Aluminum Conductor Research Articles

Mechanically Robust and Thermally Conductive Nano-Porous Anodic Aluminum Oxide Templates via Thermal Stress Minimization and Alpha Phase Transformation for Interposer

Mechanically Robust and Thermally Conductive Nano-Porous Anodic Aluminum Oxide Templates via Thermal Stress Minimization and Alpha Phase Transformation for Interposer

Preparation and structure analysis of aluminum oxide/water glass/polyurethane composite grouting material for mining

In order to achieve safer and more efficient coal mining, the utilization of water glass/polyurethane (WG/PU) composite grouting material has become widespread in treating fractured coal mining faces. The reaction temperature and mechanical properties of WG/PU are crucial considerations that significantly impact safety and reinforcement effectiveness. However, reducing the reaction temperature without compromising the material's mechanical properties poses a challenge with conventional modification methods. Therefore, this study presents the development of a novel hybrid grouting material, namely Al2O3-WG/PU, which incorporates thermally conductive aluminum oxide (Al2O3) into WG/PU. The response surface method was employed to investigate the effects of key factors such as modules, mass ratio, Al2O3 content, and plasticizer content on the reaction temperature and compressive strength. Additionally, the static and dynamic compression properties of Al2O3-WG/PU were measured and analyzed. The morphology, elemental distribution, chemical composition, and valence information of the composite materials were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The results demonstrate that the introduction of A2O3 and scientific formula design reduces the maximum reaction temperature of Al2O3-WG/PU by 14.9 °C (12.7%). Although the percentage reduction may not seem significant, it represents substantial progress in the field of coal mine grouting materials. Moreover, this modification method not only maintains the material's mechanical properties but also enhances its compressive strength by 13.84 MPa (27.3%). Based on the characterization results, this study proposes a mechanism for temperature reduction and strength enhancement. The hybrid composite materials produced from Al2O3 and WG/PU show lower reaction temperatures and improved mechanical properties, presenting a promising solution for improving the safety performance of coal grouting materials.

Enhanced corrosion resistance of slippery liquid infused porous aluminum surfaces prepared by anodizing in simulated marine atmosphere

Transmission aluminum conductors in coastal areas are highly susceptible to corrosion by salt and acidic solutions, which leads to a decrease in the mechanical strength of the transmission conductors and even causes serious accidents of fracture. Traditional anti-corrosion methods have problems such as huge costs and low efficiency, and superhydrophobic coatings based on the lotus effect show poor durability. Herein, slippery liquid infused porous surface (SLIPS) for enhanced corrosion resistance was successfully prepared on 1060 pure aluminum (Bare) using anodizing combined with dimethyl silicone oil impregnation. The corrosion tendency and long-term corrosion resistance of SLIPS in simulated marine atmosphere were investigated. SLIPS exhibited the lowest corrosion tendency than Bare and anodic aluminum oxide (AAO). The corrosion current of Bare (7.85 × 10−7 A/cm2) was remarkably decreased by SLIPS to only 1.85 × 10−10 A/cm2. SLIPS showed excellent corrosion resistance in 14-day salt spray corrosion and 30-day simulated seawater immersion. After prolonged corrosion, SLIPS still displayed very low corrosion current and extremely high lubricant layer resistance. The corrosion weight gain of SLIPS was reduced by one order of magnitude than Bare. Under the synergistic effect of the aluminum oxide layer and lubricant, SLIPS presented certain self-healing performance and could maintain good anti-corrosion performance for a long time.

Influence of 1350 and 6201 aluminum alloys on the fatigue life of overhead conductors – A finite element analysis

Wires made of 6201-T81 aluminum alloy are generally more resistant to fatigue than AA1350-H19 (pure aluminum) wires. However, the fatigue lives of conductors composed of AA6201-T81 wires (All Aluminum Alloy Conductors) are lower than those of conductors made of AA1350-H19 wires reinforced with steel (Aluminum Conductor Steel Reinforced). From literature, the underlying reason for this behavior remains unclear. In this study, finite element simulations are carried out to understand the influence of the aluminum alloy type on the conductor life. To support the discussion, experimental data available in the literature for AAAC 900 MCM and ACSR Tern conductors, as well as for the aluminum wires made of alloys 6201-T81 and 1350-H19, are utilized. The study provides valuable insights into the intricate relationship between the tensile strength and fretting fatigue resistance of the 6201-T81 aluminum alloy and their impact on the fatigue resistance of 6201-based conductors. Specifically, it reveals that while the increased tensile strength of this alloy enables the critical wires in the conductor to withstand higher stress levels, its resistance to fretting fatigue falls short in compensating the damaging effects of such elevated stresses. As a consequence, greater fatigue damage occurs in these wires, ultimately leading to a reduction in the overall durability of the conductor. The findings of this study bring a new understanding to the fatigue problem of 6201-based conductors and have the potential to change the design guidelines for transmission lines using these cables.

