Brass Foil Research Articles

Single Exposed Zn (0002) Plane and Sustainable Zn‐Oriented Growth Achieving Highly Reversible Zinc Metal Batteries

To prevent dendrite growth and hydrogen evolution reaction, directional epitaxial growth of Zn2+ ions on Zn anode, especially along the lowest‐surface‐energy Zn (0002) plane, is pursued for highly reversible zinc metal batteries (ZMBs). However, designing single Zn (0002) exposed anodes for sustained uniaxial crystalline orientation of Zn electroplating faces challenges. Herein, we propose an anode engineering that utilizes a low lattice mismatch substrate and ordered Zn2+ migration channels to modify Zn anodes with single (0002) surface exposure and sustainable Zn‐oriented growth, yielding highly reversible ZMBs. A vapor‐deposited metal‐organic framework Cu3(C6O6)2 film on brass foil shows low lattice mismatch (4.24%) with electrodeposited Zn anodes, enabling the exposure of a single (0002) plane. Furthermore, the low desolvation energy (−1.36 eV) between solvated Zn2+ ions and the ordered porous Cu3(C6O6)2 film guides sustainable Zn‐oriented nucleation along the Zn (0002) surface. Consequently, the Zn||Zn cells with brass‐Cu3(C6O6)2 substrate shows a high average Coulombic efficiency of 99.55% after 4,000 cycles at 10 mA cm−2. This work provides a new window to design highly reversible Zn metal anode with a single‐exposed Zn (0002) plane and sustainable oriented growth for emerging ZMBs.

Single Exposed Zn (0002) Plane and Sustainable Zn‐Oriented Growth Achieving Highly Reversible Zinc Metal Batteries

To prevent dendrite growth and hydrogen evolution reaction, directional epitaxial growth of Zn2+ ions on Zn anode, especially along the lowest‐surface‐energy Zn (0002) plane, is pursued for highly reversible zinc metal batteries (ZMBs). However, designing single Zn (0002) exposed anodes for sustained uniaxial crystalline orientation of Zn electroplating faces challenges. Herein, we propose an anode engineering that utilizes a low lattice mismatch substrate and ordered Zn2+ migration channels to modify Zn anodes with single (0002) surface exposure and sustainable Zn‐oriented growth, yielding highly reversible ZMBs. A vapor‐deposited metal‐organic framework Cu3(C6O6)2 film on brass foil shows low lattice mismatch (4.24%) with electrodeposited Zn anodes, enabling the exposure of a single (0002) plane. Furthermore, the low desolvation energy (−1.36 eV) between solvated Zn2+ ions and the ordered porous Cu3(C6O6)2 film guides sustainable Zn‐oriented nucleation along the Zn (0002) surface. Consequently, the Zn||Zn cells with brass‐Cu3(C6O6)2 substrate shows a high average Coulombic efficiency of 99.55% after 4,000 cycles at 10 mA cm−2. This work provides a new window to design highly reversible Zn metal anode with a single‐exposed Zn (0002) plane and sustainable oriented growth for emerging ZMBs.

Ultrasonic vibration-assisted electrical discharge machining of enclosed microgrooves with laminated electrodes

An enclosed microgroove is a vital surface microstructure that is difficult to prepare on the surfaces of difficult-to-machine electrically conductive materials using conventional methods. Electrical discharge machining (EDM) is suitable for this task. It is obtained primarily through layer-by-layer scanning EDM with micro-column electrodes or reciprocating EDM with foil electrodes. However, owing to the small cross-sectional size of the electrodes, a stable machining process is challenging to achieve, which seriously reduces the machining efficiency. To solve these problems, this study proposed ultrasonic vibration-assisted EDM using a laminated electrode possessed strong anti-interference properties for enclosed microgrooves. The effects of ultrasonic vibration on the EDM of microgrooves with single foil and laminated electrodes were investigated. The results show that ultrasonic vibration could improve the machining efficiency of the two types of electrodes and significantly improve the profile quality of the microgrooves prepared using laminated electrodes. When the amplitude was 3 μm and the frequency was 30 kHz, the bottom sidewall corner radius of microgrooves machined by brass foils in laminated electrodes was 28 μm, the width, depth, and roughness of microgrooves machined by copper foils in laminated electrodes were approximately 78 μm, 229 μm and 0.7 μm, the material removal rate was 0.0072 mm3/min. Based on the optimized parameters, inverted “convex” microgrooves with fine consistency were successfully prepared using laminated electrodes on Ti–6Al–4V alloy surfaces. The machining time was reduced by 40% for each microgroove compared with using the single foil electrode. This study provides a new method for preparing complex microgrooves.

