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Abstract A coordinate change of conjugation twin boundaries in Ni-Mn-Sn single crystals is studied with scanning electron microscopy. During mechanical training, the so-called orthogonal shear process initiates variant reorientation leading to the replacement of the main with conjugation type I twin boundaries. The experimental data demonstrate that highly organized redistribution of adjacent variants, in the neighboring areas, is then critical for the removal of conjugation boundaries by coordinated secondary twinning. In addition, a more complex variant reorientation mechanism is uncovered and it is found to allow for transitioning between non-conjugate twin systems. The proposed mechanism appears consistent with the orientation relationship between austenite and martensite, which is controlled by a shear deformation and martensite crystallography leading to an equal distribution of martensitic variants. This contribution complements the existing theory of martensite crystallography providing direct evidence for the general nature of the orthogonal shear process as a first step in variant reorganization during mechanical training of martensite. Highlights • Removal of type II twins and type II inter-plate boundaries by a coordinate change of conjugate twin planes. • Orthogonal shear process affects the neighboring colonies allowing transition between non-conjugated twin systems. • Coordinated secondary twinning generates shear-induced rotation reducing the number of orientations from 24 to 12. • All rotations during training procedure are symmetric with respect to austenite orientation. [ABSTRACT FROM AUTHOR]

The reaction within Ni/Sn/Cu microjoints has been investigated with a 10 μm initial thickness of Sn so that Sn was quickly consumed in the early stage of the reaction, transforming the joints into full intermetallic joints. Accordingly, the emphasis of the present study is on the materials interactions in such full intermetallic joints. Ni/Sn/Cu sandwiches were prepared by thermal compression bonding. High-temperature storage tests were conducted at 150°C, 180°C, and 200°C for different time periods. The hardness and Young's modulus of the intermetallic joints were measured using nanoindentation. The key finding of this study is that, once Sn was exhausted, the originally planar (Cu,Ni)3Sn grew preferably along the grain boundary of (Cu,Ni)6Sn5, creating a highly nonuniform (Cu,Ni)3Sn growth front. Both the hardness and elastic modulus increased with the Ni concentration in the intermetallics. [ABSTRACT FROM AUTHOR]

Under the simultaneous influence of volume shrinkage and surface solder diffusion, the microstructural evolution in Ni/Sn/Ni microjoints exhibits a conformable tendency among different joint sizes. This conformable tendency is the necking of the Sn layer and the initiation of voids which occur only near the periphery of the Sn layer. The reasons for this joint-size dependency have been theoretically evaluated and proposed in this study. This dependency remains applicable until the Ni3Sn4 layers growing in opposite directions impinge on each other. Afterward, microvoids are able to form everywhere along the centerline of the joints. It is hypothesized that the electrical and mechanical performance of microjoints is significantly related to the microstructures in these joints. With the help of the joint-size dependency proposed in this study, it is expected that the dimensional design of microjoints is capable of being optimized to assure high reliability. [ABSTRACT FROM AUTHOR]

In this paper, novel three dimensional hierarchical porous Sn-Ni (3D-HP Sn-Ni) alloys were investigated as a promising anode for high-performance Li ion batteries (LIBs), which was fabricated by pulse electrodeposition of mesoporous Sn-Ni alloy made of ultrafine nanoparticles on the 3D nanoporous copper substrate from chemical dealloying of as-cast Al 55 Cu 45 (at.%) alloy slices in the HCl solution. The results show that the as-obtained 3D-HP Sn-Ni alloys are typically characteristic of open, bicontinuous, interpenetrating bimodal pore size distribution comprising large-sized (hundreds of nm) ligament-channel network architecture with highly porous channel walls (several nm). Compared to the two dimensional nanoporous Sn-Ni (2D-NP Sn-Ni) thin films, the 3D-HP Sn-Ni alloys as anode for LIBs show superior cycling stability with reversible specific capacity of 0.25 mAh cm −2 and coulombic efficiency of more than 95% up to 200 cycles. Moreover, the reversible capacity as high as 0.22 mAh cm −2 can be achieved even after a series of high-rate charge–discharge cyclings. The satisfactory electrochemical properties can be mainly ascribed to the unique 3D hierarchical porous structure, large contact surface area between active material and electrolyte, as well as good buffer effect of inactive component, which is greatly beneficial to alleviate the huge volume variation, enhance the loading mass of active material, shorten the Li + migration distance and improve the electron conductivity. We believe that this present work can provide a promising anode candidate towards practical application of high-performance LIBs. [ABSTRACT FROM AUTHOR]

Physical properties of Ni 3 Sn x intermetallic compounds as well as the interfacial properties of Ni/Ni 3 Sn interface were investigated by first-principles calculations for studying the crack initiation behavior and mechanism of the novel Nickel-Tin TLPS bonding layer. The results indicated that, for Ni and Ni 3 Sn x intermetallic compounds, Ni 3 Sn 4 intermetallic compound shows the smallest deformation resistance, the largest brittleness and strongest micro-cracks initiation tendency because of the largest average bond length, the biggest crystal asymmetry and the most complex bonding characteristic, so it will be cracking preferentially in all of the Ni 3 Sn x intermetallic compounds under the stress condition. For the Ni/Ni 3 Sn interfaces, Ni (111)/Ni 3 Sn (111) interface with OT stacking sequence shows the weakest interfacial bonding strength with adhesion energy of 3.11 J/m 2 , and it will crack at layer 1′-1 with only 12% imposed strain, so it can be considered as the weakest interface under the stress condition in all of the Ni/Ni 3 Sn interfaces. [ABSTRACT FROM AUTHOR]