Influence of calcium on specific heat capacity and changes in thermodynamic functions of aluminum conductor alloy AlTi0.1

Influence of calcium on specific heat capacity and changes in thermodynamic functions of aluminum conductor alloy AlTi0.1

Improved Mechanical Property and Corrosion and Wear Resistance of High-Voltage Aluminium Wires by Micro-Arc Oxidation Coating

New surface treatments are required to improve the resistance of high-voltage aluminium conductors to corrosion and wear. This paper describes the preparation of ceramic coatings on the surface of aluminium wires by the micro-arc oxidation (MAO) technology. The surface morphology, mechanical and tribological properties, electrical resistivity, wear and corrosion resistance of the MAO-treated aluminium samples are examined and compared not only with the untreated samples but also between the use of different current densities in the MAO process. The MAO treatment can increase the tensile strength of the wire and mitigate the wire elongation at excessive high temperature. In addition, the increased surface hardness and the overlapping micro-porous distribution of the MAO coating improve the resistance of the treated sample to wear and corrosion respectively, protecting the aluminium substrate from the joint effects of wear and corrosion. Furthermore, the MAO coating has little impact on the electrical resistivity of aluminium conductors and can mitigate the resistivity change due to corrosive damage. The MAO technology providing a potential idea for the surface treatment of aluminium conductors is expected to extend the service life and alleviate maintenance needs of aluminium conductors operating in harsh environments.

Insights into the Structural and Dielectric Behavior of Composites Produced from EPDM Waste Processed through a Devulcanization Method and SBR.

Ethylene propylene diene monomer (EPDM) is one of the most used polymers in the world. It is an elastomer, which means that the existing cross-linking between the main chains of the polymer created during the vulcanization process makes its recycling difficult. In this paper, a possible solution to this issue is studied. The devulcanization of EPDM is achieved by a thermomechanical process followed by microwave irradiation. These combined treatments suppress the cross-linking, yielding a material (EPDMd) that can be successfully blended to form composites. A common elastomer, styrene butadiene rubber (SBR), has been selected as the matrix. The new SBR/EPDMd composites can be useful as elastomeric dielectric materials and can contribute to the recycling of the discarded EPDM. To provide a better understanding of their microstructure and its relationship with their micro- and macroscopic behavior, samples containing 20 and 40% of EPDMd have been tested by thermogravimetric and dielectric analysis, focusing on variables such as the thermal properties of the blends, permittivity, electric modulus, conductivity, and activation energies. The results show interesting changes linked to the presence of EPDMd in the SBR matrix, such as the displacement of the β dielectric relaxation toward higher frequencies. The correct integration between the two phases is confirmed by the absence of any Maxwell-Wagner-Sillars type relaxation in their dielectric behavior. The presence of additives in the EPDMd samples has an effect on the conductivity, mainly due to the conductive aluminum silicate present in the EPDMd, which acts toward increasing some key dielectric features like conductivity and permittivity and decreasing the insulation of the final SBR/EPDMd materials. The inclusion of EPDMd also affects the α relaxations (low frequencies) and suppresses the β relaxations (high frequencies). The samples showed a non-Debye dielectric behavior. In short, a compact and well-integrated material with a dielectric behavior is created, which exhibits interesting differences from the reference SBR matrix. Finally, it is concluded that the compounds tested are suitable for applications as electrical insulators.

