Surface Of Copper Plate Research Articles

Electrodeposition transition layer induced Cu/PPr hybrids

The high-performance metal-plastic hybrids have been widely applied in lightweight manufacturing. In this work, microstructures were prepared on the copper plate (Cu) surface using an electrodeposition process. Afterward, this microstructure was used to join with the pentatricopeptide repeats (PPr) to obtain Cu/PPr hybrids. The effect of electrodeposition process parameters on surface morphology was explored. The polyacrylic acid (PAA) content had the most significant effect on the surface morphology, and an increase in PAA content resulted in a shift from a lamellar to a granular structure. When the PAA content was 5 g/L, electrodeposition time was 300 s and the current density was 25 mA/cm2, the transition layer on the Cu surface was optimized, the roughness reached 164 nm, and the contact angle decreased to 2.41°. Meanwhile, the effect of molding temperature on the strength of the hybrids was explored, and the joining strength of the hybrids reached a maximum of 13.45 MPa when the temperature was 270 °C, which is 73.5 % of the strength of the PPr matrix. Further elevation of the molding temperature failed in the transition layer due to oxidation. The joining strength of the hybrids relies solely on the mechanical interlocking ability of the interface. The Cu/PPr hybrids provide design ideas for the practical production of copper-plastic composite pipes.

Experimental studies of hydrodynamics of the «plate» type canonical region with a modified surface

The possibility of using biomimetic approaches, in particular, the "lotus leaf" effect, expressed in the superhydrophobicity of streamlined surfaces, is considered. The results are presented of experimental studies of the influence produced by various modifications of the surface of the “plate” type canonical region on its hydraulic characteristics. The plates were streamlined in a hydrodynamic tray of rectangular cross-section. Copper plates with dimensions of 200x300x1 mm were studied. Three plates were considered, identical in geometry, but with different surface conditions — one in its original state; one with surfaces modified based on a surfactant; and one with surfaces treated by laser ablation (laser formation of a multimodal relief) with subsequent modification based on surfactants. In the course of experimental studies, the velocity distribution behind streamlined plates with different surface characteristics was obtained. Based on the nature of the velocity variations of the trail behind the streamlined plates, it is concluded that the amount of hydraulic resistance decreases due to surface modification. The weighted average velocity behind the streamlined plate increased by more than 4% for a plate with a combined modified surface compared to the original one. The process of a copper plate surface modifying using laser ablation, as well as the formation of additional surfactant molecular layers in order to achieve the maximum effect of superhydrophobicity is described. The most effective technological features of the laser ablation process are determined, such as the radiation power and frequency, the most preferred relief of modified surfaces and its geometric parameters. The most characteristic features of the influence of the surface roughness on the wetting angle (θ) are considered. With the OSA 20 complex, the wetting angles were determined for all the prepared plate samples. The research results prove the prospects of this surface modification technology for use in hydraulic machines.

Claude Chamber

Proto-photographic and proto-cinematic technologies are an unending source of inspiration for a visual artist. We want to consider the case of an eighteenth-century optical device, the Claude mirror, as a starting point for an artistic collaboration.
 The Claude mirror is a small black convex mirror named after the painter Claude Lorrain and used by late eighteenth-century and early nineteenth-century painters and travellers for viewing landscapes. The dark mirror surface produces an image with a limited tonal range, allowing the viewer to look at the environment as if it were a painting. A famous Thomas Gainsborough drawing shows a man seated on a bank with a sketchbook on his lap and holding an oval mirror propped against a tree branch (Gainsborough, 1750-55).
 In spring 2019, in a flash of joint inspiration, we conceived a method of combining aspects of our artistic processes: Salla’s moving image and Laura’s printmaking practice. For 18 months, we captured photographic time-lapse sequences of everyday views from the backyards of our studios, residencies, and homes as reflections on the surface of copper plates installed in the environment (Myllylä and Vainikka, 2021). In the resulting installation, titled Claude Chamber, we projected the video sequences on the gallery space, reflected via the same mirror surfaces, and the projected images became distorted and spatial.
 We were intrigued by this optical device, in which characteristics of photography and printmaking meet. One can think of a Claude glass as a predecessor of the camera viewfinder, an early photographic gesture. It can also be viewed as a printing plate, a matrix reflecting a view. In a traditional printing plate, the image is attached or fastens itself onto the surface of the plate; in our installation, the image is transient and moving.