For high-temperature-resistant packaging of new generation power chip, a chip packaging simulation structure of Ni/Ni-Sn/Ni was bonded by a transient liquid-phase sintering process. High-temperature aging experiments were carried out to investigate joint heat stability. The microstructural evolution and mechanism during aging, and mechanical properties after aging were analyzed. The results show that the 30Ni-70Sn bonding layer as-bonded at 340°C for 240 min is mainly composed of Ni3Sn4 and residual Ni particles. When aged at 350°C, because of the difficulty of nucleation for Ni3Sn and quite slow growth of Ni3Sn2, the bonding layer is stable and the strength of that doesn’t change obviously with aging time. When aging temperature increased to 500°C, however, the residual Ni particles were gradually dissolved and the bonding layer formed a stable structure with dominated Ni3Sn2 after 36 h. Meanwhile, due to the volume shrinkage (4.43%) from Ni3Sn2 formation, a number of voids were formed. The shear strength shows an increase, resulting from Ni3Sn2 formation, but then it decreases slightly caused by voids. After aging at 500°C for 100 h, shear strength is still maintained at 29.6 MPa. In addition, the mechanism of void formation was analyzed and microstructural evolution model was also established. [ABSTRACT FROM AUTHOR]

In this work, Cu-15Ni-8Sn components were manufactured by selective laser melting (SLM) with a near full density of about 99.4%. The microstructures and phase precipitation of the as-fabricated Cu-15Ni-8Sn alloy were characterized by X-ray diffraction (XRD), electron probe microanalyzer (EPMA), electron back-scattered diffraction (EBSD), and transmission electron microscope (TEM). It was demonstrated that the as-fabricated Cu-15Ni-8Sn alloy shows α-phase with γ-precipitates by XRD and TEM. The size of the grains of α-phase is in the range of 5~20 μm with random orientation distribution. The γ-precipitate is a Sn- and Ni-rich phase distributed dispersedly in matrix and accumulatively in grain boundary. The as-fabricated Cu-15Ni-8Sn alloy exhibited yield strength of 522 MPa, ultimate tensile strength of 653 MPa, and elongation of 17%. The excellent mechanical performance of the as-fabricated Cu-15Ni-8Sn alloy is caused by the local laser melting mode including rapid cooling rate and reduplicative fusing from the subsequent layer melting, which leads to refined grains and limited Sn segregation in micron-size within the matrix. [ABSTRACT FROM AUTHOR]

Copper-Nickel-Tin (Cu-Ni-Sn) spinodally decomposable alloy of composition Cu-7Ni-4Sn was prepared by using sand casting process. The specimens required for microscopic examination, micro-hardness and wear tests were prepared from heat treated (homogenization, solution and ageing) cast rods. The microscopic examination results revealed that the as-cast dendrite structure was disappeared during the homogenization, solution and ageing processes and forms grains of various sizes with respect to ageing time. The hardness of the alloy was increased from 206 HV at solution treated condition to 235 HV at four hours of ageing. By using pin-on-disc wear tester in dry sliding condition an adhesive wear test was conducted as per L9 orthogonal array by taking parameters of applied load, sliding speed and ageing time. An optimum level of parameter for each case was determined through S/N ratio investigation by considering "smaller-the-better". From this investigation, it was found that the parameter ageing time was the dominant as compared to other two parameters. The significant parameter that affect the response was indicated by the results obtained from ANOVA and these results were agreed with S/N analysis. The developed linear regression equation was validated through confirmation experiments. The wear mechanism was observed on worn out surfaces by selecting appropriate specimens considering applied load and sliding speed for both normal and optimum parameter specimens using scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

Direct solution coating technique has emerged as a promising economically viable process for earth abundant chalcogenide absorber materials for photovoltaic applications. Here, direct ethanol based dip coating of earth abundant Cu 2 NiSnS 4 (CNTS) films on soda lime glass (SLG), molybdenum coated glass (Mo), and fluorine doped tin oxide coated glass (FTO) substrates is investigated. The structural and morphological properties of pre-annealed and sulfurized CNTS films coated on SLG, FTO, and Mo substrates are reported. The influence of dipping cycles on composition and optoelectronic properties of pre-annealed and sulfurized CNTS films deposited on SLG substrate is presented. Energy dispersive spectroscopy (EDS) and X-ray fluorescence (XRF) analysis reveal how changes in thickness and elemental composition affect morphology and optoelectronic properties. The obtained absorption coefficient, optical bandgap, resistivity and mobility of pre - annealed and sulfurized films are found to be 10 4 cm −1 , 1.5 eV, 0.48 Ωcm, 3.4 cm 2 /Vs and 10 4 cm −1 , 1.29 eV, 0.14 Ωcm, 11.0 cm 2 /Vs, respectively. These properties are well suited for photovoltaic applications and lead to the conclusion that the direct ethanol based dip coating can be an alternative economically viable process for the fabrication of earth abundant CNTS absorber layers for thin film solar cells. [ABSTRACT FROM AUTHOR]

Nanoporous networks of tin-based alloys immobilized within carbon matrices possess unique structural and compositional superiorities toward lithium-storage, and are expected to manifest improved strain-accommodation and charge-transport capabilities and thus desirable anodic performance for advanced lithium-ion batteries (LIBs). Herein, a facile and scalable hybrid aerogel-derived thermal-autoreduction route has been developed for the construction of nanoporous network of Sn Ni alloy immobilized within carbon/graphene dual matrices (Sn Ni@C/G network). When applied as an anode material for LIBs, the Sn Ni@C/G network manifests desirable lithium-storage performances in terms of specific capacities, cycle life, and rate capability. The facile aerogel-derived route and desirable Li-storage performance of the Sn Ni@C/G network facilitate its practical application as a high-capacity, long-life, and high-rate anode material for advanced LIBs. [ABSTRACT FROM AUTHOR]

