2Sn(OOCCH3)2, dioctyltin diacetate (C8H17)2Sn(OOCCH3)2, dibutyltin oxide (C4H9)2SnO, dioctyltin oxide (C8H17)2SnO, diphenyltin oxide (C6H5)2SnO, dibutyltin chloride dihydroxide (C4H9)2Sn(OH)2Cl, butyltinhydroxide hydrate (C4H9)Sn(=O)OH.xH2O, Ni nanoparticles and Pd nanoparticles act as catalysts. Among these, 1 weight % of dibutyltin diacetate shows the maximum conversion. Then, methanolysis of sunflower oil, neem oil, rocket seed oil and linseed oil into methyl esters studied in the presence of 1% dibutyltin diacetate as a catalyst and was compared their percentage conversions. The experimental yield for the conversion of jojoba oil, sunflower oil, neem oil, rocket seed oil and linseed oil into biodiesel was found to be 71%, 51%, 50.78%, 40.90% and 39.66%, respectively. The experimental yield of the conversion of jojoba oil into methyl esters was found to be increased up to 96% by increasing reaction time, without emulsion formation. The synthesis of jojoba seed oil biodiesel (JSOB), soybean oil biodiesel (SOB), neem oil biodiesel (NOB), rocket seed oil biodiesel (RSOB) and linseed oil biodiesel (LSOB) was confirmed by NMR (1H &13C) and FT-IR analyses of biodiesel.

Local melting in Al embedded with TiNi powder induced by microarea self-propagating high-temperature synthesis

Microarea self-propagating high-temperature synthesis (microSHS) was ignited by the heat of mixing generated at the boundaries between an Al matrix and TiNi particles during plastic deformation at room temperature. The temperature of the boundaries was rapidly increased by microSHS; the temperature elevation resulted in local melting of the TiNi particle and the surrounding Al matrix, because the heat of mixing was localized in the vicinity of the TiNi particle although the amount of the heat of mixing was limited. Since the amount of the local melting region induced by microSHS is restricted, not only major elements (i.e. Al, Ti and Ni) but also impurities were involved in the solidification followed by local melting. As a result, FeNi nanoprecipitates, which have not been reported in SHS studies, were formed by inclusion of Fe, initially included as an impurity in raw materials. The formation mechanism of FeNi nanoprecipitates is discussed based on reference to the Al–Fe–Ni ternary alloy phase diagram. It is expected that local melting induced by microSHS is a key phenomonon for amorphization during severe plastic deformation of elemental sheets.

Selective laser sintering of composite copper–tin powders

Abstract

Sn-Polyacrylate Composite Electrode for Advanced Na-Ion Batteries

Na-ion batteries are attractive rechargeable batteries as Li-free batteries. Sodium resources are abundant, inexpensive elements and unlimited everywhere, unlike lithium availability. Additionally, relatively low redox potential of sodium is slightly higher, 0.3 V, than that of Li/Li+. Therefore, many researchers extensively study about Na-ion batteries nowadays and the electrode performance is significantly improved, which is being competitive for Li-ion batteries. We have demonstrated approximately 300 mAh/g discharge capacity after 50 cycles by using hard-carbon electrodes in Na cells.[1] In order to achieve higher energy battery, electrode materials with high reversible capacity is needed. Thus we have examined group 14 elements (C, Si, Ge, Sn, and Pb) as the potential negative electrodes materials for Na-ion batteries.[2] In our previous report, we demonstrated acceptable electrode performance with tin, approximately 500 mAh/g of reversible capacity after 30 cycles.[2] However, reversible capacity was lower than that of expected capacity (847 mAh/g based on the formation of Na15Sn4).[3]In this study, the factors affecting electrode performance of tin electrochemically alloying with Na are described; slurry conditions, cut-off voltages and so on. After the optimization of tin composite electrodes, finally, we have demonstrated more than 650 mAh/g of reversible capacity with good capacity retention. Nanosized tin powder (<150 nm, Sigma-Aldrich Co., Ltd), graphite, and sodium polyacrylate (PANa) were mixed with 80:10:10 (wt%) to prepare slurry with deionized water mixed with or without methanol (5 vol%) and were cast onto Al foil to make composite electrodes. The electrode was tested in aprotic Na cell with NaPF6PC solution with FEC (2 vol%) additive. As shown in Fig.1, the higher reversible capacity (approximately 700 mAh/g) is obtained by addition of 5% methanol to the slurry. Approximately 200 mAh/g discharge capacity is increased compared with the slurry prepared without the addition of methanol. Change in the electrode morphology prepared with or without methanol in the slurry was observed by SEM (Fig. 2). SEM observation reveals that the uniform morphology and better dispersion of the active materials for the composite electrode prepared with methanol-added dispersant. It indicates that methanol additive is effective to improve the dispersion of tin and carbon materials in the aqueous slurry, resulting in better electrochemical properties in Na cells. Based upon these results, we will discuss the effects of cut-off voltages in relation to the changes in the surface of tin electrodes characterized by secondary ion mass spectroscopy and photoelectron spectroscopy in synchrotron facility. References : [1] M. Dahbi, N. Yabuuchi, K. Kubota, K. Tokiwa, S. Komaba, submitted. [2] S. Komaba et al., Electrochem. Commun., 21, 65 (2012). [3] L. D. Ellis et al., J. Electrochem.Soc., 159, A1801 (2012).