Reduction of copper oxide by formic acid in a narrow gap under various conditions

In this study, the reduction rate of a copper oxide film by formic acid gas was measured under various conditions using a vacuum chamber and ellipsometer. The results revealed that the reduction rate of the oxide film in a narrow gap on the copper plate surface covered by a glass plate was 1.2 times greater than that on the surface of an uncovered copper plate. In addition, the reduction rate determined for a mixture of formic acid gas with a partial pressure of 1000 Pa and N2 gas with a partial pressure of 19 000 Pa was approximately two times lower than that measured for pure formic acid gas supplied at a pressure of 1000 Pa. Meanwhile, increasing the partial pressure of formic acid increased the copper oxide reduction rate. Finally, the reduction rates calculated using a direct simulation Monte Carlo method were in good agreement with the experimental data.

Microwave Soldering of Low-Resistance Conductive Joints-Technical and Economic Aspects.

Soldering processes are applied in the fabrication of electronic circuits used in most modern domestic and industrial technologies. This article aims to introduce a new soldering technology based on the microwave joining of copper materials used in electronic applications. The study was focused on microwave technology used as the thermal source for soldering. A simulation model of temperature distributions in copper plates with overall dimensions of 50 × 10 × 0.8 mm was developed in order to determine the necessary microwave power for soldering. For 270 °C simulated on the surface of copper plates, the microwave-injected power was determined to be 598.89 W. An experimental program for 600, 650, 700, and 750 W was set in order to achieve soldering of copper plates in less than 1 min. Soldered copper plates were subject to electrical resistance measurements being obtained with variations up to ±1.5% of the initial electrical resistance of the base materials. The quality of joints has also been analyzed through microscopy after the soldering process. In addition, mechanical properties were determined using a universal testing machine. The results have shown similar behavior of the samples layered with SAC on the one-side and double-side but also a significantly lower force before breaking for one-side-layered samples. An economic analysis was performed and the results obtained have shown that in terms of energy efficiency and total costs for microwave soldering compared with manual soldering, microwave soldering is cost-effective for industrial processing.

Synthesis of a siloxane oligomer containing methyl acryloxy group for promoting the adhesion of addition-type silicone rubber to copper plate

An adhesion promoter containing methyl acryloxy group was synthesized according to a non-hydrolysis sol-gel method with methyl phenyl silicone oil containing hydroxyl terminal group, methyl vinyl dimethoxy silane, and γ–methyl acryloxy propyl methyl dimethoxy silane (KH572) as raw materials and then applied in an addition-type silicone rubber. The structure of the product was characterized by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance hydrogen spectrum (1H NMR). In addition, scanning electron microscope (SEM), mechanical testing machine and video-based optical contact angle measuring instrument were used to test its performance. We found that the adhesion promoter largely improved the bonding performance of the addition-type silicone rubber and showed the better compatibility with liquid silicone resins. When the amount of the adhesion promoter was 2.0 phr, the shear strength between silicone rubber and copper plate reached 1.33 MPa. The optical performance test results indicated that the light transmittance of silicone rubber was slightly changed when the addition amount of the adhesion promoter was no more than 2.0 phr, and this met the encapsulation requirements of electronic packaging adhesives. The contact angle test results indicated that the adhesion promoter reduced the static contact angle between the liquid silicone rubber and copper plate surface and improved the wettability. In addition, oxidation experiments, thermal resistance experiments, SEM tests and XPS surface analysis preliminarily proved that the adhesion promoter could significantly enhance the adhesion via chemical bonds formed with both the cured silicone rubber and the surface of copper plate substrate.