Ni-30wt%Sn alloy powder beds were remelted using a laser beam to examine regular eutectic and anomalous eutectic growth behavior. The remelted microstructure mainly consisted of primary α-Ni dendrites and refined regular lamellar eutectic in the interdendrite space. At the top of the molten pool, the competition between primary α-Ni dendrites and the regular lamellar eutectic can be explained by the maximum interface temperature criterion. Anomalous eutectic was observed at the bottom of the molten pool. The remelting of primary α-Ni dendritic arms formed in the first laser remelting scan had an important effect on the formation of the anomalous eutectic in the second laser remelting scan. This effect led to the formation of globular α-Ni particles with similar Euler's angles in the anomalous eutectic. [ABSTRACT FROM AUTHOR]

We propose the optimal composition of a polyligand ammonium-chloride-fluoride electrolyte and a mode of electrolysis for the deposition of functional coatings formed by tin-nickel alloys. The tin-nickel alloy with a tin content of 65 wt.% and a nickel content of 35 wt.% proves to be the most promising for microelectronics in the case of its application instead of gold coatings. It is shown that the obtained coatings are suitable for soldering with the use of low-temperature solders and acid-free fluxes and for the ultrasonic spot welding. The electrolytic deposits of tin-nickel alloys are investigated as the anodes of lithium-ion batteries by the potentiodynamic and galvanostatic cycling methods. It is shown that the deposits obtained from an alkaline tartrate-trilonate electrolyte are characterized in the first cycles by a high specific capacity of up to 700 mA ∙ h/g. In the course of cycling, this parameter decreases to 500 mA ∙ h/g. The obtained tin-nickel alloys guarantee high densities of charge-discharge currents without mechanical fracture. [ABSTRACT FROM AUTHOR]

The transformations of a Cu-10wt%Ni-5.5wt%Sn alloy as a function of the aging time in the range from room temperature up to 600 °C have been followed by Differential Scanning Calorimetry (DSC). The results obtained have shown that this alloy undergone two overlapping exothermic phase transitions with DSC peaks at 208 °C and 305 °C, respectively, followed by an endothermic phase transformation with a DSC peak at 526 °C. The structural analysis by TEM, ED, EDX and XRD of the intermediates phases previously discriminated by DSC suggests that the first exothermic peak is associated to the spinodal decomposition of the sample, while the second one is associated to the segregation of a DO 22 (Cu x Ni 1−x ) 3 Sn tetragonal phase coherent with the α-Cu structure of the starting alloy. The endothermic peak has been associated to the precipitation of cubic DO 3 nanocrystals from the DO 22 phase previously formed. The microhardness measurements carried out in combination with the structural characterization demonstrate that the aging hardening of the alloy under study is exclusively due to the formation of the coherent DO 22 phase. The DO 22 → DO 3 transition leads to a dramatic drop of the hardness of the alloy. [ABSTRACT FROM AUTHOR]

A new approach is developed to fabricate single-crystal Sn solder joints with a line-type structure. The primary purpose is to investigate the diffusion characteristics of Ni in single-crystal Sn with four different grain orientations during electromigration. An interesting new experimental phenomenon that Ni 3 Sn 4 forms on the surfaces of single-crystal Sn with regularity occurs which should be attributed to the extremely anisotropic diffusion property of Ni in single-crystal Sn. Besides, the diffusion velocity of Ni in single-crystal Sn during electromigration is ranked as followed: (001)> (101)> (301)> (100). Experimental observations are in good agreement with kinetic analysis. [ABSTRACT FROM AUTHOR]

Microsegregation is influenced by many factors during solicitation while the coupling effects of some important factors have been dismissed. During directional solidification of Sn–36at.%Ni peritectic alloys under high temperature gradient, melting/solidification of both the primary and peritectic phase caused by temperature gradient zone melting has been observed. An analytical model has been proposed to analyze the effect of temperature gradient zone melting on microsegregation of interdendritic melt in peritectic alloys. The coupling influences of peritectic reaction, coarsening process and solid state back-diffusion have all been included in this model. Both the experimental and theoretical analyses have demonstrated that melting/solidification of both the primary and peritectic phase could be accelerated by temperature gradient zone melting during peritectic solidification. Thus, microsegregation of interdendritic melt is restricted by temperature gradient zone melting during peritectic solidification. The analytical model in the present work shows inherent consistence with our previous models. [ABSTRACT FROM AUTHOR]

The grain growth and thermal stability after recrystallization in as-solidified highly undercooled Ni-3at.%Sn alloy melt were investigated. As for undercooled Ni-3at.%Sn alloy, a transition from dendritic to granular crystals occurred when Δ T ≥Δ T * , which was induced by the plastic deformation of dendrites and subsequent recrystallization. On this basis, the subsequent grain growth and solute segregation accompanying recalescence were calculated by a recently proposed thermo-kinetic model, which showed close agreement with the experimental results. It is concluded that the grain growth process was interrelated to recalescence, solute trapping and solute segregation of Sn atoms captured by solute trapping, which was responsible for the reduction of grain boundary energy and improvement of thermal stability. [ABSTRACT FROM AUTHOR]

A systematic study on the phase transformation behavior in a polycrystalline Ni–Ti–Fe shape memory alloy is reported. The investigation was carried out through series of differential scanning calorimetry (DSC) tests on three different samples with distinctly different microstructures of the alloy processed through different thermo-mechanical routes. The applied procedures involved cold rolling and marforming (rolling in liquid nitrogen) followed by short annealing treatments to recover the cold worked microstructure. These treatments altered the microstructure in terms of grain size, misorientation (defects) and texture. Three different microstructures were generated through adopted deformation processes (i) lower degree of texture, (ii) textured and (iii) refined grains with texture. The influence of the microstructural parameters on the phase transformations in terms of transformation temperature (TT) and associated energy of absorption/release was investigated. Temperature of transformation (TT) between different samples was affected predominantly by the grain size difference while enthalpy of transformation (austenite ↔ martensite) was mainly due to differences in texture, stored energy and in-grain misorientation. Though the differences in TT and enthalpy were not very significant, these results form a guideline for microstructure tailoring of bulk scale manufacturing of these alloys. [ABSTRACT FROM AUTHOR]

