Aluminum Copper Research Articles

Unsteady hybrid nanofluid (Cu-UO2/blood) with chemical reaction and non-linear thermal radiation through convective boundaries: An application to bio-medicine

This study is focused on modeling and simulations of hybrid nanofluid flow. Uranium dioxide UO2 nanoparticles are hybrid with copper Cu, copper oxide CuO and aluminum oxide Al2O3 while considering blood as a base fluid. The blood flow is initially modeled considering magnetic effect, non-linear thermal radiation and chemical reactions along with convective boundaries. Then for finding solution of the obtained highly nonlinear coupled system we propose a methodology in which q-homotopy analysis method is hybrid with Galerkin and least square Optimizers. Residual errors are also computed in this study to confirm the validity of results. Analysis reveals that rate of heat transfer in arteries increases up to 13.52 Percent with an increase in volume fraction of Cu while keeping volume fraction of UO2 fixed to 1% in a base fluid (blood). This observation is in excellent agreement with experimental result. Furthermore, comparative graphical study of Cu,CuO and Al2O3 for increasing volume fraction is also performed keeping UO2 volume fraction fixed. Investigation indicates that Cu has the highest rate of heat transfer in blood when compared with CuO and Al2O3. It is also observed that thermal radiation increases the heat transfer rate in the current study. Furthermore, chemical reaction decreases rate of mass transfer in hybrid blood nanoflow. This study will help medical practitioners to minimize the adverse effects of UO2 by introducing hybrid nano particles in blood based fluids.

Aluminum copper bimetallic metal organic gels/sodium alginate beads for efficient adsorption of ciprofloxacin and methylene blue: Adsorption isotherm, kinetic and mechanism studies

In this research, a new aluminum-copper bimetallic organic gel was prepared by solvothermal method. It is hoped that the special structure and properties of this new material can be used to remove ciprofloxacin (CIP) and methylene blue (MB) from water to deal with environmental pollution problems. Their morphology and structure were characterized by XRD, FT-IR, XPS, SEM, BET, TGA and zeta potential. It is proved that they have sufficient active sites, large specific surface area (270.5 m2/g), hierarchical porous structure, and strong thermal stability. These properties contribute to their efficient removal of pollutants. Compared with other adsorbents, MOG-4 in this study showed good pollutant removal rate, wide pH adaptability, good anti-interference ability and excellent reuse rate. The maximum adsorption capacity of MOG-4 for CIP and MB was 458.72 mg/ g and 381.68 mg/ g respectively. The adsorption process followed the second-order kinetic model and Freundlich isotherm. More importantly, we constructed MOG-4 @SA beads by immobilizing MOG-4 in sodium alginate (SA) matrix, which not only overcame the shortcomings of difficult recovery and easy agglomeration of powder MOG-4, but also enhanced its adsorption capacity. Seven cycles show that the reuse rate of MOG-4 @SA is more than 84%. The adsorption mechanism involves hydrogen bonding, electrostatic interaction, π-π interaction, hydrophilic/hydrophobic interaction and pore filling. MOG-4 @SA beads adsorbent overcomes the shortcomings of traditional powder adsorbent, which is easy to lose, easy to aggregate and difficult to recover, and broadens the range of use of powder adsorbent and sodium alginate. Therefore, MOG-4 @SA has the advantages of good adsorption performance, high reuse rate, wide range of adaptation, strong anti-interference ability, and is expected to become a promising adsorbent.

Adaptive convolutional neural network for aluminum surface defect detection

The aluminum surface defect detection is not trivial for the high computational cost and labor-intensive data annotation. Particularly, the characteristics of lots of very tiny objects, sample sparsity, and variations, limit the detection performance. In this paper, we demonstrate a sophisticated and efficient object detection model based on hierarchical attention and contextual information for aluminum surface defect detection. Specially, we first use a deep residual learning strategy to obtain the defect feature maps. Secondly, we add corresponding weight matrices to the defect feature maps by fusing attention mechanism and adaptive deformable convolution to achieve the fine feature. Thirdly, we construct a feature pyramid structure to achieve the fusion of multi-scale feature information. Finally, we use the obtained contextual feature information for class prediction and bounding box regression. The comprehensive experiments on the surface defect data set of aluminum and the surface defect data set of copper foil and aluminum foil respectively show that our method compared to state-of-the-art object detectors. Code is available at https://github.com/yunsheng-Wei/DFA-FRCNN.git.