Experimental study on electrode wear during the EDM of microgrooves with laminated electrodes consisting of various material foils

Electrode wear during electrical discharge machining (EDM) is inevitable, and tool electrodes of different materials exhibit different wear rates. Unlike a single-material tool electrode, for a laminated electrode consisting of various material foils (LE-VMF), the components suffer from significantly different amounts of wear and also influence each other in EDM, however, the form and cause of the wear are not clear. Thus, the LE-VMFs including symmetric and asymmetric LE-VMFs were prepared and used in EDM in this paper. The wear of foils in LE-VMFs and their mutual influence during the EDM process were investigated through experiments. The wear forms of a single foil electrode and a foil of the same material in the LE-VMF were also compared. The experimental results show that copper foil with a lower wear rate had a protective effect on an adjacent brass foil with a larger wear rate in the LE-VMF, while the protective effect of the brass foil in the symmetric LE-VMF was larger than that in the asymmetric LE-VMF. The closer the distance from the copper foil, the stronger was the protection effect and the smaller was the wear. In addition, the working surface of the brass foil in the LE-VMF did not show any concavity-like wear in the middle region of its thickness after EDM, as was the case for the single brass foil electrode, even if the thickness of the brass foil was greater than 150 μm.

Competitive Roles of Conductivity and Lithiophility in Composite Lithium Metal Anode

For the three-dimensional conductive host, the uneven lithium deposition and the dependence on the pore structure and lithiophility are a great challenge for lithium metal anodes. Herein, we employed facial chemical etching techniques on brass foil to fabricate three-dimensional copper hosts with diverse pore structures and lithiophilities, thus intending to understand the lithium depositing mechanisms in porous hosts. The copper host with a more pronounced pore structure exhibits the lower polarization voltage induced by its large specific surface area, which reduces the local current density and provides a great deal of pathway for lithium ion diffusion. Meanwhile, it exhibits high nucleation overpotential and a short lifespan due to a reduced number of favorable lithium nucleation sites caused by the reduced lithiophilic zinc sites and a marked increase in the routes between nucleation sites. Therefore, the appropriate pore structure needs a consideration of efficient balance between the nucleation overpotential, the polarization voltage, and Coulombic efficiency. This insight underscores the pivotal role of well-suited pore structures in three-dimensional hosts, providing profound guidance for the efficient design of advanced host for lithium metal anode.

Izazivanje latentnih tragova papilarnih linija metodom elektrohemijske depozicije nikla na mesingu

Introduction/purpose of the research: Latent fingermarks can be found on the crime scene on various surfaces and made visible by different forensic methods. As this evidence can often be found on brass surfaces (ammunition casings, decorative items, etc.) the paper discusses the possibilities of applying electrochemical deposition of nickel on brass. The condition for the application of this technique is the existence of a conductive substrate. Fatty components of latent fingermarks have insulating properties and prevent the electrodeposition process. Methods: Experimental thin rectangular pieces of brass foil were used as substrates for latent fingermarks. Samples were degreased in acetone and ethyl alcohol, rinsed in deionized water, and dried in a stream of compressed air before leaving the fingermarks. To enhance the presence of sweat on friction ridges, the hand was placed in the silicone glove for five minutes. A slight touch of the index finger was left on the tiles. Fingermarks were developed on brass samples by fingerprint powder and the electrochemical deposition of nickel on another brass surface simultaneously. In order to obtain the best possible evidence, the parameters affecting the deposition rate (current density, deposition time) were changed until a clear fingermark was obtained. Results: The fingermarks were compared visually using a magnifying glass with illumination to observe the contrast between the papillary lines and the interpapillary space and the characteristic details (minutiae). The optimal results were achieved with the current density (deposition rate) of 50mA/cm2 for 10s. Conclusion: Electrochemical deposition of nickel on brass is an applicable technique for developing latent fingermarks with certain limitations.