Ni-Sn alloys have been prepared by electrodeposition technique on nickel net substrates from pyrophosphoric acid solution system. The morphology, chemical compositions and catalytic properties for hydrogen evolution reaction (HER) of the Ni-Sn alloys are found to be sensitive to the electrodepositing potentials, while the crystalline phases of the electrodeposits are almost unchanged regardless of the potentials according to the X-ray diffraction (XRD) results. The Ni-Sn alloy deposited at −1.5 V exhibits the hydrogen overpotential of 161 mV when the polarization current density of 300 mA cm −2 at 25 °C, which is lower than that of 341 mV for the Raney-Ni electrode. In addition, the Ni-Sn alloy shows high durability in 30 wt% KOH solution for at least 3 months. The results imply that the deposited Ni-Sn alloys can be applied in practical as cathode in industrial water electrolyzer. [ABSTRACT FROM AUTHOR]

Interfacial reactions in Sn/Ni-4.5 wt.%Si and Sn-Cu/Ni-4.5 wt.%Si couples at 250°C, and Sn-Ni-Si ternary phase equilibria at 250°C were investigated in this study. Ni-Si alloys, which are nonmagnetic, can be regarded as a diffusion barrier layer material in flip chip packaging. Solder/Ni-4.5 wt.%Si interfacial reactions are crucial to the reliability of soldered joints. Phase equilibria information is essential for development of solder/Ni-Si materials. No ternary compound is present in the Sn-Ni-Si ternary system at 250°C. Extended solubility of Si in the phases NiSn and NiSn is 3.8 and 6.1 at.%, respectively. As more Si dissolves in these phases their lattice constants decrease. No noticeable ternary solubility is observed for the other intermetallics. Interfacial reactions in solder/Ni-4.5 wt.%Si are similar to those for solder/Ni. Si does not alter the reaction phases. No Si solubility in the reaction phases was detected, although rates of growth of the reaction phases were reduced. Because the alloy Ni-4.5 wt.%Si reacts more slowly with solders than pure Ni, the Ni-4.5 wt.%Si alloy could be a potential new diffusion barrier layer material for flip chip packaging. [ABSTRACT FROM AUTHOR]

Experiments consisting of melting followed by thermal stabilization ranging from 0 to 6 h on Sn–36 at.%Ni peritectic alloy have been carried out in Bridgman-type furnace. Both primary Ni 3 Sn 2 and peritectic Ni 3 Sn 4 phases are intermetallic phases with narrow solubility in this peritectic alloy. A mushy zone is formed between the complete liquid zone and the non-molten zone due to imposed temperature gradient. The transport of atoms due to this temperature gradient cause extensive variations in both microstructure and melt concentration at the solid/liquid interface. Microstructure evolution and solute concentration field in the liquid at the mushy zone/liquid interface have been characterized. An analytical model is proposed to describe the melt concentration at the mushy zone/liquid interface in peritectic alloys during thermal stabilization. When both the remelting of primary α phase and solubilities of primary and peritectic phases are taken into consideration, the calculations show reasonable agreement with experimental results. [ABSTRACT FROM AUTHOR]

Sn–Ni peritectic alloys were directionally solidified using a Bridgman type directional solidification furnace. Microhardness ( Hv ) of both primary Ni 3 Sn 2 phase and peritectic Ni 3 Sn 4 phase and microstructure length scales including primary dendrite arm spacing λ 1 were measured as a function of growth rate. Dependency of microhardness on the solidification processing parameters and primary dendrite arm spacing ( λ 1 ) in the directionally solidified Sn–36 at.%Ni alloys were experimentally analyzed. The relationships between the solidification processing parameters (growth rate v and temperature gradient G ) and microhardness, and primary dendrite arm spacing and microhardness were obtained by linear regression analysis: for primary Ni 3 Sn 2 phase, Hv = 501.06 v 0.07 , Hv = 5896.3 λ 1 −0.42 ; for peritectic Ni 3 Sn 4 phase, Hv = 306.76 v 0.10 , Hv = 843.6 λ 1 −0.69 . It has been found that the values of λ 1 decreases with the increasing values of v while the values of microhardness ( Hv ) increase with growth rate under constant G . [ABSTRACT FROM AUTHOR]

Free eutectic growth and its competition with single-phase growth in solidification of undercooled near-eutectic alloys are not yet fully understood. In this paper, the historical development of eutectic growth models was reviewed. The LZ model of free eutectic growth was evaluated using recent data of eutectic growth velocities in an undercooled Ni81.3Sn18.7 eutectic composition. An excellent agreement was achieved between the LZ model and the data. Crystal growth velocities in off-eutectic Ni83Sn17 and Ni80Sn20 compositions were measured using a high-speed camera technique. The present data of the off-eutectic compositions and the recent data of the eutectic composition were modeled using the LZ model and the LKT/BCT model of free dendritic growth. The modeling revealed that the competition between the free eutectic growth and the single-phase growth is controlled by the highest interface temperature criterion. A coupled zone of the α-Ni-Ni3Sn eutectic was calculated using this criterion. The coupled zone agrees well with studies of solidified structures of undercooled samples. [ABSTRACT FROM AUTHOR]

