Cu-Sn Alloy Research Articles

Influence of Copper-Iron (CuFe) and Copper-Tin (CuSN) alloys over mechanical strength properties in crimping process

This study investigates the comparative performance of Copper-Iron (CuFe) and Copper-Tin (CuSn) alloys in crimping processes, with a focus on their mechanical, electrical, and corrosion-resistance properties. Crimping is a critical method for creating reliable electrical and mechanical connections, particularly in environments subjected to significant mechanical stress and varying temperatures [1]. CuFe alloys, known for their superior mechanical strength and hardness, present challenges in crimping due to their increased resistivity and reduced ductility. Conversely, CuSn alloys offer a balance between electrical conductivity, ease of crimping, and corrosion resistance, making them a preferred choice in many industrial applications. This research aims to provide a comprehensive analysis of how the distinct properties of CuFe and CuSn alloys influence the crimping process, ultimately guiding material selection for optimized performance in various applications [2]. Experimental data will be drawn from tensile strength tests, electrical resistance measurements, and corrosion tests, providing a holistic understanding of the advantages and limitations of each alloy.

In situ p-block protective layer plating in carbonate-based electrolytes enables stable cell cycling in anode-free lithium batteries.

'Anode-free' Li metal batteries offer the highest possible energy density but face low Li coulombic efficiency when operated in carbonate electrolytes. Here we report a performance improvement of anode-free Li metal batteries using p-block tin octoate additive in the carbonate electrolyte. We show that the preferential adsorption of the octoate moiety on the Cu substrate induces the construction of a carbonate-less protective layer, which inhibits the side reactions and contributes to the uniform Li plating. In the mean time, the reduction of Sn2+ at the initial charging process builds a stable lithophilic layer of Cu6Sn5 alloy and Sn, improving the affinity between the Li and the Cu substrate. Notably, anode-free Li metal pouch cells with tin octoate additive demonstrate good cycling stability with a high coulombic efficiency of ~99.1%. Furthermore, this in situ p-block layer plating strategy is also demonstrated with other types of p-block metal octoate, as well as a Na metal battery system, demonstrating the high level of universality.

Geometrical features, stability and electronic properties of (Cu3Sn)n clusters

Recently, significant advancements have been made in low-entropy Cu3Sn catalysts, showcasing their efficient catalytic CO oxidation capabilities. Hence, the atomic models of the Cu3Sn are worth established to further investigate their catalytic mechanisms. Here, the structural features and stability of (Cu3Sn)n clusters (n = 1–6) are investigated using the genetic algorithm combined with the density functional theory (DFT). The results reveal the structural evolution of these clusters from hollow cages to compact icosahedrons, where Cu atoms predominantly tend to grow together, while Sn atoms are dispersed at the edge positions. The Eb, Ef and Δ2E analyses show that the icosahedral (Cu3Sn)3 has a higher stability than that of its neighbors. The molecular dynamics simulations demonstrates its stability even at 1000 K. The molecular orbitals and density of states reveal that the (Cu3Sn)3 has an 1S21P61D102S21F1 superatomic electronic configuration. Electrostatic potential surfaces show that (Cu3Sn)n clusters have significant σ-hole regions at the Cu atomic sites, which can make the CO stretching frequency and bond length have a large red-shift. Moreover, the adsorption energy between the (Cu3Sn)3 and CO is the largest, reaching 1.17 eV. Our work provides inferences to the structural characteristics and adsorptions of the CuSn alloys at the atomic level.

Enhanced Charge-Carrier Dynamics and Efficient Photoelectrochemical Nitrate-to-Ammonia Conversion on Antimony Sulfide-Based Photocathodes.

The photoelectrochemical reduction of nitrate to ammonia (PEC NO3RR) has emerged as a promising pathway for facilitating the natural nitrogen cycle. The PEC NO3RR can lower the reduction potential needed for ammonia synthesis through photogenerated voltage, showcasing the significant potential for merging abundant solar energy with sustainable nitrogen fixation. However, it is influenced by the selective photocathodes with poor carrier kinetics, low catalytic selectivity, and ammonia yields. There are few reports on suitable photoelectrodes owning efficient charge transport on PEC NO3RR at low overpotentials. Herein, we rationally constructed the CuSn alloy co-catalysts on the antimony sulfides with a highly selective PEC ammonia and an ultra-low onset potential (0.62 VRHE). CuSn/TiO2/Sb2S3 photoelectrodes achieved an ammonia faradic efficiency of 97.82 % at a low applied potential of 0.4 VRHE, and an ammonia yield of 16.96 μmol h-1 cm-2 at 0 VRHE under one sun illumination. Dynamics experiments and theoretical calculations have demonstrated that CuSn/TiO2/Sb2S3 has an enhanced charge separation and transfer efficiency, facilitating photogenerated electrons to participate in PEC NO3RR quickly. Meanwhile, moderate NO2* adsorption on this photocathode optimizes the catalytic activity and increases the NH4 + yield. This work opens an avenue for designing sulfide-based photocathodes for the efficient route of solar-to-ammonia conversion.

