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2024 aluminum alloy has high strength, processing performance, and good damage tolerance performance, but it is prone to intergranular corrosion and pitting. Therefore, the development of corrosion protective coatings is essential for the aluminum alloy. In this paper, cerium ion (Ce3+) was doped into chitosan‐modified montmorillonite (Ce‐CS‐MMT) by ion exchange method, and the corrosion protective performance of Ce‐CS‐MMT epoxy coating (Ce‐CS‐MMT/EP) was investigated. The electrochemical analysis of aluminum alloy in cerium‐containing solution showed the corrosion inhibition efficiency reached 95.52%. The result indicates the corrosion inhibition effect of cerium‐containing solution was better than pure NaCl solution and MMT solution. The corrosion study of the coating illustrates that the protection rate of Ce‐CS‐MMT/EP reached 95.82%, which was higher than that 91.83% of Ce‐MMT/EP. The result indicates the resistance of charge transfer was greater and the better shielding effect for electrolyte corrosion ions than MMT and Ce‐MMT epoxy coatings, and the corrosion protective performance was excellent. [ABSTRACT FROM AUTHOR]

This paper presents a numerical study of topology-optimised pin-end aluminium alloy columns using finite element analysis (FEA). The FEA models integrate geometric imperfections and material nonlinearity, and are validated against experimental findings from the existing literature. ABAQUS v.6.15 (release 2020) is used in preparing the FEA models and obtaining the analysis results. Furthermore, modern design methodologies including Eurocode 9, the direct strength method (DSM), and the continuous strength method (CSM) are employed to assess the maximum load capacity of such columns. Parametric investigations encompass diverse parameters such as varied cross-sections, column lengths, and global and local imperfections. By analysing a total of 288 FE models, incorporating 16 column cross-sections across two lengths with nine distinct imperfections, this study compares results with those derived from modern design methodologies. Thus, this research elucidates the behaviour of novel cross-sections and the application of contemporary design techniques in their analysis. [ABSTRACT FROM AUTHOR]

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Energy dispersive X-ray fluorescence spectrometry (ED-XRF) is evaluated as an alternative to conventional acid-mediated soil digestion methods for analysis of aluminum (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), silicon (Si), strontium (Sr), titanium (Ti), and zirconium (Zr). The Kellogg Soil Survey Laboratory (KSSL) currently uses microwave-assisted digestion with inductively coupled plasma – atomic emission spectrometry (ICP-AES) to measure the 12 elements (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Sr, Ti, Zr). The equipment needed to conduct the digestion method is expensive, the materials are hazardous, and the method is laborious. The Kellogg Soil Survey Laboratory (KSSL) has observed variable elemental recoveries for certain elements. The objective of the study was to evaluate an ED-XRF method as an alternative to the KSSL digestion method. The literature offers few examples of X-ray fluorescence (XRF) method development and validation. The candidate ED-XRF method offered a more efficient, less expensive, and less hazardous approach for measuring the 12 elements. Relative to the digestion method, the candidate ED-XRF method showed improved precision and accuracy for specific elements. [ABSTRACT FROM AUTHOR]

The inherent instability of laser welding, particularly keyhole instability, poses significant challenges in industrial applications, leading to defects such as porosities that compromise weld quality. Various forces act on the keyhole and molten pool during laser welding, influencing process stability. These forces are categorized into those promoting keyhole opening and penetration (e.g., recoil pressure) and those promoting keyhole collapse (e.g., surface tension, Darcy's damping forces), increasing instability and defect likelihood. This paper provides a comprehensive instability analysis to uncover key factors affecting keyhole and process instability, presenting future avenues for improving laser welding stability. Using a novel numerical method for simulating laser spot welding on aluminum with COMSOL Multiphysics 5.6, we investigated the effect of laser pulse shaping on keyhole and process instability. Our analysis focused on keyhole morphology, fluid flow behaviour, and force analysis. The results indicated that the curvature effect, Marangoni effect, and Darcy's damping force are primary contributors to instability, with the curvature effect and Darcy's damping force being the most dominant. Additionally, erratic and high-velocity magnitudes induce intense fluid flow behaviour, exacerbating keyhole instability. Moreover, single/quadruple peak triangular and variant rectangular ramp-down pulse shapes produced the least instability, while multi-pulse rectangular shapes exhibited intense instability. It was found that combining triangular/rectangular pulse shapes can reduce force and keyhole instability by smoothing spontaneous force spikes, resulting in a more stabilized welding process. Controlling fluid flow and abrupt force changes with appropriate pulse shaping is key to defect-free welded products. [ABSTRACT FROM AUTHOR]

This study conducted molding process research on castings of complex engine blocks with a new Al–Si–Cu aluminum alloy material. Numerical simulation and experimental validation were used to investigate the effects of different pouring system design schemes on the casting performance, defect formation and mechanical properties of aluminum alloy castings. Based on the casting structure and alloy casting properties, three types of casting systems (i.e., A, B, and C) were designed and analyzed by numerical simulation and testing. The study shows that the molding process of casting system scheme C is more optimal, the numerically simulated porosity is reduced by 4.13 and 1.9% compared with those of schemes A and B, respectively, the defect volume is reduced by 205.87 and 94.7 cm3 compared with those of schemes A and B, respectively, and the average cooling rate is improved by 47.6 and 26.5% compared with those of schemes A and B, respectively. After experimental verification, casting system C exhibited optimal mechanical properties, good CT scan and the microstructure of aluminum alloy analysis results, and numerical simulation results consistent with the actual trial production results, providing guidance for relevant theoretical research. [ABSTRACT FROM AUTHOR]