Research on Anti-Icing Performance of Graphene Photothermal Superhydrophobic Surface for Wind Turbine Blades

In this study, graphene is used as a photothermal material, which is added to the SiO2 superhydrophobic solution treated with fluorine silane, and then sprayed on the copper plate surface to prepare a new type of photothermal superhydrophobic surface with contact angles up to 160.5° and 159.8°. Under the conditions of natural convection, the effects of photothermal superhydrophobic surfaces on droplet condensation, freezing, and frost growth are investigated in different environments. The results show that the photothermal superhydrophobic surface can not only delay the freezing of surface droplets, prolong the freezing time of droplets, and reduce the thickness of the frost layer, but also allow for the rapid removal of droplets under near-infrared (NIR) irradiation. If the droplet is irradiated by an infrared laser emitter while the cooling system is still turned on, the internal temperature of the droplet will always be higher than the crystallization temperature under the illumination intensity of 2 W/cm2, and the droplets will not freeze. With the extension of irradiation time, the droplet will evaporate, and the volume of the droplet will decrease. On the basis of summarizing and evaluating the study on the anti-icing performance of superhydrophobic surfaces and the properties of photothermal materials, a new research direction regarding the anti-icing of fan blade surfaces was established. This kind of surface combines the photothermal capabilities of light absorption materials with the micro- and nanostructure of the superhydrophobic surface to improve the anti-icing capability of wind turbine blade surfaces in difficult conditions.

Online optical inspection of electrolytic copper plate based on digital moiré

The application of automatic inspection plays an important role in improving the quality of industrial products. Aiming at nodules on the surface of electrolytic copper plate, this article introduces a comprehensive optical online inspection method. In order to obtain dynamic information of product and overcome the interference of random factors such as large-curvature deformation, position deviation and tilt, the system integrates a variety of single technologies including digital moiré, image recognition and spatial transformation. The online test results show that the system can effectively extract the information of nodules and automatically classify the products according to the set threshold.

Potential formation on floating metal plate treated by low-temperature atmospheric pressure plasma jet

In the biomedical applications using low-temperature atmospheric pressure plasmas, charging on surface of the targets could play an important role. In this study, we have investigated potential formed on an electrically floating copper plate treated by a low-temperature atmospheric pressure helium plasma jet. The potential of the copper plate was measured by an electrostatic sensor in a non-contact manner. It was found that the potential on the copper plate could be controlled from 200 to −600 V by changing the distance between the nozzle of plasma device and the surface of copper plate. We discussed the charging mechanism such as collection of charged particles and several processes of electron emission including thermionic, field emission, secondary electron emission, and photoelectric processes.

Investigating the nodulation mechanism of copper cathode based on microscopic approach: As a punch failure factor

The presence of nodules on the surface of cathode copper plates was the most important reason for the failure of the punch of mechanical clinching of copper cathode sheets. This study demonstrated a comprehensive investigation into the nodulation growth of copper cathodes in the electrorefining plant based on metallographic analysis. More than 15 random samples were selected from the top, middle, and bottom of the cathodes produced in the Khatoon Abad copper refinery, Iran. Studies were carried out based on the determination of growth modes including field oriented isolated crystal (FT), basis-oriented reproduction (BR), field-oriented texture (FT), and unoriented dispersion (UD). A scanning electron microscope equipped with the EDS spectrometer was used to determine the elemental analysis of the origin of each nodule and investigate the effect of entrapped slimes impurities on the nodules' microstructure. The results confirmed that the physical and chemical adsorption of inhibitors including Fe, Ni and Mn as hydrated phases on the preferred active sites restricted the FT growth mode at the first stages of crystallization. Then, it enhanced the local current density and cathodic polarization promoting the UD growth mode. The same mechanisms occurred when as-received-casted anodes replaced the cathode and caused the formation of cavity at the preferred active site and intense nodulation at the border of the sample. Analysis of this site of nodules’ root revealed that the aggregation of inhibitors at the lower preferred active sites, i.e., lower than 5 mm, provided the possibility of large local current density, polarization and encourage the formation of brittle deposition as MeOH. In this case, the formation of the spongy nodule was dominant.

Toward Easily Enlarged Superhydrophobic Copper Surfaces with Enhanced Corrosion Resistance, Excellent Self-Cleaning and Anti-Icing Performance by a Facile Method.