In Situ Reaction Fabrication of a Mixed‐Ion/Electron‐Conducting Skeleton Toward Stable Lithium Metal Anodes

Lithium metal batteries are emerging as a strong candidate in the future energy storage market due to its extremely high energy density. However, the uncontrollable lithium dendrites and volume change of lithium metal anodes severely hinder its application. In this work, the porous Cu skeleton modified with Cu6Sn5 layer is prepared via dealloying brass foil following a facile electroless process. The porous Cu skeleton with large specific surface area and high electronic conductivity effectively reduces the local current density. The Cu6Sn5 can react with lithium during the discharge process to form lithiophilic Li7Sn2 in situ to promote Li‐ions transport and reduce the nucleation energy barrier of lithium to guide the uniform lithium deposition. Therefore, more than 300 cycles at 1 mA cm−2 are achieved in the half‐cell with an average Coulombic efficiency of 97.5%. The symmetric cell shows a superior cycle life of more than 1000 h at 1 mA cm−2 with a small average hysteresis voltage of 16 mV. When coupled with LiFePO4 cathode, the full cell also maintains excellent cycling and rate performance.

Intrinsic Zinc in Brass Enables Lithium Anode Dendrite‐Free

AbstractBrass foil, composed of copper (Cu) and zinc (Zn), is a commercialized low‐cost Cu‐based matrix with lithiophilic properties. However, brass has never been employed as a current collector of lithium (Li) metal anode to suppress formation of Li dendrite. Here, we show that brass foil is directly utilized as a current collector for Li metal anodes. It exhibits a stable repeated Li plating and stripping for more than 400 h (200 cycles) with a low overpotential (∼0.018 V) and a capacity of 1 mAh cm−2 at a current density of 1 mA cm−2 in a symmetric cell, as well as a higher average Coulombic efficiency of 97.2 % for more than 120 cycles with a capacity of 1 mAh cm−2 at a current density of 0.5 mA cm−2. Thanks to the lithiophilicity of homogeneous Zn in brass, the nucleation overpotential of Li is effectively reduced and Li is uniformly deposited on the current collector without dendrite formation. Our investigation might inspire the ancient brass to apply to lithium‐ion battery.

Enhanced piezoelectric performance of ceramic-polymer composite cantilevers with thin metal substrates

In this work, the electromechanical properties of a lead zirconate titanate-poly(vinylidenefluoride-trifluoroethylene) ceramic-polymer composite on thin brass and steel substrates were investigated. Samples were stencil printed on metal foils and cured at 120 °C. The effective transverse piezoelectric coefficient (d31eff) was calculated by utilizing the converse piezoelectric effect and measuring the displacement of a cantilever sample’s tip in an electric field. Interestingly, the results showed improved piezoelectric properties with the stiffer steel substrate samples. The highest d31eff achieved was about −22 pm/V, which was 29% higher than in samples printed on brass foil (−17 pm/V). Both are substantially higher compared to the coefficients reported with similar ceramic-polymer composites on polymer substrates. The improvement is suggested to originate from the prevention of buckling effects and more effective bending deformation, while the structure remained flexible. Due to the high effective values of d31 and g31, the developed material and cantilever structures are feasible for both sensor and energy harvesting applications.