The kinetics of triple-junctions (TJs) in eutectic solidification is modeled by the thermodynamic extremum principle (TEP). It consists of two parts. First, TJs as the interaction of interfaces follow the interface kinetics according to which the temperature and concentration at the TJs are determined. This interface part of TJ kinetics is closely related to the eutectic point in the kinetic phase diagram. Second, TJs have their specific kinetics according to which their morphology (e.g., the contact angles in two dimensions) is determined. Using a new solution of solute diffusion in liquid, the TJ kinetics is incorporated into the current lamellar eutectic growth model. The model is applicable to the concentrated alloy systems and can be extended to any kind of eutectics. Simulation results of the rapid solidification of a lamellar Ni5Si2-Ni2Si (γ- δ) eutectic show that both parts of TJ kinetics can play important roles in eutectic solidification and need to be considered to improve the current eutectic theory. [ABSTRACT FROM AUTHOR]

Based on first-principles calculations, the effects of various Ni concentrations on the structural, elastic, electronic and thermodynamic properties of hexagonal η-Cu6Sn5 compound have been systematically investigated. The results demonstrate that higher Ni concentration in the η-Cu6-xNixSn5 (x = 0, 0.5, 1, 1.5 and 2) leads to thermodynamically stable compounds, and Ni atoms preferentially occupy Cu2 + Cu1c sites forming the η-Cu4Ni2Sn5 compound. It is also found that the unit cell volume and lattice parameter of the 'a' axis decrease with increasing Ni concentration, which are consistent with the other experimental results. Furthermore, the polycrystalline elastic properties are obtained from single-crystal elastic constants. Our results indicate that the addition of Ni enhances the mechanical stability, brittleness, modulus and Debye temperatures of η-Cu6Sn5 compound. Analyzing the electronic structure and charge density distribution provides the explanation that Ni develops distinct bonding energy to Cu and Sn in the structure. [ABSTRACT FROM AUTHOR]

The effects of Cu substitution on the phase transitions and magnetocaloric effect of Mn50Ni40-xCuxSn10 Heusler alloys were investigated. With the increase of Cu content, the martensitic transformation (MT) temperature shifts substantially towards lower temperature, while the Curie temperature of austenite remains almost unchanged. The reverse MT temperature decreases from 180 to 171 K for Mn50Ni39Cu1Sn10 alloy as the magnetic field increases from 1 to 30 kOe. Under an applied magnetic field of 30 kOe, the maximum values of magnetic field induced entropy changes are 19.6, 28.9, and 14.2 J/kg K for x = 0, 1, and 2, respectively. The effective refrigerant capacities and hysteresis losses for these alloys were discussed in this paper. [ABSTRACT FROM AUTHOR]

Highlights: [•] Thermodynamic description of the Ni–Sn–Zn system was obtained. [•] Six isothermal sections were calculated. [•] Third constituents solubility in binary phases’ extensions were taken into account. [•] Good correlation between calculated and experimental data was obtained. [ABSTRACT FROM AUTHOR]

Objective: To describe the orthodontic treatment of a nongrowing 30-year-old woman with asymmetric severe skeletal Class II malocclusions (asymmetric Angle Class II), large overjet (16 mm), large overbite (8 mm), two congenially missing mandibular incisors (presenting a deciduous anterior tooth), and signs and symptoms of temporomandibular joint disorder (TMD). Materials and Methods: We used novel improved super-elastic Ni-Ti alloy wires (ISWs) combined with Ni-Ti alloy coil springs, power hooks, and a zygomatic implant as reinforced anchorage to provide a constant and continuous mild force to the dentition. Results: We successfully distalized maxillary molars, premolars, and retracted anterior teeth and corrected the asymmetric Angle Class II molar relationship using this system of zygomatic anchorage in conjunction with ISWs, Ni-Ti alloy open-coil springs, and crimpable power hook. The maxillary molars were distalized, and postero-occlusal relationships were improved to achieve Class I canine and molar relationships on both sides. Intrusion of the upper molars made the mandibular plane close. Ideal overbite and overjet relationships were established. Facial esthetics were improved with decreased upper and lower lip protrusion, and no symptoms of TMD were observed after treatment. Conclusion: The orthodontic treatment described here is a promising anchorage technique alternative to traditional techniques to improve severe skeletal Class II with TMD. [ABSTRACT FROM AUTHOR]

A new instrument used for treating femoral head osteonecrosis was recently proposed: the umbrella-shaped, Ni-Ti memory femoral head support device. The device has an efficacy rate of 82.35%. Traditional radiographic study provides limited information about the mechanical behaviour of the support device during an implant operation. Thus, this study proposes a finite element analysis method, which includes a 3-step formal head model construction scheme and a unique material assignment strategy for evaluating mechanical behaviour during an implant operation. Four different scenarios with different constraints, initial positions and bone qualities are analyzed using the simulation method. The max radium of the implanted device was consistent with observation data, which confirms the accuracy of the proposed method. To ensure that the device does not unexpectedly open and puncture the femoral head, the constraint on the impact device should be strong. The initial position of sleeve should be in the middle to reduce the damage to the decompression channel. The operation may fail because of poor bone quality caused by severe osteoporosis. The proposed finite element analysis method has proven to be an accurate tool for studying the mechanical behaviour of umbrella-shaped, Ni-Ti memory alloy femoral head support device during an implant operation. The 3-step construct scheme can be implemented with any kind of bone structure meshed with multiple element types. [ABSTRACT FROM AUTHOR]

Ni - Sn alloys were electrodeposited from acidic chloride-sulphate solution in potentiostatic and galvanostatic conditions. Cyclic voltammetry and Hull cell were used for the selection of the appropriate deposition potentials and cathodic current densities, respectively. In the potentiostatic conditions (-1.0 - -1.2 V vs. Ag/AgCl) porous deposits (~7-10 wt% Ni) were obtained, while dense coatings (~15-34 wt% Ni) were produced in the galvanostatic conditions (0.5-1.5 A/dm2). In both cases, deposits consisted of β - Sn and Ni3Sn4 phases. Speciation of the bath was also calculated. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effects of addition of Ge on the martensitic transition have been investigated. [•] Martensitic transition temperature can be tuned in a wide temperature range. [•] Martensitic transition temperatures decreased by about 7K at 30kOe for x =0.02. [•] The magnetic phase diagram was established. [•] Large magnetocaloric effect was obtained around martensitic transition temperature. [ABSTRACT FROM AUTHOR]