This work reports a facile method for fabricating superhydrophobic surface on copper plate by AgNO₃ treatment and dodecyl mercaptan modification. The as-prepared superhydrophobic copper plate presents hierarchical and rough morphology composed of nanosheets and nanoparticleformed matrix. Meanwhile, long alkyl chains are assembled onto the rough surface successfully. Consequently, the copper plate is endowed with excellent superhydrophobic performance with a water contact angle of 156.8° and a rolling angle of ca. 3°. Moreover, the superhydrophobicity has long-term durability and excellent stability. Grounded on the strong water repellence, the resultant superhydrophobic copper plate surface exhibits multi-functions. The excellent performance can be well explained by "Cushion effect" and Capillary phenomena. As a result, water and corrosive species can be prevented from contacting with the copper plate surface, and contaminants can be taken away easily by the rolling water droplets. Meanwhile, the icing process of water is delayed on the superhydrophobic surface. Therefore, the superhydrophobic copper is endued with enhanced corrosion resistance, excellent self-cleaning and anti-icing performance. We believe that this facile method provides a simple and cost-effective process to improve the properties of copper plate, and which may see practical application of the superhydrophobic materials.

Starfish surface-inspired graphene-copper metaparticles for ultrahigh vertical thermal conductivity of carbon fiber composite

Carbon fiber reinforced composites (CFRCs) have received increasing interest for their unique feature of excellent strength-to-weight ratio and their applicability in various fields from aerospace and automobile to electronics. Here, we report an unprecedented effective fabrication strategy to construct an extremely thermally conductive, mechanically robust, and highly durable CFRC on the basis of creation of vertical heat dissipation network using the starfish surface-inspired graphene-copper metaparticles. A new type of thermally conductive composite with a very low content of metaparticles is achieved by the simple spray coating and subsequent high-temperature compression of multi-scaled graphene and copper particles. It is experimentally demonstrated that the vertical thermal diffusion of peculiar metaparticles with starfish surface-like structure, in which multiple bundles of graphenes exist as protrusions on the surface of copper plate, affords a vertical heat dissipation network via interlayer contact between large-sized copper components of metaparticles. As a consequence, this simple approach provides ultrahigh vertical thermal conductivity and excellent mechanical strength, as well as a high heat durability for the composite. An unprecedented vertical thermal conductivity with 520% enhancement, which is the highest vertical heat transfer performance achieved so far, and remarkable vertical thermal diffusivity with 643% improvement are accomplished by our method.

Investigation on the roll-to-plate microforming of riblet features with the consideration of grain size effect

Large-area micro surficial features can realize different functions such as reducing the flow friction and improving the hydrophobicity. However, an evident challenge is how to realize the fabrication of thousands of micro features on large area in an efficient and low-cost manner. Roller microforming process is a satisfying method in that regard. Since the dimensions of micro features are in the same level with the grain size, the so-called size effect occurs during the microforming process. To understand how the size effect influences the roll-to-plate (R2P) micro imprinting process, experimental setup was established to form micro riblet features onto the surface of copper plate. The imprinted feature height is revealed to increase with the grain size. The flow stress reduction with the increase of grain size was identified to be the major reason for the increase of forming height at the smaller grain size condition. However, an evident underestimation was revealed for the case with the grain size of 180 μm. A further study was conducted by considering the crystalline microstructures via the Voronoi algorithm. The predicted forming heights were found to agree with the experiments, suggesting the inhomogeneous deformation of individual grains could improve the formability of material in the R2P microimprinting process. The uneven nature of individual grains actually lowers the difficulty of material flow since the deformation is easier to initialize and localize at weaker grains during imprinting.

Cathodic copper plate surface defect detection based on bird swarm algorithm with chaotic theory

Cathodic copper plate surface defect detection based on bird swarm algorithm with chaotic theory

Superhydrophobic copper surface fabricated by one-step immersing method in fatty acid salt aqueous solution for excellent anti-corrosion and oil/water separation properties