Mystical alkali metal flame: Sodiophilic insights into rapid preparation of the Na metal battery anode

Extensive research has explored the utilization of tin oxide (SnO2) as a sodiophilic reagent in sodium metal batteries. However, achieving rapid encapsulation of sodium has remained elusive, despite efforts such as converting a side reaction yielding a sodiophobic Cu-Sn alloy into sodiophilic SnO2 on the Cu current collector's surface. Notably, the presence of preserved crystal water in SnO2 has proven pivotal, as it initiates the formation of a plasma-like alkali metal flame, facilitating swift encapsulation of metallic sodium at 400 °C. Analysis through XPS and TEM tests unveiled the interaction between crystal water and liquid sodium metal, leading to rapid heat release. This phenomenon results in the generation of sodium metal vapor (>882.9 °C) and the extraction of oxygen atoms from SnO2, forming Na2O within an argon environment. Consequently, Na2O, produced by the reaction of sodium and SnO2 with crystal water as the inducer, plays a critical role in the rapid encapsulation of sodium metal. Furthermore, the synthesized sodium metal electrode exhibited exceptional stability in cycles and resistance to dendrites. This discovery provides valuable insights into the reaction mechanisms of sodiophilic sites in sodium metals, serving as a crucial guide for further research in the field.

Improved electrochemical performance of Cu-Sn/nano-SiO2 composite anode materials for lithium-ion batteries fabricated by controlled electrodeposition

Cu-Sn/nano-SiO2 composite materials are fabricated through electrodeposition process coupled with precise thermal treatment, which employs hexadecyl trimethyl ammonium bromide to guarantee the even distribution of nano-SiO2 particles within the Cu-Sn alloy framework. The characterization results indicate that integrating nano-SiO2 into the Cu-Sn matrix effectively prevents active particles from detaching from the copper foil current collector. By adjusting the current density, the electrochemical performance of the Cu-Sn/nano-SiO2 composite electrode is significantly enhanced. Specifically, the initial charge and discharge specific capacities of the composite electrolyte are approximately 746.6 and 1470.8 mAh/g at 100 mA/g, respectively. Moreover, the cell can still maintain a discharge specific capacity of 358.6 mAh/g after 100 cycles. Furthermore, the cell demonstrates an improved lithium-ion diffusion coefficient of approximately 9.639 × 10–15 cm²/s and a lower transfer resistance of 54.65 Ω. Therefore, a direct approach of fabricating the Cu-Sn/nano-SiO2 composite electrode with enhanced electrochemical properties may provide valuable guidance for alloy anodes in the energy storage field.

Investigation of the Influence of Alloy Atomic Doping on the Properties of Cu-Sn Alloys Based on First Principles

In order to design Cu-Sn alloys with excellent overall performance, the structural stability, mechanical properties, and electronic structure of X-doped Cu-Sn alloys were systematically calculated using first-principles calculations. The calculation results of the cohesive energy indicate that the Cu-Sn-X structures formed by X atoms (X = Ag, Ca, Cd, Mg, Ni, Zr) doping into Cu-Sn can stably exist. The Cu-Sn-Ni structure is the most stable, with a cohesive energy value of −3.84 eV. Doping of X atoms leads to a decrease in the bulk modulus, Possion’s ratio and B/G ratio. However, doping Ag and Ni atoms can improve the shear modulus, Young’s modulus, and strain energy of the dislocation. The doping of Ni has the highest enhancement on shear modulus, Young’s modulus, and strain energy of the dislocation, with respective values as follows: 63.085 GPa, 163.593 GPa, and 1.689 W/J·m−1. The analysis of electronic structure results shows that the covalent bond between Cu and X is the reason for the performance differences in Cu-Sn-X structures.