Wear Resistant Surface Composite Produced by Ultrasonic-Assisted Argon-Arc Clad Injecting Ti(C, N)

This experiment was on the basis of the argon-arc clad injection technology, Ni60 self-fluxed alloy powder was coated on the surface of Q235 steel plate, then TiC, TiN, MoC and Co powder were sprayed by the modificated injection device, and at the same time the powder was vibrated by the ultrasonic-assisted vibration device self-designed. So the sprayed powder particles were smaller, shape was more regular, and distribution more uniform. The results show that the microhardness of composite coating was more than 5 times than that of the matrix, and the wear volume was about 1/5 than the matrix. The good combination, high strength and high wear resistance composite coating was obtained.

Long‐Range Ordered Structure of Ti–B–C–N in a TiB2–TiCxN1−x Eutectic Composite

A TiB2–TiCxN1−x quasi‐binary eutectic composite, with a rod‐like faceted texture and a long‐range ordered structure of Ti–B–C–N, was prepared by the arc‐melting of TiB2, TiC, and TiN powders. Hexagonal single‐crystalline TiCxN1−x rods were grown in a single‐crystalline TiB2 matrix with a crystal orientation relationship of TiB2 //TiCxN1−x and TiB2 [0001]//TiCxN1−x [111]. A long‐range ordered structure of Ti–B–C–N was formed by the intermixing of the coherent interplanar spacings of seven TiB2 (0001) and nine TiCxN1−x (111) planes.

A Comparative Study of the Tribological Behavior of Tin Powder Clad on the JIS SKD11 Tool Steel with the GTAW Method

This work focused on the wear performance of the clad layers which were formed with cladding titanium nitrides (TiN) powder on the JIS SKD11 tool steel by the gas tungsten arc welding (GTAW) method. A rotating type tribometer was used to evaluate the wear behavior of the clad specimens under different sliding conditions. Furthermore, a nanoindenter was used to measure the hardness and elastic modulus of the reinforcements. According to the wear test results, the wear performance of the specimens cladded with TiN powder was better than that of the JIS SKD11 tool steel specimens. During dry sliding wear test, the clad layers exhibited a strong wear resistance because they contained the hard TiN reinforcements. Therefore, the wear performance of the clad layers was substantially better than that of the SKD11 specimens under all the test conditions in this study. In addition, produced oxide films might influence the wear behavior of different specimens during the wear testing, and oxidation wear would even dominate the wear behavior of the clad layers under some conditions.

Deposition Mechanisms and Oxidation Behaviors of Ti-Ni Coatings Deposited in Low-Temperature HVOF Spraying Process

Three kinds of Ti-Ni powders were deposited on 316L stainless steel by low-temperature high-velocity oxygen fuel (LT-HVOF) spraying process, respectively. Deposition mechanisms and oxidation behaviors of the coatings were researched in this paper. The coating deposited from TiNi intermetallic powder had obvious laminar structure and the oxygen content was the highest among the three kinds of coatings. The oxygen content of the coating deposited from small-sized Ni-clad Ti powder was still high due to the melting of parts of particles. However, most of the coarse Ni-clad Ti powder was deposited in solid states without changes of chemical compositions and phase compositions. The oxygen content of the coating deposited from coarse Ni-clad Ti powder was the lowest among the three kinds of coatings. It indicated that the deposition behavior of the coating could effectively preserve the inner titanium from oxidation. The results of the present research demonstrated that it is entirely feasible to deposit active metal materials such as titanium and titanium alloy through the optimizing selection of powder in the LT-HVOF process.

Lamellar and Rod-Like Eutectic Growth of TiB&lt;sub&gt;2&lt;/sub&gt;-TiC-TiN Composites by Arc-Melting

TiB2-TiC, TiB2-TiN and TiB2-TiCxN1-x composites were prepared by arc-melting mixtures of TiB2, TiC and TiN powders. 28TiB2-72TiC (mol%) composite showed a lamellar eutectic structure, while 55TiB2-45TiN (mol%) composite with a lamellar structure consisted of TiB2, TiN and TiB. 36TiB2-44TiC-20TiN (mol%) was a quasi-binary eutectic composite having a rod-like structure.