In the impact application, the impactor doesn't have to be perpendicular to the structure. This study mainly focuses on numerical low velocity oblique impact analysis performed on silicon aluminum composite foam using ABAQUS®. In this paper, the shear failure model is used to estimate damages in silicon aluminum composite foam model for different angles of the impactor. Here, dissipation energies, impact load histories and load displacement curves for damages under different angles of impactor have been characterized. From the study, it is found that the contact force intensity and penetration time decrease as the angle of the impactor increases. In the study of energy time histories, it is seen that energy increases and penetration time decreases as the angle of the impactor increases. From the contact force study, it is found that the contact force decreases, and contact time increases as the angle of the impactor decreases. The studies for displacement show that oblique impactor displacement increases as the angle of the impactor increases. [ABSTRACT FROM AUTHOR]

This study focused on optimizing the process of CNC machining to enhance productivity and product quality of surface finish Ra via the process parameters of the cutting speed (vc), feed rate (vf), and cutting depth (doc). Experimentation was performed on workpieces of AA-6061 to investigate the response Ra through variation of the process parameters to analyze their best fit using RSM with 2³ full factorial designs L-8 of DOE. The analysis of variance (ANOVA) was then used to find the major contributors among them that were responsible for the Ra. Based on the result, better Ra was obtained at 0.103 µm using the best fit of vf (150 mm/min), vc (220 m/min), and doc (0.1 mm). ANOVA shows vf contributed better Ra followed by vc and doc respectively. In addition, the level of Ra's was analyzed through contour plots represented by different colours. It continued to analyze the effect of the process parameters via the main effects plot, Pareto chart, and the contour plot in the predictive desirability model, which indicated that the plots and chart confirmed the vf had more influence compared to others. The study confirmed that the low-level parameters provided better Ra to be used for polishing. [ABSTRACT FROM AUTHOR]

In this study, we successfully obtained crystalline silicon from silica powder using a metal-induced crystallization method. For this purpose, powders were first prepared from organosilicon compounds and finely dispersed aluminum particles, then their metal-induced crystallization was carried out by annealing at the temperature of 570 °C. Powders of organosilicon compounds (tetraethoxysilane and polyethylhydrosiloxane) were prepared by different technological operations in order to determine precisely the presence of carbon in the product. The results showed that the presence of carbon in silica powder affects the production of crystalline silicon. In silica powders containing no carbon, the formation of crystalline substances does not occur at the annealing temperature of 570 °C. The results of this study are of great importance for the production of polycrystalline silicon powders obtained at reduced temperatures. [ABSTRACT FROM AUTHOR]

In magnetic pulse welding, the deformation phenomenon of a moving sheet is divided into the deformation and continuous collision processes, then, the deformation analysis of the sheet is performed by using a magnetic pressure delivered to the sheet. When applying the pressure provided by neglecting an electric field generated during the deformation of the sheet, the calculated values accord only with one point for many measured values of both deformation height and deformation velocity, and errors greatly increase as the calculated values deviate from the point according. The new magnetic pressure corrected using a pressure drop coefficient is introduced because the deforming sheet leads to a drop in the pressure. If a successive approximation is applied to the deformation analysis, many calculated values approach the standard measured values. The calculated values are within a small error range for the measured values at 17 out of 18 points. It has been clarified that the deformation of the moving sheet is estimated fairly accurately by using the successive approximation. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the heavy metal pollution status of the agricultural soils in Ramhormoz Plain, Khuzestan province, Iran. A total of 54 samples from the depths (0–20 cm) of the soil were collected from the selected areas in (March) 2021. According to the obtained results, the concentrations of As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Al in soil samples were 1.3, 0.68, 60, 10.6, 0.01, 218, 23, 3.65, 14 and 0.58 mg/kg, respectively, in which As showed significant soil contamination and Cu, Hg, Mn, Ni, Pb, Zn and Al moderate contamination according to the calculation of contamination factor (CF). PCA analysis revealed that both anthropogenic and natural sources of pollution like agricultural and transport activities contributed to the enrichment of study area. Investigation of ecological risk indicated that Ramhormoz Plain was categorized as a high risk area. [ABSTRACT FROM AUTHOR]

A combination of fixed dose tablet containing 0.5 mg lobeglitazone sulfate (LBZ) and 1 mg glimepiride (GLM) has demonstrated efficacy in enhancing glycemic control in diabetes. The projected work aimed to develop and validate a high‐performance thin‐layer chromatographic (HPTLC) methodology for the precise quantification of both the drugs in tablet formulations. The HPTLC analysis utilized aluminium plates layered with silica gel 60F254, and the solvent system consisted of ethyl acetate, benzene, and hexane (4:3:1 v/v/v) followed by densitometric scanning at 238 nm. The Rf value was found to be 0.68 ± 0.001 for LBZ and 0.48 ± 0.002 for GLM. The methodology exhibited linearity in the range of 100–2000 ng/band for LBZ and 200–4000 ng/band for GLM, with correlation coefficients of 0.9988 and 0.9981, respectively. Exceptional sensitivity was observed, with detection limits of 23.86 ng/band for LBZ and 58.26 ng/band for GLM, along with quantification limits of 72.32 ng/band for LBZ and 176.55 ng/band for GLM. The method demonstrated precision (% relative standard deviation of peak area < 2) and accuracy (recovery between 97% and 102%). The suggested method is suitable for quantifying both the drugs in tablets, making it useful for routine quality control in laboratories. [ABSTRACT FROM AUTHOR]