An Examination of Bronze Vessel Technology in the Unified Silla Period: Case Study on the Bronzes Excavated from Gwanbuk-ri Site in Buyeo

Archaeological excavations in Buyeo had revealed Bronze vessels interred within a hole in the building at the Gwanbuk-ri site. These bronze vessels are dated to the Unified silla period (9-10th centuries). To identify the bronze vessels’ manufacturing technology, metallurgical analyses were carried out using Optical Microscopy, SEM-EDS and EPMA. The results allowed a reconstruction of the manufacturing process of bronze vessels in the Unified silla. It proved that bronze vessels were manufactured with Cu-Sn alloy with varying tin contents, which may be related to the application of uncontrolled procedures in making the bronze alloys. Also a casting process was used to shape the bronze vessels and the strength and hardness of the container were improved through a quenching process. Twins were observed in one of the samples, so it was assumed that hot working had been attempted. Non-metallic inclusions in bronze vessels have circular or polygonal shapes, and Cu and S were detected. The presence of Cu-S inclusions showed the probable use of copper sulphide ores for metal production and smelting. Se and Te in the inclusions of the bronze vessels show that the copper ore is different. From the results of metallurgical analyses of bronze vessels excavated from other regions of the same era, casting and quenching treatments were confirmed, and the sequential relationship of the technological system was revealed.

Direct Electrocatalytic Reduction of As(III) on CuSn Alloy Electrode: A Green and Sustainable Strategy to Recover Elemental Arsenic from Arsenic Wastewater

Direct Electrocatalytic Reduction of As(III) on CuSn Alloy Electrode: A Green and Sustainable Strategy to Recover Elemental Arsenic from Arsenic Wastewater

Unveiling the Role of Ge in CZTSSe Solar Cells by Advanced Micro-To-Atom Scale Characterizations.

Kesterite is an earth-abundant energy material with high predicted power conversion efficiency, making it a sustainable and promising option for photovoltaics. However, a large open circuit voltage Voc deficit due to non-radiative recombination at intrinsic defects remains a major hurdle, limiting device performance. Incorporating Ge into the kesterite structure emerges as an effective approach for enhancing performance by manipulating defects and morphology. Herein, how different amounts of Ge affect the kesterite growth pathways through the combination of advanced microscopy characterization techniques are systematically investigated. The results demonstrate the significance of incorporating Ge during the selenization process of the CZTSSe thin film. At high temperature, the Ge incorporation effectively delays the selenization process due to the formation of a ZnSe layer on top of the metal alloys through decomposition of the Cu-Zn alloy and formation of Cu-Sn alloy, subsequently forming of Cu-Sn-Se phase. Such an effect is compounded by more Ge incorporation that further postpones kesterite formation. Furthermore, introducing Ge mitigates detrimental "horizontal" grain boundaries by increasing the grain size on upper layer. The Ge incorporation strategy discussed in this study holds great promise for improving device performance and grain quality in CZTSSe and other polycrystalline chalcogenide solar cells.

Structure regulated CuSn alloy catalyst for selective electrochemical CO2-to-formate conversion at higher current densities

CuSn alloy electrocatalysts have shown a promising CO2 electroreduction performance towards formate production. However, it is still a big challenge for the electrode to achieve superior selectivity towards formate at a current density over hundreds of mA cm−2. Herein, a CuSn alloy catalyst with predominant electrochemical CO2-to-formate conversion was designed. With a unique dendritic-like structure, CuSn4 (prepared at current density of 4 A cm−2) exhibited a maximum faradaic efficiency (FEformate) of 82.1 %, and the FEformate could be maintained over 80 % with the partial current density close to −200 mA cm−2. Mechanism analysis unveiled that the dendritic structure of CuSn4 induced higher CO2 concentration around the reaction sites. Meanwhile, the higher electric density due to the unique structure and the generated Sn (II) species lowered the binding energy of CO2− intermediate. Such a structure and Sn (II)-enriched interfaces could be stably maintained and sustainably generated as a result of “natural oxidation-CO2 reduction”. This study presents a straightforward approach to develop an efficient electrode for CO2-to-formate conversion at higher current densities.

Electrochemical performance of Cu6Sn5 alloy anode materials for lithium-ion batteries fabricated by controlled electrodeposition.

Combining electrodeposition and heat treatment is an effective method to successfully fabricate Cu6Sn5 alloy materials, in which the S2 alloy electrode is electrodeposited at 1.2 A dm-2 current density with uniform and compact morphology. The characterization results show that monoclinic η'-Cu6Sn5 and hexagonal η-Cu6Sn5 phases fabricated at the appropriate current density exhibit excellent electrochemical performance. The optimal Cu6Sn5 alloy anode material boasts not just a significantly high discharge specific capacity of 890.2 mA h g-1 with an initial coulombic efficiency (ICE) of 73.96%, but also achieves an adequate discharge specific capacity of 287.1 after 50 cycles at 100 mA h g-1. Moreover, the electrodeposited Cu6Sn5 alloy materials also possessed a lower transfer resistance of 42.45 Ω and an improved lithium-ion diffusion coefficient of 2.665 × 10-15 cm2 s-1 at the current density of 1.2 A dm-2. Therefore, preparing the Cu6Sn5 alloy thin-film electrode could be a cost-effective and straightforward method by electrodeposition from cyanide-free plating baths to develop anode components suitable for lithium-ion battery applications.