Atomically Resolved Structure of the Directly Bonded Aluminum–Carbon Interface in Aluminum–Graphite Composites by Solid-State Friction Stir Processing: Im plications for a High-Performance Aluminum Conductor

Atomically Resolved Structure of the Directly Bonded Aluminum–Carbon Interface in Aluminum–Graphite Composites by Solid-State Friction Stir Processing: Im plications for a High-Performance Aluminum Conductor

Ice monitoring of aluminum conductor steel-reinforced cables using guided waves

Aluminum conductor steel-reinforced (ACSR) cables are commonly used as power transmission conductors. In cold regions, icing of ACSR cables is a common problem. Ice accretion on ACSR cables may cause various problems. Timely ice monitoring is a primary measure for any type of de-icing solution. In this study, a guided wave-based method was proposed to monitor the ice-forming processes on ACSR cables owing to its advantages of high sensitivity and long-range inspection. The dispersion curves were first obtained using the semi-analytical finite element (SAFE) method for the ACSR cross-section geometry, particularly for different ice thicknesses. They could be used to accurately determine the group velocity for each guided wave mode. Subsequently, a series of tests were conducted with different ice thicknesses in the laboratory. Guided waves were excited by an electromagnetic acoustic transducer (EMAT) in ACSR cables. A new method that combined principal component analysis (PCA) and empirical mode decomposition (EMD) was employed to process the original guided wave signals to obtain effective icing indicator. The results obtained by the guided wave-based method were verified using an image-based method. This study indicates that the proposed ultrasonic guided wave combined with the PCA–EMD method is efficient and sensitive for the ice monitoring of ACSR cables.

Effect of Er, Si, Hf and Nb Additives on the Thermal Stability of Microstructure, Electrical Resistivity and Microhardness of Fine-Grained Aluminum Alloys of Al-0.25%Zr.

The conductor aluminum alloys of Al-0.25wt.%Zr alloyed additionally with X = Er, Si, Hf and Nb were the objects of our investigations. The fine-grained microstructure in the alloys was formed via equal channel angular pressing and rotary swaging. The thermal stability of the microstructure, specific electrical resistivity and microhardness of the novel conductor aluminum alloys were investigated. The mechanisms of nucleation of the Al3(Zr, X) secondary particles during annealing the fine-grained aluminum alloys were determined using the Jones-Mehl-Avrami-Kolmogorov equation. Using the Zener equation, the dependencies of the average secondary particle sizes on the annealing time were obtained on the base of the analysis of the data on the grain growth in the aluminum alloys. The secondary particle nucleation during long-time low-temperature annealing (300 °C, 1000 h) was shown to go preferentially at the cores of the lattice dislocations. The Al-0.25%Zr-0.25%Er-0.20%Hf-0.15%Si alloy subjected to long-time annealing at 300 °C has the optimal combination of microhardness and electrical conductivity (59.8%IACS, Hv = 480 ± 15 MPa).

Mechanisms of air breakdowns for aluminum conductors steel reinforced wire-wire gaps induced by propane jet flames

In recent years, events of transmission line tripping caused by wildfires have occurred frequently in many mountain areas. In order to understand the mechanism of such events, an experimental system for simulating breakdown discharge processes of model wires induced by a simulated fire source is designed. In this experiment, propane jet flame (somewhat like eruptive fires in real wild fires) is used as a simulated flame source. By setting three different gas flow rates and five different wire-wire gaps, discharge breakdown behaviors and characteristics between two ACSR (aluminum conductors steel reinforced) segments in propane flames with three flame zones are explored. The influences of these different factors on the breakdown characteristics and mechanisms of wire-wire air gaps are analyzed. Results show that breakdown voltages increase almost linearly with the increase of wire-wire gaps in continuous zone of the flames for three gas flow rates. For a short wire-wire gap like 5.0 cm, the pilot discharge channels can be formed more easily, stably and completely under a lower voltage and weaker external ionization environment. The propane jet flame conditions are complex and affected by multiple actions like initial jet force (affected by gas flow rate), temperature distribution, soot particle, ion wind. As a result, local electric field will be distorted, a streamer channel is established dependently in different cases. These factors play individual, competitive or synergistic roles at the same time in breakdowns of real ACSR wire-wire gaps.