Mechanical and micro-structural characterization of hot rolled brass foil

To assist the large-scale production of micro parts by micro sheet metal forming processes, mechanical and microstructural behaviors of metal foils are required. In the present study, an attempt has been made to characterize these properties of 100-μm thickness as-received brass foil. Mechanical characterization of foil has been done with tensile tests, bending tests and Nakazima tests. From the tensile test analysis, it has been observed that change in strain rate has a negligible impact on flow stress. However, serrations observed in flow stress are dependent on strain rate. The Electron backscatter diffraction (EBSD) analysis of as-received and post-deformed specimens shows the concentrated rise in Kernel average misorientation, high angle grain boundaries and low angle grain boundaries in deformed specimens. The fracture morphology study shows the presence of ductile fracture in the middle region of the fracture cross-section with shear lips in the edge region. Bending experiments show that the spring-back angle increases with the increase of bending angle up to 120°. After that, with an increase in bending angle, the spring-back angle decreases. The forming limit curve (FLC) obtained from the Nakazima test was compared to FLC obtained from different prediction criteria. From this study, it was observed that the FLC obtained from Marciniak-Kuczynski (M-K) criterion showed a good prediction of FLC for brass foil. However, FLCs obtained from Swift-Hill criterion, Abspoel empirical criterion and Pamstamp's Matwizard module over estimated foil's formability.

Effect of Interlayer Composition on Microstructure and Properties of Titanium/Aluminum TLP Bond

Abstract The transient liquid phase bonding of titanium and aluminum alloys was investigated, in which the interlayer was a 30-µm-thick brass foil and pure silver foil. The optimized variables used in this work are bonding temperature and time of 600°C and 30 min, respectively. The bonding temperature of 600°C (higher than both Al–Ag and Al–Cu eutectic temperatures) was selected to ensure melting. In both cases, an interesting intergranular eutectic-like phase was observed along the Al2024 grain boundaries. The evaluation of the interfaces of joints via optical microscopy, scanning electron microscopy, line scan, and X-ray diffraction demonstrated that a high temperature in the transient liquid phase process leads to the diffusion of alloying elements to form the molten eutectic. By holding the joint at the bonding temperature, the diffusion of alloying elements resumes, and the liquid interlayer solidifies isothermally because of the changes in the composition of the melted interlayer. The formation of Al2Cu, MgZn2, and TiMg3Zn15 phases was confirmed in the specimen made with brass foil as the interlayer. The interface width is decreased significantly from 8 µm to 2 µm by using silver foil instead of Cu–Zn foil as the interlayer. It is suggested that applying silver interlayer was successful in controlling the diffusion between two base metals and resulted in the formation of Ag2Al and AgMg phases on the fracture surface. This joint gave a higher shear strength of 154.7 MPa. The significant reduction in the strength of the bond due to using Cu–Zn foil as an interlayer (70.2 MPa) can be attributed to aggregation and growth of the brittle intermetallic compounds (IMCs) in the vicinity of the joint interface.

Experimental and Numerical Investigations on the Interface Characteristics of Laser Impact-Welded Ti/Brass Joints

The dissimilar welding of metal Ti and alloy brass foils was achieved via laser impact welding. Three laser energies were used, and the interface characteristics of Ti/brass joints were systematically investigated through experiments and smoothed particle hydrodynamics (SPH) simulation. Results indicated that the Ti/brass interfaces under all three laser energies were ring-shaped, and the increase in laser energy resulted in the increase in effective welding area. The phenomena of jet, interface waveform, and cracking were observed at the interface. Jet particles were released from both the Ti flyer and brass target, and interfacial elemental diffusion occurred. SPH simulation results showed that the generation of the interface waveform was related to the collision point position and jet particle ejection direction. The size of the interface waveform increased with the laser energy and increased along the welding direction. This finding was correlated with the horizontal welding velocity, jet velocity, and normal stress. Three different interface failure modes were included in the tensile shear tests, and the maximum tensile force of Ti/brass joints increased with the laser energy.

Promotion of brass nanowires with lanthanum oxide and its application for photodegradation of tetracycline wastewater.

Today, pharmaceuticals are considered as one of the sources of water pollution, among which antibiotics have complicated structure and antibacterial property, so they cannot be removed from water by common treatment methods. Tetracycline is an antibiotic which is used to treat humans and infected animals. Photocatalytic degradation is an effective method which is used for the removal of antibiotics from water. In this work, brass foils were coated by lanthanum oxide using dipping method. The coated foils were calcined; nanowires grew, so lanthanum oxide was sintered to the brass nanowires. The prepared photocatalyst was characterized by inductively coupled plasma spectroscopy, X-ray diffraction, scanning electron microscopy, and porosimetry techniques. The photocatalytic degradation operating conditions including pH, initial concentration of tetracycline wastewater, and time were modeled and optimized by Design Expert software (version 10). The La2O3/brass photocatalyst was active under irradiation of ultraviolet, LED, and sunlight. The maximum tetracycline photodegradation yield was 89.97% obtained by La2O3/brass foil with the dimensions of 1 cm × 3 cm, 100 mL of tetracycline solution with the concentration of 5 mg/L and pH of 10 under ultraviolet irradiation for 120 min.