A very simple synthetic procedure was developed for the preparation of Ni-Sn alloy catalysts that were utilised for chemoselective hydrogenation of furfural, producing furfuryl alcohol almost exclusively. The mixture of nickel nanoparticles supported on aluminum hydroxide (R-Ni/AlOH) and a solution containing tin was treated under hydrothermal condition, producing the as prepared nickel-tin alloy supported on alumi-num hydroxide (Ni-Sn/AlOH). H2 treatment at range of temperature of 673-873 K for 1.5 h to the as prepared Ni-Sn/AlOH produced nanoporous Ni-Sn alloy catalysts. XRD patterns and SEM images revealed that the formation of Ni-Sn alloy of Ni3Sn and Ni3Sn2 phases and the transformation of crystalline gibbsite and bayerite into amorphous alumina were clearly observed after H2 treatment at 873 K. The formation of the Ni-Sn alloy may have played a key role in the enhancement of the chemoselectivity. [ABSTRACT FROM AUTHOR]

(Cu,Ni)Sn is an important intermetallic compound (IMC) in lead-free Sn-Ag-Cu solder joints on Ni substrate. The formation, growth, and microstructural evolution of (Cu,Ni)Sn are closely correlated with the concentrations of Cu and Ni in the solder. This study reports the interfacial behaviors of (Cu,Ni)Sn IMC (Sn-31 at.%Cu-24 at.%Ni) with various Sn-Cu, Sn-Ni, and Sn-Cu-Ni solders at 250°C. The (Cu,Ni)Sn substrate remained intact for Sn-0.7 wt.%Cu solder. When the Cu concentration was decreased to 0.3 wt.%, (Cu,Ni)Sn significantly dissolved into the molten solder. Moreover, (Cu,Ni)Sn dissolution and (Ni,Cu)Sn formation occurred simultaneously for the Sn-0.1 wt.%Ni solder. In Sn-0.5 wt.%Cu-0.2 wt.%Ni solder, many tiny (Cu,Ni)Sn particulates were formed and dispersed in the solder matrix, while in Sn-0.3 wt.%Cu-0.2 wt.%Ni a lot of (Ni,Cu)Sn grains were produced. Based on the local equilibrium hypothesis, these results are further discussed based on the liquid-(Cu, Ni)Sn-(Ni,Cu)Sn tie-triangle, and the liquid apex is suggested to be very close to Sn-0.4 wt.%Cu-0.2 wt.%Ni. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ni3Sn4 acts as a source of Ni atoms, leading to a strong cross-interaction with Pd. [•] (Cu,Ni)6Sn5 is an effective Ni diffusion barrier, inhibiting Pd resettlement. [•] Dissolution kinetics of (Pd,Ni)Sn4 was interpreted based on the Sn–Ni–Pd isotherm. [•] Cu addition to solder alleviates the (Pd,Ni)Sn4-related risk of reliability deterioration. [ABSTRACT FROM AUTHOR]

Highlights: [•] The anomalous eutectic was obtained in the bottom of the sample with the low laser scanning velocity of 0.1mm/s. [•] The free nucleation and rapid growth of eutectic should be a necessary condition for the formation of anomalous eutectic. [•] The microhardness of anomalous eutectic is lower than that of regular lamellar eutectic. [ABSTRACT FROM AUTHOR]

We study specific features of the formation of micro- and nanostructures in diamond−Fe-Cu-Ni-Sn-CrB composite materials obtained by sintering in the molds placed in a muffle furnace with subsequent hot post-pressing. We also clarify the mechanisms contributing to the improvement of the mechanical properties of these composites depending on the technological modes of their production. [ABSTRACT FROM AUTHOR]

Shapememory alloys (SMAs) are a relatively new class of functional materials, exhibiting special thermo mechanical behaviors, such as shapememory effect and superelasticity, which enable their applications in seismic engineering as energy dissipation devices. This paper investigates the properties of superelastic NiTi shape memory alloys, emphasizing the influence of strain rate on superelastic behavior under various strain amplitudes by cyclic tensile tests. A novel constitutive equation based on Graesser and Cozzarelli's model is proposed to describe the strain-rate-dependent hysteretic behavior of superelastic SMAs at different strain levels. A stress variable including the influence of strain rate is introduced into Graesser and Cozzarelli's model. To verify the effectiveness of the proposed constitutive equation, experiments on superelastic NiTi wires with different strain rates and strain levels are conducted. Numerical simulation results based on the proposed constitutive equation and experimental results are in good agreement. The findings in this paper will assist the future design of superelastic SMA-based energy dissipation devices for seismic protection of structures. [ABSTRACT FROM AUTHOR]

Abstract: The growth of NiSn4 is studied during the solidification of Sn–Ni alloys containing 0–0.45wt%Ni. Where past research has found metastable NiSn4 after solid state ageing of Ni–Sn couples, it is shown here that NiSn4 also forms during solidification as both a primary and a eutectic phase over a wide range of solidification conditions. The NiSn4 phase has crystal structure isomorphous to PtSn4 (oC20) and no evidence is found for NiSn4 being stable at solidification temperatures. Primary NiSn4 crystal growth was promoted by high cooling rates and a comparison of growth ledges on the facets of primary NiSn4 and Ni3Sn4 crystals suggests easier interface attachment kinetics for NiSn4. The Sn–NiSn4 eutectic grew under all solidification conditions used, with an orientation relationship that produces a low lattice disregistry at the interface plane and the same NiSn4 growth direction as that selected during free growth of primary NiSn4. In hyper-eutectic compositions, both the Sn–NiSn4 and Sn–Ni3Sn4 eutectics grew with the latter growing from primary Ni3Sn4 crystals. [Copyright &y& Elsevier]