Scalable, ultra-high stretchable and conductive fiber triboelectric nanogenerator for biomechanical sensing

A reliable energy device for wearable products and soft electronics must meet the essential needs of high stretchability, stable performance and easy to integration. Despite the substantial advances in material and structural design of two-dimensional planar energy devices, fiber-based electronics remains restricted to scalable fabrication and low conductivity due to the challenges in manufacturing technologies. Herein, we report a homogeneous wet-spun fiber with scalable fabrication and tailorable knittability by in-situ copolymerization dopamine-modified MXene (P-MXene) marring with MXene/TPU (MP) fibers (MMP). The resulting exhibit high stretchability (∼ 675%), good conductivity (4.32 S cm−1) and reliable stability under large deformation thanks to the superior deformation recovery properties of TPU and reliable electrical conductivity of P-MXene ink. Furthermore, the breathable and hydrophobic properties are achieved by a scalable integration of as-prepared fibers due to the porous structure and inherent properties of plain fabric. A fiber-based triboelectric nanogenerator (TENG) constructed by the designed fabric from conductive MMP fiber and aluminum foil shows a maximum open-circuit voltage, short-circuit current and power density of 20.1 V, 0.92 μA and 0.16 mW m−2, respectively. Interestingly, the fiber-based TENG proved a capable to stabilized electrical energy output over 100 times bending with no significant attenuation of voltage signals. As a proof-of-concept, the scalable integrated fabric is used for energy harvesting and human motion sensing via simultaneously real-time responds of electrical signals. This strategy that integrating generators and active sensors simultaneously provide new insights for the development of advanced wearable energy devices, intelligent fabrics, and human-computer interaction.

Facile Deposition of the LiFePO4 Cathode by the Electrophoresis Method.

Lithium iron phosphate (LiFePO4, LFP) is one of the most advanced commercial cathode materials for Li-ion batteries and is widely applied as battery cells for electric vehicles. In this work, a thin and uniform LFP cathode film on a conductive carbon-coated aluminum foil was besieged by the electrophoretic deposition (EPD) technique. Along with the LFP deposition conditions, the impact of two types of binders, poly(vinylidene fluoride) (PVdF) and poly(vinylpyrrolidone) (PVP), on the film quality and electrochemical results has been studied. The results revealed that the LFP_PVP composite cathode had a highly stable electrochemical performance compared with the LFP_PVdF counterpart due to the negligible influence of the PVP on the pore volume and size and retaining high surface area of LFP. The LFP_PVP composite cathode film unveiled a high discharge capacity of 145 mAh g-1 at 0.1C and performed over 100 cycles with capacity retention and Coulombic efficiency of 95 and 99%, respectively. The C-rate capability test also revealed a more stable performance of LFP_PVP compared to LFP_PVdF.

The performance of thermally conductive tree-like cast aluminum structures in PCM-based storage units

The thermal performance of a latent heat storage unit was tested during cyclic operation, with LiNO3-KNO3-NaNO3 eutectic as the phase change material. The heat transfer was enhanced by the utilization of a tree-like aluminum structure, cast by means of two combined technologies: polymer 3D printing and investment casting. The mixture of salts was subjected to DSC analysis, to establish the thermal effects during heating and cooling. The unit was tested with and without the enhancer to determine the temperature response and distribution during working cycles (charging–discharging). The experimental outcomes were compared with the results of a numerical simulation performed using the Flow 3D program. To protect the metallic structures from the aggressively corrosive environment of molten salts, they were covered with plasma electrolytic oxidation (PEO) ceramic coatings. The influence of the coating on the heat transfer ability was also evaluated.

Analysis of Temperature Rise Characteristics and Fatigue Damage Degree of ACSR Broken Strand

In this paper, the research on ACSR temperature of broken strand and fatigue damage after broken strand is carried out. Conduct modeling and Analysis on the conductor through Ansoft Maxwell software. The distribution of magnetic force lines in the cross section of the conductor after strand breaking and the temperature change law of the conductor with the number of broken strands are analyzed. A model based on electromagnetic theory is established to analyze the distribution of magnetic lines of force in the cross section of the conductor after strand breaking and the temperature variation law of the conductor with the number of broken strands. The finite element analysis results show that with the increase in the number of broken strands, the cross-sectional area of the conductor decreases, the magnetic line of force of the inner conductor at the broken strand becomes denser and denser, and the electromagnetic loss of the conductor becomes larger and larger. Therefore, the temperature of the conductor at the broken strand becomes higher and higher. Then, the current carrying experiment of conductor is carried out for LGJ-240/30 conductor. It is found that the temperature rise at the junction of inner and outer layers at the broken strand is particularly obvious, and the temperature of inner aluminum conductor at the broken strand also increases with the increase of broken strand. According to the analysis of experimental data, with the increase of broken strands, the antivibration ability and service life of the conductor decrease. At the same time, under certain conditions of broken strand, the fatigue life of conductor increases with the increase of temperature.