One-step immersing method is proposed to fabricate superhydrophobic coating on the surface of copper plate and copper mesh in sodium laurate or sodium decanoate aqueous solution. The appropriate concentration range of fatty acid sodium salts and the immersing time are investigated systematically, exhibiting a short immersing time (3 h) to form superhydrophobic surfaces. The sheet structures on the superhydrophobic surfaces are confirmed by scanning electron microscope and X-ray diffraction measurements. The formation mechanism is analyzed according to the X-ray photoelectron spectroscope and Fourier transform infrared reflectance spectra measurements. Electrochemical impedance spectroscopy measurements indicate the excellent anti-corrosion property with corrosion inhibition efficiency of 99.14% in Yellow Sea water. The superhydrophobic copper mesh is proved to be applicable for a variety of oil/water separation, including oils in lab and in daily life. The superhydrophobic copper surface fabricated in this paper will have potential applications in the protection of metal corrosion and the removal of oil contamination.

Arc discharge and pressure characteristics in pulsed plasma gas of PAW

This paper investigated the arc characteristics in pulsed plasma gas of plasma arc welding using a synchronous image- and electrical signal-acquisition system. The arc sizes (including the arc length L, the arc width on the water-cooling copper plate surface Wa, and the arc width under the nozzle Wc) and arc voltage changed regularly with the plasma gas periodically on/off. And the changing trends of arc sizes were affected by the plasma gas flow rate and the plasma gas switching frequency. The changing scale of arc voltage was proportional to the plasma gas flow rate and was inversely proportional to the plasma gas switching frequency. The average plasma arc welding (PAW) and plasma arc welding with pulsed plasma gas (PPG-PAW) arc voltages were equal when the plasma gas flow rate was the same. The arc pressure also presented cyclical changes during the plasma gas on/off, and the changing scale and the axial mean value were inversely proportional to the plasma gas switching frequency. The periodically oscillating arc and arc pressure would be beneficial to the refinement of grain structure during the welding process.

ВПЛИВ ОБРОБКИ ПОВЕРХНІ ЗА ТЕХНОЛОГІЄЮ SMAT НА МЕХАНІЧНІ ВЛАСТИВОСТІ ПОВЕРХНЕВИХ ШАРІВ МІДІ

Nanostructured materials are characterized by a specific structure compared to polycrystalline materials. Nanostructured materials are created in way of strong deformations. SMAT (surface mechanical attrition treatment) technology consists in the treatment of the surface of a material with steel balls accelerated by a generator of high-frequency oscillations (about 20 kHz). This changes the mechanical properties of the materials. The size of graines in such materials decreases in the direction from the volume of the crystal to the surface. As a result of SMAT processing, graines become nanosized near the surface of the samples. Such materials have a large number of subsurface defects formed as a result of intense plastic deformation, which determines their thermodynamic and diffusion characteristics. The purpose of this work is to develop the device of high-frequency (20 kHz) surface machining by attrition using SMAT technology and its application to the treatment of surfaces, both polished copper plates and electrodeposited in a stationary mode to copper plates with copper layers. In this work, the device is developed and the technology of high-frequency mechanical surface treatment of SMAT is described. The design features and technical characteristics of the experimental plant are presented. In the work, the surfaces of copper substrates were processed by different methods: grinding and polishing of copper polycrystalline plates, electrolytic deposition of copper surface layers on these plates, processing of prototypes by SMAT technology. The microhardness was measured in the surface layers of the linings made using different technologies and their comparative characteristics were performed. It is established that high-frequency surface treatment of plates by SMAT technology increases the microhardness of the surface of copper plates of different types, both polished and with electrolytically deposited copper. The results of the research showed that the sample, which was subjected to electrolytic deposition of copper, has a high defectiveness of the surface and reduced microhardness. After processing such a sample using SMAT technology, it is obtained a hardness higher than the reference polycrystalline copper sample.

Heat transfer characteristics of free nanofluid impinging jet on flat surface with different jet to plate distance: An experimental investigation

In the present study, the heat transfer characteristics of the impinging jet on the heated copper plate surface was investigated experimentally. Two different working coolants namely, DI water and aqueous Zinc oxide (ZnO) nanofluids with varying nanoparticle concentration (ϕ = 0.02%, 0.04%, 0.06%, and 0.1%) were used during the experiment. The ZnO nanofluids were synthesized by two-step methods. The experiments were conducted by impinging free circular jet fluids (water and ZnO nanofluids) on a 90 mm diameter and 3 mm thick heated copper plate. The jet parameters viz. nozzle to plate distance (2–7.5), the flow rate of fluids and nanoparticle concentrations were varied during experiments. This analysis reveals that there is a significant enhancement in heat transfer coefficient (HTC) for ZnO nanofluids coolant when compared with water coolant. During experiments, Reynolds number was varied in the range from 2192 to 9241. A theoretical correlation was developed after analyzing experimental data. The experimental results were found to be in good agreement with results obtained from theoretical correlation.