Bending Strength Prediction of the Cu-Sn Alloy Through a Visual Quantization Model Integrated With Microstructure Characterization and Machine Learning

Bending Strength Prediction of the Cu-Sn Alloy Through a Visual Quantization Model Integrated With Microstructure Characterization and Machine Learning

New generation copper-based interconnection from nanoporous CuSn alloy film sintered at low temperatures

Two-step routine for the synthesis of nanoporous CuSn alloy material enabling joint formation in electronic packaging by sintering at 180 °C.

Material property control of CuSn alloy using wire and arc additive manufacturing (Translated)

Material property control of CuSn alloy using wire and arc additive manufacturing (Translated)

Thermodynamic phase control of Cu-Sn alloy electrocatalysts for selective CO2 reduction.

In the electrochemical CO2 reduction reaction (CO2RR), Cu alloy electrocatalysts can control the CO2RR selectivity by modulating the intermediate binding energy. Here, we report the thermodynamic-based Cu-Sn bimetallic phase control in heterogeneous catalysts for selective CO2 conversion. Starting from the thermodynamic understanding about Cu-Sn bimetallic compounds, we established the specific processing window for Cu-Sn bimetallic phase control. To modulate the Cu-Sn bimetallic phases, we controlled the oxygen partial pressure (pO2) during the calcination of electrospun Cu and Sn ions-incorporated nanofibers (NFs). This resulted in the formation of CuO-SnO2 NFs (full oxidation), Cu-SnO2 NFs (selective reduction), Cu3Sn/CNFs, Cu41Sn11/CNFs, and Cu6Sn5/CNFs (full reduction). In the CO2RR, CuO-SnO2 NFs exhibited formate (HCOO-) production and Cu-SnO2 NFs showed carbon monoxide (CO) production with the faradaic efficiency (FE) of 65.3% at -0.99 V (vs. RHE) and 59.1% at -0.89 V (vs. RHE) respectively. Cu-rich Cu41Sn11/CNFs and Cu3Sn/CNFs enhanced the methane (CH4) production with the FE of 39.1% at -1.36 V (vs. RHE) and 34.7% at -1.50 V (vs. RHE). However, Sn-rich Cu6Sn5/CNFs produced HCOO- with the FE of 58.6% at -2.31 V (vs. RHE). This study suggests the methodology for bimetallic catalyst design and steering the CO2RR pathway by controlling the active sites of Cu-Sn alloys.

Effect of Cu-coated diamond on the formation of Cu–Sn-based diamond composites fabricated by laser-powder bed fusion

In this study, Cu–Sn-based diamond composites were fabricated using L-PBF. The effects of the Cu-coated diamond on the melt-pool evolution, diamond–metal matrix bonding, thermal damage, and friction behavior of Cu in the Cu–Sn-based diamond composites were investigated. Moreover, the optimum L-PBF parameters for processing Cu-coated diamond/Cu–Sn composites were investigated. A convolutional neural network based on deep learning was used to process laser-scanned diamond images and evaluate the diamond thermal damage by model-feature visualization. The thermally damaged Cu-coated diamond and percentage of severely damaged parts were reduced compared to those of the uncoated diamond. Thick Cu coating changed the wettability of the diamond and matrix, thereby increasing the friction of the molten pool and unmelted metal particles and introducing the friction of the Cu microfluidic flow on the diamond. Hence, the mechanical holding force of the CuSn alloy matrix on the diamond substantially increased, and the bending strength of the Cu-coated diamond/Cu–Sn composites fabricated using L-PBF reached 720 MPa, which is approximately twice that of diamond/Cu–Sn (365 MPa).

Effect of Bi Content on the Microstructure, Mechanical and Tribological Properties of Cu-Sn Alloy.

To reduce the use of the toxic Pb element in the Cu-Sn alloy with high friction performance, Cu-xBi-10Sn alloys with different Bi contents were prepared by gravity casting, and the effect of Bi content on the microstructure, mechanical properties and wear property of Cu-Sn alloys were studied. The results showed that the Bi element was distributed in bands or long strips on the dendritic arms and did not form compounds with other elements. With the increase in Bi content, the hardness and tensile strength of Cu-xBi-10Sn alloys present a trend of increasing first and then decreasing. When the Bi content was 7 wt.%, the maximum hardness value was obtained, and the ultimate tensile strength was close to that of Cu-10Pb-10Sn alloy. Compared with Cu-10Pb-10Sn alloy, Cu-7Bi-10Sn alloy also possessed better friction reduction and wear resistance under the oil lubrication condition.