Implementation of Lean Manufacturing for Increasing the Quality of Aluminum Conductor Products in the Stranding Process with the DMAIC and VSM Method Approach: A Case Study in Electrical Manufacturing Component

ElectricalCompany in this study is a manufacturing company engaged in the cable industry and one of the products it produces is an aluminum conductor. The current situation shows that the quality of aluminum conductor products still does not meet thecompany's standards. This can be seen from the production output data for the period June 2021 –November 2021 where the percentage ofaluminum conductor product faiuresexceeds the set target of 1.50%. The purpose of this research is to implement lean manufacturing to improve the quality of aluminum conductor products using the DMAIC (Define, Measure, Analyze, Improve, Control) and VSM (Value Stream Mapping) methods. The expected result of this research is an increase in product quality.

THE SUBTRACTIVE PROCESS OF FORMING A METALLIZATION SYSTEM.

The subtractive process of forming a metallization system for integrated circuits has been studied. Structures with aluminum and copper conductors with different pitches were used as models. The gaps between the conductors were filled using the chemical solution deposition technique. The formed organosilicate layers provided complete or partial planarization of the relief. Electrical measurements indicated a decrease in capacitance and leakage currents in structures with nanoporous dielectric layers.

Internal Defect Detection of Overhead Aluminum Conductor Composite Core Transmission Lines With an Inspection Robot and Computer Vision

Overhead aluminum conductor composite core (ACCC) transmission lines are extensively used. However, internal defects of ACCC wires are difficult to detect, threatening the stability and security of the grid. Thus, a novel automatic detection system using an X-ray inspection robot and an anchor-free object detection model is proposed to solve the problem of detecting internal defects in ACCC wires. First, a new inspection robot with a nondestructive testing (NDT) system consisting of a digital radiography (DR) detection panel and a portable X-ray generator is developed to acquire X-ray images of ACCC wires. Then, the IN-ACCC dataset is created by collecting the X-ray images of artificial defective ACCC wires and then processing, classifying, and labeling the images. Finally, an anchor-free object detection model named CenterNet-NDT is proposed based on CenterNet for high-performance identification of internal defects. CenterNet-NDT has a specially designed feature fusion module composed of SPPCSPC, polarized self-attention (PSA), and a newly weighted bidirectional feature pyramid network named SOFPN. Compared with some state-of-the-art methods and CenterNet with different modules, the proposed CenterNet-NDT achieves the highest mAP of 90.60% on the IN-ACCC dataset. The proposed automatic internal defect detection system is verified to be effective and robust by lab experiments and has been repeatedly applied in actual ACCC transmission line inspection tasks to reduce the safety hazards of wire breakage.

DESIGNING A 34.5 kV DISTRIBUTION NETWORK WITH SUPERCONDUCTORS AND COMPARISON WITH THE EXISTING SYSTEM

Aim: Electrical energy goes through many different stages from its generation to delivery to the end user. In the transmission and distribution processes of the electrical energy, the energy losses may occur. It is essential to seek appropriate solutions to minimise the electrical power losses and to eliminate all parameters that impair the quality of energy so as to help the electrical network system can operate efficiently, economically, reliably and sustainably. In this study, a medium voltage distribution network and of all parameters were modelled and examined in the computer environment. Modelling and analysis processes were done through the DigSilent Power Factory program which can perform power system analyses. Method: The study consists of three stages. In the first stage, Rabak Feeder modelling of Izmit TM and some analyses of this feeder were made in the DigSilent program. In the second stage, all the underground aluminium conductors in Rabak Feeder were replaced with the superconductors and were modelled and analysed in the DigSilent Power Factory program. In the third stage, Rabak Feeder was redesigned with the superconductors and analyses were made. Results: As a result of these analyses, all parameters of the models were examined. The parameters obtained from the existing and the other two-stage models were compared. These comparisons show that the efficiency of the system increases while the voltage drops and energy losses both decrease when the superconductors are used. Conclusion: The use of the superconductors has increased the efficiency of the system by reducing the voltage drops and energy losses.

Bioinspired hollow porous fibers with low emissivity and conductivity aluminum platelet skin for thermal insulation

Hollow porous fibers with low emissivity and conductivity aluminum platelets skin for thermal insulation.