The proposed research work is to develop the brick by incorporating steel industry industrial waste to achieve sustainable environment. Aluminium dross (AD) is the one of the major waste produced during aluminium ingots production. Particle size and chemical compositions of aluminium dross are analysed using Scanning Electron Microscopy (SEM). To effectively utilise the aluminium dross, five mix composition of bricks were produced to determine the influence of AD on mechanical properties of bricks such as the compressive strength, water absorption, efflorescence and bulk density. Mix B gives the maximum compressive strength of 11.54 N/mm2, water absorption of 5.6% and bulk density of 1658.4 kg/m3 for the mix of 5% dross. Analysis of variance (ANOVA) is employed to analyse the influence of dross and fly ash concentrations on the quadratic model. [ABSTRACT FROM AUTHOR]

The shape and structure of helicopter fuselage are complex, and it is difficult for a finite element method (FEM) to investigate helicopter fuselage projectile damage in a multi-projectile environment. An efficient analysis method for helicopter fuselage projectile damage is then proposed by coupling the projectile breakdown theory, which is derived from the existing empirical formula for penetrating ductile metals, and the model of projectile impact. Then, the characteristics of the helicopter fuselage impact coordinate, residual velocity, and fuselage damage area under a multi-projectile attack are investigated. The results show that the predicted residual velocities agree with the experiments. The maximum errors of the residual velocity and the fuselage damage area are 4.7% and 9.56%, respectively. Compared with the FEM, the computational time of the proposed method is reduced by 92.1%, and its efficiency is obviously improved. As the incidence angle increases, the residual velocity decreases, and the damage area increases. When the incidence angle of the projectile body is large, the projectile body cannot penetrate the surface of the fuselage, resulting in flume skid damage and a large area of damage. [ABSTRACT FROM AUTHOR]

Aluminum metal matrix composites find applications in several industries, such as aerospace, military, cars, sports equipment, and electronics. The primary objective of this experimental study is to obtain insights into the microstructural properties of an Al-Zn alloy that has been strengthened with copper. This investigation involved the preparation of an alloy including aluminum and zinc, which was afterward reinforced with varying quantities (0%, 0.4%, 1.2%, and 2%) of copper. In addition to conducting XRD tests to investigate the crystallite structure, particle size, and microscopic strain of the samples using the Scherrer and Williamson-Hall models, structural examinations were carried out using the EDS test to ascertain the elemental composition proportions. It was observed that the alloy (A-Zn-0.4%Cu) has smaller particle sizes than the other alloys under consideration. [ABSTRACT FROM AUTHOR]

The simultaneous increase in strength and plasticity of aluminum and its alloys at cryogenic temperatures has been shown in previous research, but the deformation mechanism was still unclear. Therefore, the purpose of this investigation was to reveal the relationship between slip behavior and mechanical response at low temperatures. A quasi-in situ scanning electron microscope was used to observe the evolution of slip bands in the selected aluminum single crystals with two typical orientations at 25 °C, −100 °C, and −180 °C. The results showed that irrespective of orientation, the density of the slip plane was increased with the decline in temperature, which inhibited slip localization and significantly improved plasticity and work hardening. In detail, at RT, the slip bands were widening until the micro-cracks were generated, causing early failure during deformation. When the temperature was decreased to −180 °C, the slip plane density was increased, and the deformation was more homogenous. Moreover, the slip mode was influenced by orientation and temperature. In particular, a single slip system was activated in the sample with the [112] orientation at all the temperatures investigated. Multiple slip systems were found to activate at 25 °C and −100 °C, and only the primary slip system was activated in the sample with [114] orientation at −180 °C. These findings deepen the understanding of slip behavior at cryogenic temperatures, providing new insights into the deformation mechanism of aluminum and its alloys. [ABSTRACT FROM AUTHOR]

Due to the coexistence of Al3+ and RE3+ and their similar properties, the separation of aluminum from rare earths is difficult. In this study, selective precipitation was used to separate aluminum from rare earth chloride solution via electrochemical regulated hydrolysis. By controlling the current density and electrolytic time, the rate of hydroxyl ion production was regulated, and the selective separation of rare earth and aluminum was realized according to the different precipitation sequences. By altering the temperature, current density, pH value, and other parameters, the separation performance of aluminum from rare earth in mixed rare earth chloride systems was systematically investigated. The removal rate of aluminum reached 88.35%, and the loss rate of rare earth was only 5.99% under optimized conditions. Compared with traditional neutralization hydrolysis, the new process showed higher efficiency and lower rare earth loss rate. Furthermore, a kinetic analysis of aluminum precipitation revealed that the reaction adhered to pseudo-first order kinetics. Additionally, the precipitate obtained via separation and filtration was amorphous alumina hydroxide with a small amount of rare earth attached. No reagent was consumed for the new process, which was more efficient and cleaner, providing a new idea for removing aluminum impurities from rare earth solutions. [ABSTRACT FROM AUTHOR]