A systematic study of the solidification mechanisms of binary Sn-Cu and ternary Sn-Cu-Ni alloys has been carried out. It is found that Sn-Cu is a weakly-irregular eutectic system with CuSn as the leading phase. Interestingly, two different eutectic morphologies (coarse and fine) are found to grow simultaneously during eutectic solidification. When the growth rate or composition is changed, the eutectic interface breaks down into a cellular eutectic with the fine eutectic in the center of the cells and the coarse one at the cell boundaries. The mechanisms responsible for these phenomena are discussed in conjunction with the beneficial effect of Ni additions to the Sn-Cu solder. [ABSTRACT FROM AUTHOR]

Abstract: Nickel–tin foams with a graded micro-porous framework and nano-porous walls are created by an electrochemical deposition method for use as the anode in rechargeable lithium batteries. The resulting electrodes react readily with lithium electrochemically and deliver a reversible capacity of more than 470mAhg−1 for up to 50 cycles. In addition, they show outstanding rate performance: their reversible capacity at a discharging rate of 20C is about 70% of the capacity at a rate of 1C, due mainly to their unique structure which allows facile lithium-ion transport and fast surface reactions. The reversible capacity and rate capability show strong dependence on the thickness of the deposit and this is associated with the accessibility of lithium ions inside the porous structure. [Copyright &y& Elsevier]

Abstract: The effect on substitution of Cu or P into the Ni–Sn intermetallic compound (IMC) is examined by analyzing the electronic structure based on first-principle calculation. When the Cu atom is substituted for the Ni one in Ni3Sn2, the resulting Ni–Cu–Sn IMC was energetically unstable, and then it had the higher electrical conductivity by the light electron effective mass. Meanwhile, when the P atom is replaced by the Sn one, the Ni–Sn–P IMC had the higher bulk modulus by the strong p–d hybridization between Ni and Sn or P, and also its electrical conductivity is lessen by the heavy electron effective mass. [Copyright &y& Elsevier]

Abstract: Nanocrystalline spinel ferrites with nominal composition Co0.5Mn0.5Fe2−2x Sn x Ni x O4 (x =0.0, 0.2, 0.4 and 0.6) are prepared by the co-precipitation method. The samples are characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (ED-XRF), dc electrical resistivity and hysteresis loops measurements. The powder XRD patterns confirm the single spinel phase and the crystallite size is found in the range of 17–18nm. The lattice constant (a), X-ray density (ρ X-ray) and porosity (P) are also calculated from XRD data. The elemental composition of the synthesized samples is determined by ED-XRF analysis. The dc electrical resistivity (ρ) of all samples is measured in the temperature range of 303–723K and is found to decrease with temperature, indicating the semiconducting nature of the synthesized materials. The room temperature electrical resistivity increases from 10.22 to 40.01×107 Ωcm with dopant concentration while the drift mobility (μ d) decreases from 21.3 to 1.42×10−12 cm2 V−1 S−1. The saturation magnetization (M s) increases from 18.33 to 38.39emug−1 up to x =0.2 and then decreases, while the coercivity (H c) decreases continuously with dopant concentration. The increase in the dc electrical resistivity and saturation magnetization make the synthesized materials suitable for their applications in microwave devices and high density recording media, respectively. [Copyright &y& Elsevier]

Abstract: Using quantitative differential scanning calorimetry (DSC) it was found that the amount of (β-Ti) developed during the sintering of pure Ni and Ti powders up to 900°C decreased from 50wt% in a 90μm Ni/Ti powder to only 3wt% in a 1.2μm Ni/Ti powder mixture. An additional isothermal hold step at 900, 940 or 950°C further reduced the (β-Ti) fraction. Analysis of the DSC data indicated that, at 900°C, a hold time of 204, 21, 6.6 and 0.7min would be required to completely remove (β-Ti) from a 90, 38, 10.7 and 1.2μm Ni/Ti mixture, respectively. In the case of the 90μm Ni/Ti mixture, increasing the hold temperature from 900 to 940 or 950°C resulted in a reduction in the (β-Ti) removal time from 204 to 137 and 86min, respectively. Removal of (β-Ti) from the microstructure eliminated melting at 942°C and thus avoided a combustion reaction and the large-scale porosity it produces. [Copyright &y& Elsevier]

Abstract: The interfacial evolution and shear strength of Sn3.8Ag0.7Cu–xNi composite solders on organic solderability preservative (OSP) finished pad were investigated at a temperature of 150°C aging for 0–1000h. It was found that all aged joints exhibited a duplex intermetallic compounds (IMCs) structure; i.e. a layer of (CuNi)6Sn5 close to the solder and a layer of Cu3Sn adjacent to the Cu substrate. The growth of the Cu3Sn layer was suppressed significantly after Ni particles addition, and the scallop-shape IMC with the composition of (CuNi)6Sn5 could be examined at the interface of all solder joints. In comparison with the non-composite joint, the IMC grain was refined significantly at the interface of composite joints. In addition, the mean thickness of interfacial IMC layers increased linearly with the square root of the aging time for all the diffusion couples. The Cu3Sn layer shows the fastest growth rate at the interface of non-composite. The fracture after the ball shear test occurred in the bulk solder for all as-reflowed joints and the aged SAC and SAC–0.5Ni joints. The fracture mode of SAC–1Ni and 2Ni joints transferred from an initial ductile type to a mixed type near the interface with the partial brittle fracture after 50h aging. [Copyright &y& Elsevier]