Copper–Alumina Capsules for High-Temperature Thermal Energy Storage

High corrosivity, leakage, and oxidation of metallic phase-change materials (PCMs) have limited their applications in high-temperature thermal energy storage (TES) systems, regardless of their favorable benefits for high-temperature TES applications of over 1000 °C. To overcome these major challenges, this work presents a facile paraffin sacrificial layer approach for directly encapsulating copper (Cu) sphere PCMs with the alumina (Al2O3) shell, considering a buffer inner cavity. The cavity is formed by the decomposition of the paraffin layer through a pre-sintered process. It plays a key role in accommodating the volume expansion of the Cu core, thereby preventing the breakage of the shell and the leakage of the liquid PCM. A series of macrocapsules with different sizes (9.5–21 mm) containing the Cu core, cavity, and Al2O3 shell are successfully produced using the paraffin sacrificial layer method and deploying a two-step heat treatment. The experimental results show that the Al2O3 shell possesses a good structure, which can prevent the leakage of the Cu core. The Al2O3 shell also has strong compatibility with the Cu core without any chemical reaction between two materials. In a temperature range of 1000–1100 °C, the calculated mass and volume energy storage densities of the PCM macrocapsule with 21 mm outer diameter are found to be 222 kJ/kg and 745 J/cm3, which are 1.83 and 1.76 times, respectively, higher than those for the Al2O3 ceramic. After thermal cycle tests, the encapsulated Cu PCM shows superior shape stability, chemical stability, and thermal durability, which can be applied in long-term thermal storage systems for high-temperature TES systems.

Effects of laser oscillation on metal mixing, microstructure, and mechanical property of Aluminum–Copper welds

Laser welding of dissimilar metals is important in many industrial applications. However, as dissimilar metals get mixed during the melting process, intermetallic compounds are often formed in the welds which can significantly undermine the electrical and mechanical properties of the welds. This poses a critical challenge to the widespread utilization of this welding technique. Compared with conventional line-scan laser welding, oscillating laser welding offers additional processing parameters to control the welding process. Although some work has been reported on oscillating laser welding of dissimilar metals, a mechanistic understanding of this process was still missing. The research objective of this work was to reveal the physical mechanisms and evaluate their relative significance to the fluid flow, metal mixing, and microstructure evolution in the molten pool in oscillating laser welding of dissimilar metals. A combination of experiments and simulations was leveraged to achieve the objective. Four fluid flows have been found to determine the metal mixing in the molten pool, and their dependences on the laser oscillating parameters were discussed. In addition, the thermo-solutal conditions of the molten pool solidification were quantified as functions of the laser oscillating parameters, and the effects of the thermo-solutal conditions on the final weld microstructures were analyzed.

Influence of spinning flower structure inserts in the thermal performance of LS-2 model of parabolic trough collector with ternary hybrid nanofluid

Parabolic solar trough collector is the most widely accepted technology to use inexhaustible energy. Present research work proposed LS-2 model of parabolic trough collector with various spinning flower inserts and three particles based nanofluid as a heat-carrying medium. Main intention of this examination is to lower the temperature gradient in fluid flow and provide uniform distribution of heat flux on the receiver's outermost surface. A total of ten cases of PTC are examined in ANSYS 22 Fluent. Nine steady receivers are equipped with spinning flower inserts and one without inserts. Hybrid nanofluids with 1% vol. content are attained by blending aluminum oxide, copper oxide, and graphene oxide with water as base fluid. This evolution focuses on the consideration of spinning inserts in the receiver with a range of speed from 0 to 15 rad/s. The flow rate is from 0.016 kg/s - 0.033 kg/s respectively. Highest enhancement for thermal efficiency and heat transfer coefficient are 30.87% and 98.34% for case-9 at 15 rad/s inserts speed than receiver without inserts using nanofluid-6 at 0.033 kg/s. Under the same condition, the highest increment for the pump work requirement is 21.29% for case-9 than receiver without inserts. This means increment of pump work is insignificant than thermal performance improvements.