Aluminum alloy offers the advantages of being lightweight, high in strength, corrosion-resistant, and easy to process. It has a promising application prospect in large-span space structures, with its primary application form being single-layer reticulated shells. In this study, shaking table tests were conducted on a 1/25 scale aluminum alloy single-layer spherical reticulated shell structure. A finite element (FE) model of the reticulated shell structure was established in Ansys. Compared with the experimental results, the deviation in natural frequency, acceleration amplitude, and displacement amplitude was less than 20%, confirming the validity of the model. An extensive analysis of the various rise–span ratios and connection constraints of a single-layer spherical reticulated shell structure was carried out using the proposed FE model. The experimental and simulation results showed that as the rise–span ratio of the aluminum alloy reticulated shell increases, the natural frequency of the reticulated shell structure also increases while the dynamic performance decreases. The connection of the circumferential members changes from a rigid connection to a hinged connection. The natural frequency of the reticulated shell structure is reduced by about 40% while the acceleration and displacement response values are decreased by approximately 15%. [ABSTRACT FROM AUTHOR]

Xerogels and powders of solid solutions based on zirconium dioxide are synthesized by the method of the coprecipitation of hydroxides from aqueous solutions of nitrate salts of zirconium, yttrium, aluminum, and cerium with an aqueous solution of ammonia. The characteristics of the resulting materials are studied. The influence of stabilizers and additives on their synthesis, sintering, and properties is assessed. [ABSTRACT FROM AUTHOR]

Using bolts through the back of a solar photovoltaic (PV) module frames to attach them to racking is time consuming and awkward, so commercial PV installations use clamping technologies on the front. Conventional and proprietary clamps are costly and demand access to supply chains for uncommon mechanical components that limit deployment velocity. To overcome these challenges, this study presents new open-source downward-fastened and side-fastened aluminum (Al) framing designs, which are easy to install and compatible with metal and wood racks. The proposed parametric open-source designs are analyzed through finite element method (FEM) simulations and economic analysis is performed to compare to conventional PV frame at both the module and system levels. The FEM results showed all the frames have acceptable mechanical reliability and stability to pass IEC 61215 standards. The results show the new frame (with a bottom width of 29 mm and thickness of 1.5 mm) has about a 2% land use efficiency penalty, but has better mechanical stability (lower stress and deflections), is easier to install, and has reduced material economic costs compared to conventional frames. The results are promising for the use of the new PV frame designs for distributed manufacturing targeted at specific applications. [ABSTRACT FROM AUTHOR]

Bipolar plates are the key component in polymer electrolyte membrane fuel cells (PEMFCs), which ensure the low cost of the fuel cell stack and furnish some of the important applications such as distributing the reactant gases, conducting the electrons, and removing the waste heat in PEMFCs. Thus, metallic bipolar plates (BPs), such as aluminum (Al), have attracted immense consideration and afford better performance in different machine‐driven applications and mass manufacturing opportunities. In order to increase the corrosion resistance of Al BPs, several methods are used and conducted by scientists. The corrosion behavior and surface structure analysis of pure Al were studied through the immersion process in fluoride‐sulfate solutions, assuming its use as BPs in PEMFC‐produced water. The open cell voltage, interfacial contact resistance, and polarization tests and the fuel cell operations were performed to evaluate cell voltage, current density, corrosion resistance, and the effect of fluoride and sulfate ions on the BPs in PEMFC. The hydrophobicity character of the surface of Al BPs was observed by the measurement of the wettability test. The atomic force microscopy images were taken to study the surface roughness, which was correlated with the corrosion rates of Al BPs. In addition, the amount of corrosion was calculated after 24–120 h of immersion in fluoride‐sulfate solutions. The scanning electron microscopy, transmission electron microscopy, and energy‐dispersive X‐ray spectroscopy data were analyzed to investigate the surface structure, morphology, and elemental analyses. Thus, the results found in this study revealed that Al‐based materials can be suitable for BPs in PEMFCs. Furthermore, it is noticed that the amount of corrosion was influenced by the presence of even a very small amount of fluoride ions present in the PEMFC environment, while it was suppressed efficiently by sulfate ions. [ABSTRACT FROM AUTHOR]

Stearic and phenyl-phosphonic acids were applied to fine aluminum particles to understand their effect on the surface chemical composition and bulk properties of the surface-treated powders. During the solution phase deposition process, the surface composition changes chemically through a condensation reaction between the acid and particle surface hydroxyl groups, forming covalent chemical bonds. The retention of both types of acids was verified through characterization using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The presence of stearic acid on the particle surface was observed through signature absorbance peaks, including interfacial C-O bonding modes, carboxylate, and carbonyl moieties, all present on both the treated powder. Spectra using XPS showed an increase in -CH relative intensity signal on the particle surface when compared to the raw material when considering the the carbon 2p photoelectron peak. Similar findings confirmed the presence of the phenyl-phosphonic acid when comparing to the raw material. The IR spectrum confirmed the presence of P-O-Al, P-O, and phosponates as a result of the surface bonding between the reagent and particles. XPS always provided evidence through the presence of phosphorous 2p and 2s photoelecton peaks at 191.3 and 133.4 eV, respectively. The bulk properties of both surface treated powders improved, as shown through improved apparent/tap density and a decreased Hausner Ratio (Group C to Group A behavior). Rheological characterization provided additional evidence by showing a reduced specific energy, flow rate index, and cohesion. The particle packing was improved as evidenced through reduced compressibility as a function of applied normal stress. [ABSTRACT FROM AUTHOR]