Abstract: The kinetics of the solid-state reactive diffusion in the (Sn–Ni)/Pd system was experimentally studied to examine the influence of Ni on the growth behavior of compounds at the interconnection between the Sn-base solder and the multilayer Pd/Ni/Cu conductor during energization heating. Diffusion couples composed of pure Pd and binary Sn–Ni alloys with y =0.01, 0.03 and 0.05 were prepared by a diffusion bonding technique, and then isothermally annealed at temperatures of T =453K and 473K for various times up to 325h. Here, y is the mol fraction of Ni in the Sn–Ni alloy. Owing to annealing, compound layers of (Pd, Ni)Sn4, PdSn4, PdSn3 and PdSn2 are formed at the (Sn–Ni)/Pd interface in the diffusion couple. The thickness is much smaller for the (Pd, Ni)Sn4, PdSn3 and PdSn2 layers than for the PdSn4 layer. Therefore, the growth of the compound layers is governed by PdSn4. The square of the total thickness l of the compound layers is almost proportional to the annealing time t as follows: l 2 = Kt, where K is the parabolic coefficient. This relationship is called the parabolic relationship. Since grain growth occurs at certain rates in the PdSn4 layer, the parabolic relationship guarantees that the growth of the compound layers is controlled by volume diffusion. At T =473K, K is insensitive to y. On the other hand, at T =453K, K remarkably decreases with increasing value of y, and reaches to the minimum at y =0.03. Such dependencies of K on y and T are attributed to the formation of (Pd, Ni)Sn4. Hence, the addition of Ni with y =0.03 into the Sn-base solder considerably suppresses the growth of compounds at the interconnection between the Sn-base solder and the multilayer Pd/Ni/Cu conductor during solid-state energization heating unless the heating temperature exceeds 453K. [Copyright &y& Elsevier]

To evaluate the effect of the substitution of the M-site atoms Ti, Zr, and Hf on thermoelectric properties, nearly single-phase (M,M)NiSn alloys (Ma, Mb = Hf, Zr, Ti) were fabricated by directional solidification. The lattice thermal conductivity can be most effectively reduced in the (Ti0.5,Hf0.5)NiSn alloy, probably due to the solid-solution effect, since the difference in atomic size and atomic mass are maximized between Ti and Hf. Moreover, we have found the phase separation between Ti-rich and Ti-poor half-Heusler phases in (Ti0.5,Hf0.5)NiSn and (Ti0.5,Zr0.5)NiSn alloys through observation of microstructure, chemical concentration measurement, and x-ray diffractometry. [ABSTRACT FROM AUTHOR]

Abstract: Fine size Sn–Ni alloy powders with spherical shape were directly prepared by spray pyrolysis. The alloy powders prepared at temperatures below 1200°C had bimodal size distributions of nano- and submicron-sized powders. Nano-sized powders were formed by chemical vapor deposition process from the evaporated Sn component. The powders had main peaks of Sn–Ni alloys irrespective of the preparation temperatures. Ni and Sn components are well dispersed inside the submicron-sized powders. The initial discharge capacity of the Sn–Ni alloy powders prepared at a temperature of 1100°C was 477mAh/g. However, the initial discharge capacity of the Sn–Ni alloy powders prepared at temperature of 1000 and 1200°C temperature were 255 and 411mAh/g respectively. The Sn–Ni alloy powders prepared at a temperature of 1100°C had more good cycle performance than those prepared at temperatures of 1000 and 1200°C. [Copyright &y& Elsevier]

Abstract: Electroless plating technique was used to coat Sn–Ni alloy on copper substrate with high Sn content by adding the amounts of thiourea as special complexing agent and sodium hypophosphite as reducing agent to an acidic electroless plating bath of SnCl2 and NiCl2, which avoided activation pretreatment in plating process. The Sn content of the Sn–Ni layer increased with lowing temperature which reached 60wt.% under optimum plating conditions. The effect of thiourea and sodium hypophosphite amount, plating temperature, and the acidity of plating bath was also discussed in this article. The corrosion-resistance properties of Sn–Ni alloy layer proved to be good by testing the anodic polarization curves of the alloy layer. [Copyright &y& Elsevier]

Abstract: A three-dimensionally ordered macroporous (3DOM) Ni–Sn alloy electrode was prepared by electroplating using a colloidal crystal template consisting of monodisperse polystyrene (PS) latex. Scanning electron microscopy observations revealed that the prepared 3DOM Ni–Sn electrode (thickness: 16μm) had uniform macropores that were 1.0μm in diameter. The feasibility of using this electrode as the anode in an organic electrolyte for lithium batteries was examined. Although the 3DOM Ni–Sn electrode exhibited a discharge capacity of 455mAhg−1, the discharge capacity decreased rapidly after 30 charge–discharge cycles owing to the collapse of the porous structure caused by the volume change during lithiation and delithiation. [Copyright &y& Elsevier]

Abstract: The crystallographic and magnetic structures of Er6Ni2Sn have been determined at low temperatures using neutron powder diffraction. It has been found that this system orders antiferromagnetically (AF) below T N =17K. Data taken at low temperatures and analyzed using symmetry group analysis suggest that Er6Ni2Sn forms a complex non-collinear commensurate AF structure with strongly reduced Er magnetic moments. The reason for the reduced moments is unclear and needs further studies. The magnetic phases below 7K and in the temperature range 7–17K differ only in the Er magnetic moment magnitudes and in the angle that the Er moments at the 8l site make with the c-axis. The extra reflections present in the powder diffraction patterns suggest presence of a secondary phase. The temperature evolution of the powder pattern indicates that the secondary phase orders AF at 35K. [Copyright &y& Elsevier]