Effect of geometric parameters on the performance of motorcycle catalytic converters

The critical environmental issues of the Indonesian automotive market growth are the increase in air pollution. Vehicle exhaust emission can cause significant problems for the human health and the environment. Therefore, vehicle emission control is indispensable to mitigate the environmental problem. One of the most widely used methods to reduce automotive emission is utilization of catalytic converter in exhaust system. In fact, the catalyst performance in the reduction of noxious gases depends on its material and geometric design. This study aims to evaluate the effect of geometric parameter on the performance of motorcycle catalytic converters. In this experimental study, the catalytic converter made of brass foil plate is mounted on motorcycle muffler. The effectiveness of three catalyst geometry models namely flat perforated plate, folded perforated plate and rolled brass sheet, will be evaluated in relation to the reduction of hydrocarbon (HC) and carbon monoxide (CO) content. HC and CO emission levels are measured by four gas analyzers. The results show that the geometric parameter has a significant effect on HC and CO’s composition in the exhaust gas. For idle speed test, the second geometry model of catalyst presents the best performance in reduction of Hydrocarbon and CO2 concentration.

Micro-forming analysis of ultra-thin brass foil

ABSTRACTForming process in sheet metal working refers to the manufacturing of products by deforming the material in the required die cavity without being broken or local necking. Defects such as wrinkling, local necking, and cracking may occur during the process. These are the results of either reduction or increase in sheet thickness while the material is being stretched inside die cavity. Prevention of defects is important during forming and is challenging if the thicknesses of forming sheets is less than 100 microns. These sheets are applied in the manufacturing of components having two dimensions of less than millimeter size, an operation known as micro-forming. Miniaturization has attracted many fields such as medical instrumentation, mobile manufacturing, automotive, and aerospace. Appropriate strain distribution in forming ensures products with better quality. Forming limit diagram (FLD) has been invented to plot major and minor strains along with forming limit curves. In other words, FLD shows wrinkling, localized necking as well as safe zones with various strain paths, and it proves to be a basic tool for understanding rupture characteristics of the material. There are three approaches for plotting FLD such as empirical (analytical), numerical, and experimental. The research work presents experimental micro-forming investigations on an ultra-thin brass sheet of 90 microns, to plot FLD, using the limit dome height test according to ASTM E2218-02 standard. The experimental setup was designed and developed to micro-form standard specimens applying 15 mm hemispherical punch. FLD plotted with experimental and empirical approaches shows agreement on failure limit curve.

Evaluation of dynamic development of grain structure during friction stir welding of pure copper using a quasi in situ method

By employing a quasi in situ method, we investigated the dynamic evolution of the grain structure considering the material flow, strain, and strain rate in the friction stir welding of pure copper. The tool ‘stop action’ and rapid cooling were employed and a brass foil was used as a marker to show the material flow path. The grain structure along the material flow path was characterised using electron backscatter diffraction. Static recrystallization occurs for the work-hardened base material in the preheating stage in front of the tool. In the acceleration flow stage, grains are significantly refined by plastic deformation, discontinuous dynamic recrystallization, annealing twinning during the strain-induced boundary migration and slight continuous dynamic recrystallization. In the deceleration flow stage, due to a strain reversal, the grain first coarsens, and is thereafter refined again. Finally, the hot-deformed material in the shoulder-affected zone is ‘frozen’ directly whereas that in the probe-affected zone undergoes significant annealing; thus, the recrystallized microstructure and 45°-rotated cube texture are obtained in the probe-affected zone.