Zn additions modifying microstructure, thermal parameters and cytotoxicity of Sn-0.7Cu eutectic solder alloys

Alloys from the SnCu systems have superior properties as compared to the SnPb alloys, such as mechanical and corrosion resistance. However, SnCu alloys still exhibit low oxidation resistance, poor wettability and low reliability. One way to optimize such properties is by adding alloying elements, such as zinc. Zn is generally used in Pb-free solder alloys to minimize intermetallic compound growth in soldered joints, refine the microstructure and increase mechanical strength, in addition to reducing the final cost. The addition of Zn is motivated by the effects it promotes such as microstructural refining, suppression of intermetallics in the substrate/alloy reaction layer, increase in fluidity and mechanical properties. Therefore, this study aims to understand the effects of Zn additions (0.2 and 0.5 in wt%) on solidification thermal parameters (growth rate-V and cooling rate-Ṫ), macrostructure, microstructure, phase transformation, macrosegregation and cytotoxicity in directionally solidified eutectic Sn-0.7wt.%Cu alloy under transient heat flow regime of solidification in copper sheet. Thus, the samples have been characterized by Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). The CALPHAD (CALculation of PHAse Diagrams) method by Thermo-calc software was used to generate property diagrams and isopleths. Cytotoxicity analysis was performed based on cell viability with incubation periods of 15 and 30 days for the alloys, with subsequent exposures of the extracts for 24 and 48 h. The Zn additions caused slight changes in the phase transformation temperatures of the Sn-Cu-Zn alloys. Macrostructures exhibiting columnar-to-equiaxed transition (CET) were observed for the Sn-Cu-Zn alloys. The microstructures of the Sn-Cu-Zn alloys were predominantly dendritic with a matrix rich in tin (β-Sn) surrounded by a eutectic mixture of the β-Sn + Cu6Sn5 + CuZn phases. After CET on Sn-Cu-Zn castings, low velocity eutectic cells have been observed. Moreover, Zn additions refined and did not change the dendritic arrangement of the Sn-Cu-Zn alloys, when compared to the Sn-0.7wt.%Cu alloy. However, increasing the Zn content did not affect the microstructural scale in the ternary alloys when compared to each other. The variations in the microstructural scale did not influence the toxicity of the examined alloys, but factors such as incubation time and chemical composition did. In general, Zn improved the cell viability of the Sn-Cu-Zn alloys, but still with moderate cytotoxic levels.

Effect of B on the microstructure and mechanical properties of Cu–Cu joints with in-situ Ag–Cu–Zn–Sn filler metal

With the development of advanced manufacturing, traditional Ag-based filler metals cannot reconcile the contradiction between high performance and complex processing. It also unable to meet the requirements of new materials, new structures and new processes for brazing connection performance. In this paper, based on the Ag–Cu–Zn–Sn flux-cored filler metal, the effect of the addition of B on the microstructure and mechanical properties of Cu–Cu brazing joints was investigated using FESEM‒EDS, EPMA, EBSD, TEM, microindenter and universal tensile testing machine. The results indicated that the microstructure in the brazing seam was mainly composed of Ag (s.s), Cu(s.s) and (Ag + Cu) eutectic. With increasing B content, the grain size and texture strength of Ag(s) and Cu(s) gradually decreased. The refinement of Ag-rich dendrites was mainly due to the enrichment of B atoms around the dendrite, which limited the diffusion of solute atoms in the melt and the release of solidification latent heat in front of the liquid‒solid interface, further inhibiting the growth of Ag-rich dendrites. The refinement behavior of Cu-rich dendrites was mainly attributed to the increase in B content, which reduced the tip radius of Cu-rich dendrites. The mass transfer path of B → B2O3 and B → liquid CuSn alloy → mixed melt of CuSn alloy + solder skin alloy → liquid filler metal in the brazed joint → Cu rich phase and grain boundary in the brazed joint → Ag rich phase and grain boundary in the brazing seam was clarified. The addition of B can improve the microhardness of the brazing seam. The shear strength reached a maximum value of 237.2 MPa when B was added at 2%. The fracture models mainly included intergranular fracture, dimple fracture and cleavage fracture. The strength of brazed joints can be improved by solid solution strengthening, process hardening strengthening and fine grain strengthening. The tangle and jog of dislocations within the crystal, the presence of a large number of grain boundaries and B-rich areas can prevent crack tip extension and enhance the toughness of brazing joints.