Despite being a non-essential metal in the body, we acquire aluminium via various sources such as aluminium cookware, foil, medicines, cosmetics, food, water, and aluminium-industries. Though it can be eliminated from our body, the excess and cumulative effect can't be ignored. Aluminium load above the threshold causes several diseases like Alzheimer's, osteomalacia, anaemia, and cancer. Hence, the current study was designed to explore the frequency of aluminium usage in various forms in the Indian population of northwest rural and urban regions of Maharashtra and investigate any preferential difference in aluminium usage with occupation, education, income, and family structure. It is a correlational study designed to check the extent of aluminium involvement in their lives and their perception of awareness. A non-random sampling method using social media was utilized for data collection, and data were analyzed using a statistical tool, Jamovi. A survey-based analysis of the responses to a pre-designed questionnaire was done. The prominent factor contributing to the aluminium load was found to be the aluminium vessel used in our kitchen. Boiling, storing, and baking edible items facilitate its leaching into food to toxic levels. Further analysis revealed a significant correlation of financial and educational status with aluminium usage. Reducing aluminium vessel usage for cooking can significantly reduce aluminium load in our bodies. However, we still need to be vigilant about the aluminium load which the other products are imparting upon us. Hence, awareness and exploring the alternatives are the only options to keep a check on the aluminium load. [ABSTRACT FROM AUTHOR]

A condenser used in a power plant failed due to a leak of cooling water from inside the tubes. This paper details the subsequent investigation and the conclusions reached. The cause of the failure of the condenser tubes was due to plug-type dezincification and stress corrosion cracking (SCC). The root cause of the failure was found to be associated with the presence of deposits on the inner surface of the tubes. These deposits were formed by a low velocity of the cooling water and poor cleaning of the interior of the tubes. The failure process was favored by an inappropriate choice of material and poor metallurgical quality of the tubes, manifested in a non-uniform grain size structure to enhance corrosion sensitivity beneath deposits. [ABSTRACT FROM AUTHOR]

This study investigates landfill leachate treatment using aluminum (Al-Al) and iron (Fe-Fe) electrodes in electrocoagulation (EC). Aluminum experiments revealed COD removal percentages of 22% (pH 7.4) and 20% (pH 6.0), while iron demonstrated higher efficiency at 32% (pH 7.4) and 30% (pH 6.0). Both processes excelled at neutral pH, with Fe-Fe EC displaying superior removal efficiency. To address electrode passivation, external aeration improved COD removal (31% to 61%) under specific conditions (3 V, pH 7.4, 60 min). The EC process established a neutralization mechanism, eliminating the need for further treatment before discharge. External aeration and polarity changes at intervals mitigated passivation, enhancing COD removal (61% to 69%). Voltage testing (1 V, 3 V, 5 V, 7 V) revealed a direct correlation, peaking at 91% efficiency with 5 V. Specific energy consumption was 2.34 kWh g−1, and sludge generation varied with voltage. The combined use of external aeration and polarity shifts resulted in 270 ml of sludge, demonstrating improved efficiency in the EC process. [ABSTRACT FROM AUTHOR]

In this study, the Raman biaxial stress coefficients KII and strain-free phonon frequencies ω0 have been determined for the E2 (low), E2 (high), and A1 (LO) phonon modes of aluminum nitride, AlN, using both experimental and theoretical approaches. The E2 (high) mode of AlN is recommended for the residual stress analysis of AlN due to its high sensitivity and the largest signal-to-noise ratio among the studied modes. The E2 (high) Raman biaxial stress coefficient of −3.8 cm−1/GPa and strain-free phonon frequency of 656.68 cm−1 were then applied to perform both macroscopic and microscopic stress mappings. For macroscopic stress evaluation, the spatial variation of residual stress was measured across an AlN-on-Si wafer prepared by sputter deposition. A cross-wafer variation in residual stress of ∼150 MPa was observed regardless of the average stress state of the film. Microscopic stress evaluation was performed on AlN piezoelectric micromachined ultrasonic transducers (pMUTs) with submicrometer spatial resolution. These measurements were used to assess the effect of device fabrication on residual stress distribution in an individual pMUT and the effect of residual stress on the resonance frequency. At ∼20 μm directly outside the outer edge of the pMUT electrode, a large lateral spatial variation in residual stress of ∼100 MPa was measured, highlighting the impact of metallization structures on residual stress in the AlN film. [ABSTRACT FROM AUTHOR]