Pulsed micro-discharge ambient ionization mass spectrometry

A method named pulsed micro-discharge ambient ionization mass spectrometry (PMD-AIMS) was developed for direct surface analysis with simple apparatus. In PMD-AIMS, micro-discharges is generated between a copper plate and a tungsten needle with pulsed high voltage applied, in which the analyte on the surface of copper plate is desorbed and ionized, then drawn to the inlet of the mass spectrometer. In this experiment, the tungsten needle was fabricated via an electrochemical method with sharp apex to reduce the volume of the discharge. The experimental parameters were optimized to achieve a high sensitivity and high spatial resolution for mass spectrometry imaging. LOD (S/N = 3) was determined to be 20 ng/ml for atrazine on the yam and 1 ng/ml for atrazine on the copper plate with a lateral resolution of 60 μm. The PMD-AIMS technique was further applied for the rapid detection of the residual herbicide on epidermis. The distribution of the herbicide in plant tissue was investigated with mass spectrometry imaging. The results indicate that PMD-AIMS is a sensitive analytical technique with the capability of mass spectrometry imaging.

Anodic-like Wafer Bonding of Copper/Silicon Done at Room Temperature by Schottky Barrier Structure

Metal, e.g. copper or aluminum, is difficult to be firmly bonded with silicon if only thermally treated at room temperature, because the surface status of the silicon substrate is usually in covalent bonds. However, the low temerature Cu/Si bonding structure is usually achieved by pre-depositing Cu layer on the surfaces of the silicon at relative high temperature prior to bonding. In practice, this bonding is one type of copper-to-copper bonding. In this kind of bonding case, annealing temperature is normally at several hundred °C as well. Another way is to employ a so-called “low temperature” (400°C or below) thermo-compression bonding technique to create the Si/Cu structure. The first step is to deposit a Cu layer on the surface of blanket silicon wafer. Then, in practice, the two Cu surfaces were joined together with mechanical pressing and heating simultaneously for tens of minutes. In the study, we demonstrated the copper-silicon bonding pair formed via an electrochemical processing at room temperature. The silicon substrates were double-side polished, phosphorus- doped, N-type (100) silicon wafer with resistivity of 1−10 Ω cm. The surface of copper plate was also polished. Prior to electrochemical processing, all the silicon specimens were cleaned at 80 °C in the following solutions: NH4OH:H2O2:H2O = 1:1:5 and HCl:H2O2:H2O = 1:1:6. Then silicon specimens were dipped in 0.5% HF solution for 30 seconds to remove all native oxide layer. Via a hydrophobic wafer bonding processing with HF dipping, the silicon specimen was bonded with the polished copper plate which is also as an anode electrode. The electrochemical anodization was performed in darkroom at a constant current density of 50 mA/cm2 with a platinum cathode in the electrolyte. After the electrochemical processing, we found copper was teared off and then firmly attached on the silicon surface when we tried to separate the bonded pair. We proposed that the carrier-mediated rectification through the Schottky junction of metal-semiconductor contact allows electrons drain to the copper electrode, thereby greatly increasing the hole density at the interface on the side of silicon substrate, i.e. activating the silicon dangling bonds. Once the electrons drained off to the copper electrode from silicon surface, the bonds formed on the Cu surface were also greatly activated to be bonded to silicon bonds. This kind of bonding technique of copper/silicon or metal/ceramic materials may be applied to the additive manufacturing for 3-D microstructure. Figure 1: The copper layer was directly teared from bulk copper and then transferred onto silicon after electrochemical processing at room temperature for two hours. It appears the bonding strength between copper and silicon is stronger than the bond strength of copper. Figure 1