Synthesis and visible-light photocatalytic property of spinel CuAl2O4 for vehicle emissions.

Photodegradation of vehicle emissions is a promising approach for dealing with atmospheric pollution in road tunnels. In this research, copper aluminate nanoparticles (CuAl2O4) were prepared by the sol-gel method using copper nitrate, aluminum nitrate, and citric acid as precursor materials. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy to validate their structure, surface morphology, and optical properties, respectively. The XRD and SEM results confirm that the CuAl2O4 powder has a particle size of 20-37nm and exhibits a spinel-type structure. The upper limit of the stimulation wavelength in the UV-Vis diffuse reflectance spectrum is located at 725nm with a band gap (Eg) of about 1.50eV, which is suitable for effective visible-light degradation. Photocatalytic performance of the CuAl2O4 nanoparticles was analyzed by investigating the effects of light source, calcination temperature, and catalyst loading amount on the degradation of vehicle emissions (CO, HC, and NO). Best results were obtained under fluorescent light irradiation by CuAl2O4 nanoparticles calcined at 700°C. The optimum catalyst amount for decomposing CO, HC, and NO were determined as 0.5g, 0.5g, and 2g, respectively. Overall, the photocatalytic performance study verifies that spinel CuAl2O4 photocatalyst is a valuable material for next-generation technologies aimed at reducing harmful emissions from vehicles.

MHD Stagnation Point of Blasius Flow for Micropolar Hybrid Nanofluid toward a Vertical Surface with Stability Analysis

This study investigates the magnetohydrodynamics of a micropolar fluid consisting of a hybrid nanofluid with mixed convection effects. By using the dimensionless set of variables, the resulting equations of ordinary differential equations are solved numerically using the bvp4c solver in MATLAB. In the present work, the water-based alumina–copper hybrid nanofluid is analytically modeled with modified thermophysical properties. The study reveals that the highest critical value of opposing flow is the hybrid nanofluid (ϕ1 = ϕ2 = 2%). By comparing the hybrid nanofluid with Cu–water nanofluid (ϕ1= 0%, ϕ2= 1%) as well as water (ϕ1= 0%, ϕ2= 0%), hybrid nanoparticle volume fraction enhances the dynamic viscosity performance and surface shear stress. In addition, the augmentation of the nanoparticle volume fraction and magnetic field parameter will increase the physical quantities Rex1/2 Cf, Rex Mx, and Rex−1/2 Nux. The result from the stability inquiry discloses that the first solution is more physically stable and trustworthy. It is proven that magnetohydrodynamics could contribute to controlling the fluid flow in a system, i.e., engineering operations and the medical field. In addition, this theoretical research can be a benchmark for experimental research.

Grain Refinement of Aluminum and Aluminum Alloys by Sc and Zr

Rare earth elements and transition elements are widely used in aluminum alloys, magnesium alloys and copper alloys due to their unique microalloying effects. With regard to in-depth research on the grain refinement characteristics of rare earth elements and transition elements, the combination of grain refinement and microalloying in the master alloys has a great impact on the theories and technical research of refinement, and the broadening of the application field of master alloys. This paper first summarizes the grain refinement mechanisms and analyzes the effects of rare earth elements and transition elements on the grain refinement of aluminum and aluminum alloys, and summarizes the elements suitable for the preparation of Al-M master alloys and their refinement mechanism.