Microelectromechanical systems (MEMS)-based filter with microchannels enables the removal of various microorganisms, including viruses and bacteria, from fluids. Membranes with porous channels can be used as filtration interfaces in MEMS hemofilters or mini-dialyzers. The main problems associated with the filtration process are optimization of membrane geometry and fouling. A nanoporous aluminum oxide membrane was fabricated using an optimized two-step anodization process. Computational strength modeling and analysis of the membrane with specified parameters were performed using the ANSYS structural module. A fuzzy simulation was performed for the numerical analysis of flux through the membrane. The membrane was then incorporated with the prototype for successive filtration. The fluid flux and permeation analysis of the filtration process have been studied. Scanning electron microscope (SEM) micrographs of membranes have been obtained before and after the filtration cycles. The SEM results indicate membrane fouling after multiple cycles, and thus the flux is affected. This type of fabricated membrane and setup are suitable for the separation and purification of various fluids. However, after several filtration cycles, the membrane was degraded. It requires a prolonged chemical cleaning. High-density water has been used for filtration purposes, so this MEMS-based filter can also be used as a mini-dialyzer and hemofilter in various applications for filtration. Such a demonstration also opens up a new strategy for maximizing filtration efficiency and reducing energy costs for the filtration process by using a layered membrane setup. [ABSTRACT FROM AUTHOR]

A friction stir joining technology was used in preparing a performance gradient aluminum alloy sheet through friction stirring. The sheet was treated by solution aging, and the metallographic structure and hardness of the sheet before and after heat treatment were analyzed. Results showed that the sheet with good hardness gradient distribution can be obtained by selecting appropriate process parameters. When the rotation speed of the stirring tool is 300 rpm, the feed speed of the stirring tool is 250 mm/min, the downward pressure of the stirring tool is 6.6 mm, the hardness distribution of the upper and lower surfaces and sections of the specimens with or without heat treatment improves, and the best gradient hardness distribution of the sections is obtained. The grains in the stirred region of the prepared gradient sheet obtained by each parameter are refined to a certain extent, especially after heat treatment. Grain changes are obvious, but the grains grow after heat treatment. The second phase precipitated after heat treatment is evenly distributed, and this is effect improves the hardness of the sheet. The aluminum alloy gradient material prepared in this paper can meet the requirements of the automobile industry and other molding plate performance requirements. It is also found that the friction stir joining technology can better prepare aluminum alloy gradient material, and the fabricated material has fewer defects than the continuous casting technology. [ABSTRACT FROM AUTHOR]

The aim of the research is the analysis of thin-walled aluminum profiles with embossed crush initiator. Samples with square cross-section loaded dynamically were studied until the complete loss of velocity by the tup. The numerical analyses were based on an elastic-plastic material model. The material properties of AA-6063 aluminum were derived from own tests performed on a tensile machine. The analyses were conducted using the numerical method (Abaqus CAE). Using a dynamic testing machine, the obtained numerical data were verified on the basis of models showing the best improvement in crush efficiency indicators. In the experimental study, high-speed camera images were used to identify the forming plastic hinges. Based on the obtained results of experimental and numerical analysis, crush efficiency indicators were determined and compared. It was determined that the use of a passive energy absorber increases the efficiency of the crushing force by around 50%, in addition, the correct location of the crush initiator allows to gain 15%. The results of the study showed that proper placement of the crush initiator decrease Peak Crushing Force (PCF) while increasing mean crushing force (MCF). [ABSTRACT FROM AUTHOR]

The production and study of highly dispersed aluminum-based powders represents one of contemporary science's priority fields. This is primarily driven by the practical necessity to develop new materials, a feat that, in some cases, can only be achieved through the utilization of powdered components. This article presents the results of the mechanochemical treatment method employed to obtain highly reactive aluminum particles. It also includes a comparative analysis of aluminum particles generated through various methods and their respective properties. Furthermore, the application of these highly reactive aluminum particles in energy-intensive materials is discussed. [ABSTRACT FROM AUTHOR]

The native AlOx grown on a thin sputtered aluminum layer can be used as mask for electroplating copper, e.g., for metallizing silicon heterojunction (SHJ) solar cells. Effects that influence the masking quality for selective electroplating are studied herein. Atomic force microscopy characterization in PeakForce mode highlights the presence of some insulation defects in the native AlOx due to local contamination, pinholes, or tunneling currents. A focused ion beam/scanning electron microscopy analysis is further conducted to understand some defects in detail. The AlOx insulation can be improved by adsorbing a self‐assembled monolayer, which is mainly required along the process sequence to adjust the surface wetting of the Al for optimal NaOHaq printing. The mask quality and complete metallization sequence for solar cells are demonstrated on industrial SHJ precursors. Inkjet‐ and FlexTrail‐printing of NaOHaq are shown to be suitable to pattern the Al layer. Promising conversion efficiency comparable to screen‐printing reference is reached on large area. [ABSTRACT FROM AUTHOR]

Combined with the oxidizer anions and fuel cations, molecular perovskite energetic materials show a good potential. In this work, the combustion behavior and mechanism of metal fuel aluminium (Al) with molecular perovskite energetic material (H2dabco)[NH4(ClO4)3] (DAP-4) as a high-energy oxidant was investigated. The DAP-4 based composites with metal fuel Al were designed and fabricated by the different mass ratios. Results showed that DAP-4 exhibits a good oxygen-supplied capacity for enhancing the combustion performance of Al. The maximum combustion heat of DAP-4/Al-3 at the Al/O mass ratio of 38:62 is up to 10,412 J/g in the inert gas, which is higher than those of other ratios and the mixtures of other energetic materials and Al. The evolution of pressure output, pressurization rate, and flame temperature was monitored for DAP-4/Al with different mass ratios. Composites DAP-4/Al/F were characterized by burning rates. The combustion reaction mechanism of metal fuel Al with DAP-4 as a high-energy oxidant was provided. DAP-4 was ignited firstly and released acid and oxidizing gases, which corroded Al2O3 shells on Al particle surfaces and accelerated the combustion reaction with Al to release a lot of energy. This work offered a new idea that molecular perovskite energetic materials have great potential in the high-energy Al-based solid rocket propellants. [ABSTRACT FROM AUTHOR]