Effect of crystallographic texture on the forming limit in microforming of brass

Microforming is an emerging technology to manufacture products in the light of miniaturization in several domains of industry. Plastic anisotropy is one of the material characteristics significantly affecting the micro forming process. The crystal orientation influences tensile strength, yield strength and ductility, depending on different grain sizes and principle sliding planes. The present work elaborates on the influence of the plastic anisotropic in microforming for a plane stress state condition. Yield function and constitutive equations for the anisotropic material with consideration of the crystal lattice constants and parameters of crystallography texture are proposed. The crystal orientation is considered in a subroutine VUMAT algorithm, as an internal variable based on the developed mathematical model which is implemented in Abaqus as an user material subroutine. Micro limiting dome height experimental tests for different strain paths are conducted with brass foils. The results are compared with that predicted with numerical analysis, considering critical damage and element deletions. The numerical and experimental results show a good agreement for the Alpha brass ultra-thin foils, using a set of failure criterion.

A novel approach for producing in situ Al-Al2Cu composite via friction stir processing

In situ Al-Al2Cu surface composites were synthesized via friction stir processing (FSP) at aluminium plate with brass foil interlayer(s). The effects of rotational speed, number of FSP passes, and number of brass interlayers were investigated. Defect-free surface composites with the Al2Cu particles were successfully produced in all the processed FSP conditions. The surface composites consisted of a fine grained aluminium matrix (2–10 μm), Al2Cu particles and some unreacted brass fragments remain mainly at the bottom of the stir zone. An improvement in hardness (up to 300%) compared with the aluminum base metal was achieved. Also, the activation energy and diffusion pre-factor of Al2Cu phase produced by FSP were estimated.

In-situ grown nanoporous Zn-Cu catalysts on brass foils for enhanced electrochemical reduction of carbon dioxide

In-situ grown nanoporous Zn-Cu catalysts were prepared by simply annealing a commercial brass foil at 500 °C in air, followed by electrochemical reduction. During the annealing process, Zn preferentially melted and migrated out of the framework of the alloy to form a thin layer of ZnO on its surface. Subsequent electroreduction created nanoporous Zn-enriched surface. The Zn concentration increased from 36% to 50% by 10 min, to 81% by 3 h, and to 87% by 12 h annealing treatment while the average pore size decreased from 290 nm to 120 nm as the annealing time increased from 1 h to 12 h. Faradaic efficiency of CO2 reduction to CO and HCOOH was enhanced by nearly 4 and 6 times, respectively, as compared to untreated brass foils. The nanoporous Zn-Cu catalyst presented a stable ratio of CO/H2 and a steady working current density in a continuous electrolysis of 18 h in 0.5 M KHCO3 solution.

Vacuum distillation derived 3D porous current collector for stable lithium–metal batteries

Lithium metal has been considered as the most ideal anode in lithium based batteries due to its high specific theoretical capacity and lowest working potential. Nevertheless, the growth of dendritic or mossy Li, the crush of solid electrolyte interface (SEI) layer and the successive reactions between the fresh Li metal and electrolytes hinder the commercialization of Li metal anode. In this paper, we utilize an environmental–friendly and low–cost one–step facile vacuum distillation approach to fabricate the 3D porous Cu current collector from commercial brass foil (Cu–Zn alloy) for Li metal anodes. The continuous porous 3D Cu skeleton is obtained after the vacuum distillated the low boiling point Zn (907 °C) component. The voids of the 3D porous copper can be easily regulated by adjusting the distillation temperature and time. As a current collector, the as–prepared 3D porous copper can inhibit the growth of Li dendrite and mitigate the huge volume change of Li metal anode during cycling process, resulting in stable SEI layer and electrode structure. As a result, the 3D porous Cu current collector can achieve a steady Coulumbic efficiency after 120 cycles at 0.52 mA cm−2 and for more than 80 cycles at 1.04 mA cm−2 with much reduced polarization. A long lifespan of 800 h is attained in the symmetric Li|Li@Cu battery, and it also indicates the potential for practical application when the Li@Cu|Li(NiCoMn)O2 full battery is built. More promisingly, such a vacuum distillation method is plain and simple to be combined with current commercial technique of Li metal anode manufacture using a Cu current collector, exhibiting great potentials to accelerate the commercialization lithium metal based (such as Lithium–sulfur and Lithium–air) batteries and the development of high–energy lithium–ion batteries.