A Review of Cobalt-Based Metal Hydroxide Electrode for Applications in Supercapacitors

Supercapacitors are the cutting-edge, high performing, and emerging energy storage devices in the future of energy storage technology. It delivers high energy and produces higher specific capacitances. This research study provides insights into supercapacitor materials and their potential applications by examining different battery technologies compared with supercapacitors’ advantages and disadvantages. Transition metal hydroxides (cobalt hydroxides) have been studied to develop electrodes for supercapacitors and their use in various fields of energy and conversion devices. Cobalt-based metal oxides and hydroxides provide high-capacitance electrodes for supercapacitors. Metal hydroxides combine high electrical conductivity and excellent stability over time. The metal oxides used to prepare the electrodes for supercapacitors are cobalt-based metal oxides and hydroxides. It is stronger than most of the other oxides and has tremendous electrical conductivity. Cobalt hydroxides are also used in supercapacitors instead of other metal hydroxides, such as aluminum hydroxide, copper hydroxide, and nickel hydroxide. This study gives a complete overview of the preparation, synthesis, analysis, and characterization of cobalt hydroxide thin film electrodes by using the electrochemical deposition technique, parameters measurements, important characteristics, material properties, various applications, and future enhancement in supercapacitors.

Experimental study of thermal performance improvement in a cross‐flow heat exchanger by using copper foam

AbstractIn this study, copper foam was used as a porous medium in place of traditional aluminum fins. A comparison between the two heat exchangers—one with fins and the other with copper foam—was conducted under various conditions. The air inlet velocity ranged from 0.9 to 9.3 m/s, and the water inlet temperature ranged from 10°C to 18°C. Different water flow rates were tested. A comparison was made between the performance of copper foam and aluminum fins by calculating several parameters, including thermal resistance, heat exchanger effectiveness, Colburn factor, Nusselt number, friction factor, and area goodness factor (AG). The experimental results showed that at low air velocities, the heat transfer coefficient for both types of heat exchangers was almost equal. However, at high air velocities, the copper foam exhibited a higher heat transfer coefficient. The Colburn factor was higher for the heat exchanger with copper foam than in the conventional fins, where it was equal to 0.1959 for the copper foam and 0.1186 for the fins. On the other hand, the AG was higher in the case of fins than in the heat exchanger with copper foam.

Optimization of Ultrasonic Welding Parameters Based on Response Surface Methodology

In this paper, the optimal process parameters for ultrasonic welding of copper wire and aluminum plates are studied using the response surface method. The effect of various welding parameters on the welding effect is experimentally tested. The results are analyzed using the Box-Behnken design to establish a regression model to optimize the welding parameters. The model uses the welding height, welding energy and welding pressure as influencing factors and the welding strength and welding time as response values. The results show that optimal welding of copper wire and aluminum plate is obtained at the height of 2.2mm, energy 1300J, amplitude 85% or 95%. The response surface method used in this paper can provide a reference for the ultrasonic welding of other materials in the study of process parameters.

Scrutinization of MHD stagnation point flow in hybrid nanofluid based on the extended version of Yamada-Ota and Xue models

This article exhibits a brief comparative study of magnetohydrodynamics stagnant point flow in hybrid nanofluid based on the extended version of two models, known as the Yamada-Ota model and Xue model. The time-dependent and thermally radiative two-dimensional flow is processed with the involvement of a stretchable/shrinking permeable sheet. The suspension of two nanoparticles Aluminum Oxide Al2O3 and Copper Cu into the base fluid water is considered for the formulation of hybrid nanofluid. With the execution of the significant similarity transformation, the nonlinear dimensionless system in the form of ordinary differential equations is developed. The Yamada-Ota and Xue models have been implemented on the dimensionless setup of equations that further are numerically worked out via the bvp4c methodology. The velocity and temperature fields corresponding to the pertinent parameters are figured out and discussed for both concerned models. From this study, we have come up with the result that the heat transfer rate involving the Yamada-Ota model is prominent as contrasted with the Xue model. The larger strength of the stretching parameter boosts up the field of the velocity but develops the deterioration in the temperature distribution. Moreover, the field of the velocity diminishes with the accelerating quantities of the solid nanoparticle.