The charging modules of Electric vehicles (EVs) always run in a complex and variable state. As the weakness in the reliable operation of charging modules, the accurate lifetime prediction of aluminum electrolytic capacitors (Al-caps) is important for the later maintenance and reliability design. The hotspot temperature calculation method and lifetime model limit the accuracy of aluminum electrolytic capacitors lifetime prediction methods, which cannot meet the increasing requirements for reliability. In order to solve the problems above, this paper has proposed a hotspot temperature calculation method based on the ripple current with frequency characteristics and the cooling conditions on the heat generation and thermal conductivity of the capacitors. Furthermore, the lifetime model under reference voltage has been constructed with 3D surface fitting toolbox, which describes the trends of capacitor lifetime with ambient temperature and hotspot temperature under the constant voltage condition. Considering the variation of voltage, the multiple lifetime model of capacitor is established with a voltage correction coefficient. With the proposed method, it can be realized about the real-time lifetime prediction of capacitors under multiple operating profiles such as ripple current, thermal dissipation conditions, ambient temperature and operating voltage. Finally, the effectiveness of the proposed method is verified with the annual profiles of a 30 kW EV charging module. [ABSTRACT FROM AUTHOR]

Aluminium matrix composites signify a recent advancement in the progression of metal matrix composites, possessing the capability to meet the requisites of various emerging engineering applications. This study aims to concentrate on the mechanical behaviour of AA6082, which was fortified with goat bone ash (GBA). Employing the stir casting technique for casting, aluminium-based metal matrix composites were synthesized, incorporating varied weight percentages (0%, 3%, 6%, and 9%) of goat bone ash as the strengthening element. The introduction of 3% ash particles yielded a 12% augmentation in impact strength, while an even more significant enhancement of 81% in hardness was attributed to the incorporation of 9% ash particles. The material exhibited a tensile strength of 131 MPa without reinforcement, and this value was significantly enhanced by 36.6% upon adding 6% GBA. Subsequently, it was inferred that reinforcement significantly enhanced the physical and mechanical attributes of aluminium metal matrix composites. [ABSTRACT FROM AUTHOR]

Purpose: Pores and shrink holes are unavoidable defects in the die-casting mass production process which may significantly influence the strength, fatigue and fracture behaviour as well as the life span of structures, especially if they are subjected to high static and dynamic loads. Such defects should be considered during the design process or after production, where the defects could be detected with the help of computed tomography (CT) measurements. However, this is usually not done in today's mass production environments. This paper deals with the stress analysis of die-cast structural parts with pores found from CT measurements or that are artificially placed within a structure. Design/methodology/approach: In this paper the authors illustrate two general methodologies to take into account the porosity of die-cast components in the stress analysis. The detailed geometry of a die-cast part including all discontinuities such as pores and shrink holes can be included via STL data provided by CT measurements. The first approach is a combination of the finite element method (FEM) and the finite cell method (FCM), which extends the FEM if the real geometry cuts finite elements. The FCM is only applied in regions with pores. This procedure has the advantage that all simulations with different pore distributions, real or artificial, can be calculated without changing the base finite element mesh. The second approach includes the pore information as STL data into the original CAD model and creates a new adapted finite element mesh for the simulation. Both methods are compared and evaluated for an industrial problem. Findings: The STL data of defects which the authors received from CT measurements could not be directly applied without repairing them. Therefore, for FEM applications an appropriate repair procedure is proposed. The first approach, which combines the FEM with the FCM, the authors have realized within the commercial software tool Abaqus. This combination performs well, which is demonstrated for test examples, and is also applied for a complex industrial project. The developed in-house code still has some limitations which restrict broader application in industry. The second pure FEM-based approach works well without limitations but requires increasing computational effort if many different pore distributions are to be investigated. Originality/value: A new simulation approach which combines the FEM with the FCM has been developed and implemented into the commercial Abaqus FEM software. This approach the authors have applied to simulate a real engineering die-cast structure with pores. This approach could become a preferred way to consider pores in practical applications, where the porosity can be derived either from CT measurements or are artificially adopted for design purposes. The authors have also shown how pores can be considered in the standard FEM analysis as well. [ABSTRACT FROM AUTHOR]