Effect of Annealing on the Mechanical Tensile Behavior of Copper–Aluminum Composites Prepared by Rotary Forging

Effect of Annealing on the Mechanical Tensile Behavior of Copper–Aluminum Composites Prepared by Rotary Forging

Computational analysis on magneto hybrid nanofluid flow with water as base fluid and nanoparticles as aluminium oxide (Al2O3) and copper (Cu) induced by a convectively heated stretching sheet in presence of surface slip

The present work explores the hybrid nanofluid flow of water conveying aluminium oxide (Al2O3) and copper (Cu) on a convectively heated stretching sheet in presence of a magnetic field. The radiative flow considered here is under slip velocity at the edge and heat transference mechanism due to thermal convection. The problem is developed mathematically in terms of partial differential equations (PDEs). The governing PDEs are transformed into a system of ODEs by using an apposite similarity transformation and then are explained numerically. Graphical illustrations for the dimensionless velocity and temperature are presented and discussed in detail from the physical point of view. The behavior of the rate of heat transmission and the skin friction number are also deliberated numerically for various flow parameters. The result shows that thermal outlines have a linear relationship with a thermal number and slip parameters but velocity outlines disclose a reverse relationship with the magnetic field. When compared to nanofluid flow, shear stress at the wall as well as heat transmission rate is changed for hybrid nanofluid flow due to the existence of high-conducting nanoparticles Al2O3 and Cu in the base fluid water.

A laminar forced convection via transport of water–copper–aluminum hybrid nanofluid through heated deep and shallow cavity with Corcione model

The article explores how fluid flows and heat transfers in both deep and shallow cavities when using a nanofluid made of water, copper, and aluminum oxide. The study applies the Corcione model to hybrid nanofluids, which considers viscosity, conductivity, and the size of the nanoparticle, temperature, and Reynolds number. The cavity is connected to a rectangular channel, with the cavity's length being half the total length of the enclosure, and the aspect ratio (cavity height divided by height of the channel) is tested from 1 to 3. The study uses the Navier–Stokes equation and energy equation in two dimensions, along with finite element-based software, COMSOL 5.6, to simulate the combination of fluid flow and heat transmission. The results show a circular distribution of temperature in the cavity, and the average temperature drops as the volume fraction of copper upsurges. However, both the Reynolds number and volume fraction of copper improve the average Nusselt number, which shows how well the fluid transfers heat, along the cavity's middle line. The percentage change in the average Nusselt number decreases as the aspect ratio increases, indicating improved conduction.

Using microfluidic technology to prepare octogen high-energy microspheres containing copper–aluminum composite particles with enhanced combustion performance

Aluminized explosives are widely used in military applications. However, the easy agglomeration of aluminum (Al) powder and its high ignition temperature greatly hinder the reaction of nano aluminum (n-Al) in the process of explosion, thus affecting the combustion and explosion of aluminum-containing explosives. In the present study, copper (Cu) coated n-Al composite particles were introduced into aluminized explosives, and Cu coated n-Al composite particles and ball-milled octogen (HMX) energetic microspheres were prepared via droplet microfluidic technology using binder. The morphology, crystal form, thermal properties, combustion, and mechanical sensitivity of the microspheres were studied using a variety of techniques. The prepared microspheres had regular spherical morphology and uniform particle size, with an even distribution of particles. Using microfluidic technology will not destroy the crystal form of each particle. The introduction of Cu promoted the thermal decomposition of HMX. The mechanical sensitivity of the prepared Cu/Al microspheres was lower than that of the microspheres only containing n-Al. The Cu/Al microsphere samples exhibited excellent and stable combustion performance, and that the addition of Cu increased the combustion speed compared to the microspheres only containing n-Al. This technology represents an inexpensive and simple way to improve on existing aluminized explosives.

The effect of pin thread on material flow and mechanical properties in friction stir welding of AA6068 and pure copper

This study investigated the effects of friction stir welding thread on the quality of dissimilar joints between AA6068 aluminum alloy and copper. The developed computational fluid dynamic (CFD) method was employed to simulate the tool's heat generation and thermo-mechanical action. The materials flow, microstructure, mechanical properties, and hardness of joints were assessed. The results indicated that the threaded pin increased heat generation during welding. The maximum temperature recorded on the aluminum side was 780 K for the cylindrical joint and 820 K for the threaded pin joint. The size of the stir zone in the threaded pin joint was bigger than the cylindrical pin. On the other hand, mechanical interlocking between AA6068 aluminum alloy and copper increased in the threaded pin joint. The material's velocity and strain rate increased by the higher stirring action of the threaded tool. Higher strain rate and materials velocity decreased microstructure size in the stir zone. The experimental result shows that the ultimate tensile strength of the cylindrical pin joint was 272 MPa, and the threaded pin joint was 345 MPa. The average microhardness of the cylindrical pin joint was near 104 H V, and for the threaded pin was 109 H V. The results show that the ultimate tensile strength and hardness of threaded pin joint increases by 25% and 5% in comparing cylindrical pin joint.

EXPERIMENTAL ANALYSIS ON ENHANCEMENT OF HEAT TRANSFER IN COMPACT HEAT EXCHANGER USING NANO PARTICLES

This study aims to experimentally investigate the enhancement of heat transfer in a compact heat exchanger (CHE) using nano particles, without considering the Reynolds number effect. In recent years, nanofluids have attracted attention as a promising alternative to traditional heat transfer fluids due to their improved thermal conductivity. The experimental setup consisted of a counter-flow CHE with a nanofluid circulating through the tubes. The nanofluid was prepared by dispersing Aluminium Oxide (Al2O3) and Copper (II) oxide (CuO) nanoparticles into distilled water. The effects of various parameters such as nanoparticle concentration and heat flux on heat transfer enhancement were investigated. Results showed that the addition of nanoparticles significantly increased the heat transfer rate compared to the base fluid. Moreover, the enhancement was found to be more significant at higher concentrations of nanoparticles and heat fluxes. The results also showed that the increase in heat transfer was due to the improved thermal conductivity of the nanofluid. Overall, the study demonstrated that the use of nanofluids in CHEs can significantly improve their performance, making them more efficient and compact for a wide range of industrial applications, even without considering the Reynolds number effect

The effect of hold-melt time of micro-regime precipitation size and hardness in Al-Cu alloy

This study aims to control the characterization and mechanical properties of smelting Al-Cu Alloy through Hold-Melt Time. This research uses aluminum scrap and copper wire scrap to produce quality as-cast ingots, clean the environment, and increase waste utilization. Copper melting point of 1083 °C is immersed in molten aluminum at a temperature of 900 °C for 10–30 minutes causing copper to dissolve in aluminum due to smelting events based on diffusion phenomena. Parameters of temperature and immersion time of copper in molten aluminum in this study are expressed by hold-melt time. In the copper aluminum alloy trade, commonly called Duralumin, it is commonly used for impact loads and is heat-treatable. Resistance to cryogenic temperatures, in the future Duralumin has the potential to replace stainless steel. This study used an electric resistance furnace with the specifications for smelting aluminum 3 kg, electric power 2.5–3.0 kW, electric voltage 220 Volts, maximum temperature 1000 °C. It had been conducted an experiment where copper had been melted under its melting point in duralumin ingot casting. In this study, copper pieces were soaked in liquid aluminum with temperature of 900 °C. After 10–30 minutes of holding melt, the soaked copper became Al-Cu alloys and was called molten Duralumin. After the molten duralumin had been cleaned from dross, it was poured into ingot casting. From specific weight test, more soaking time of the copper in liquid aluminum caused specific weight of ingot duralumin increase from 47.08 % to 57.56 % and its hardness increase from 93 to 113 BHN. This study contributes on melting energy saving and improves the characteristic and hardness of ingot aluminum type 2xxx