This research paper presents a study and a numerical investigation on the effect of the thickness of the samples on the crack growth as well as the phenomenon of fatigue. As well as the type of alloy used to withstand these physical deformations. Types of samples were designed from aluminum alloys 2024 and 7085 and compared with each other in bearing crack growth as well as the phenomenon of fatigue. The thermal effect was also seen on it by adjusting the temperature value in two cases, 20°C and 40°C. Where an additional processor was added to the Ansys program, which worked on the growth of the crack in a manner consistent with the phenomenon of fatigue. Where a pressure value of 4.8 MPa was applied from one side of the sample and it was fixed from the other side, where a time of 8000 s was taken. Where the results showed that the maximum deformation that was reached was 0.56 mm in the case where the thickness of the sample was 5 mm and the type of metal was aluminum alloy 7085. The value of bone deformation at a thickness of 5 mm is 0.66 mm, which is the highest value of deformation compared to the other cases. Aluminum alloy 7085 has reached a crack growth of 7.5 mm during 2777 cycles. While alloy 2024 has reached the same crack growth during 32784 cycles. The true meaning of the difference in properties between alloys can only be understood by comparing the mechanical properties of different alloys. Comparison of aluminum alloy 6061 with case with 3 mm primitive crack growth and 90 degree crack angle. [ABSTRACT FROM AUTHOR]

Aluminum matrix composites (AMCs) are largely used in defense, maritime, and space applications for their excellent properties. LM5 is used where very high resistance to corrosion from seawater or marine atmospheres is required, for equipment used for the manufacture of foodstuffs, cooking utensils, and chemical plants. Zirconia is preferred over other reinforcements as it shows comparatively great refractory properties, high scratch resistance, and thermal shock resistance. Utilizing the stir casting technique, an attempt was made to produce AMCs of LM5 aluminum alloy strengthened with ZrO2. The weight percentage of ZrO2 was changed to 0%, 3%, 6%, and 9%. The specimens were prepared and tested as per ASTM standards to find the density, micro and macro hardness, impact, tensile, and compressive strength. The micrographs and SEM images confirm the uniform distribution of ZrO2 particles in the aluminum matrix. LM5/9%ZrO2 AMC has the highest density value of 2.83 g/cm3 and LM5/3%ZrO2 has the least porosity of 2.55%. LM5/9% ZrO2 has the highest hardness values of 78 VHN and 72 HRE. LM5/6% ZrO2 AMC has the highest tensile strength of 220 MPa, compressive strength of 296 MPa, and toughness of 12 J. LM5/6% ZrO2 AMCs may be used for many structural applications. [ABSTRACT FROM AUTHOR]

Rapid and accurate analysis of element concentrations in aluminum alloys is crucial due to their widespread use in modern industry. This paper proposes a one-point and multiline calibration fiber-optic laser-ablation spark-induced breakdown spectroscopy (OP-MLC FO-LA-SIBS) for the quantitative analysis of elements in aluminum alloys. The experimental system utilizes a compact fiber laser as the laser-ablation source and spark discharge to enhance the atomic emission. A portable multichannel fiber spectrometer is used to quickly collect spectra in the nongated mode. The concentrations of four elements (Mg, Cr, Cu, and Mn) in four aluminum alloy samples were calculated using the simple and efficient OP-MLC method, which involves taking another sample with a similar matrix as the standard sample. The average relative errors (AREs) for Mg, Cr, Cu, and Mn were 6.38%, 28.09%, 21.92%, and 18.97%, respectively. When the certified concentrations are greater than 0.02 wt.%, the ARE is only 13.04%. The OP-MLC FO-LA-SIBS system is compact, features simple spectra processing, and offers effective measurement, providing a convenient method for rapid and efficient quantitative analysis of elements in aluminum alloys in industrial production. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to compare the radiopacity of calcium silicate cements using a digital imaging method. Methods: Four calcium silicate cements, NeoMTA 2, OrthoMTA, ProRoot MTA, and Biodentine, were used in this study. Disk-shaped samples were prepared from each material and placed on a plexiglass plate. An aluminum step-wedge was placed alongside the samples on a digital sensor and exposed to 70 kVp and 8 mA from 30 cm away for 0.32 s. The greyness values ​​of the tested materials were measured digitally with the system software and compared with those of the step-wedge to determine the equivalent aluminum thickness. Results: The radiopacity values, expressed in equivalent millimetres of aluminum, of the studied materials ProRoot MTA, OrthoMTA, NeoMTA 2, and Biodentine were 4.32 ± 0.17 mm Al, 3.92 ± 0.09 mm Al, 3.83 ± 0.07 mm Al, and 2.29 ± 0.21 mm Al, respectively. Statistically significant differences were found between the mean radiographic density values of the tested materials (p < 0.05). Conclusion: ProRoot MTA was the most radiopaque root canal filling material among the tested materials. All materials, except Biodentine, were found to be compliant with the minimum radiopacity requirements of ISO 6876 and ADA 57 standards. [ABSTRACT FROM AUTHOR]

The article represents a multidisciplinary numerical model for electromagnetic casting of aluminum ingots, as well as the results of its application when casting aluminum ingots diam. 25–30 mm. The numerical model is based on a calculation of the electromagnetic field by solving an additional equation in Fluent combined with the modeling of processes connected with free surface crystallization. The obtained electromagnetic field sources are used in motion and energy equations for solving the magneto-hydrodynamics problem. A solution to the problem of determining the set of technological parameters for ensuring the stable formation of an ingot with the required diameter is provided along with the results of emergency mode modeling. In addition, the article presents the results of applying the established emergency modes at the laboratory casting unit with the electromagnetic mold for the production of ingots using Nikolin and Altsimak experimental alloys as part of ElmaCast® technology. [ABSTRACT FROM AUTHOR]

Laser-induced breakdown spectroscopy (LIBS) technique is employed for quantitative analysis of aluminum samples by different classical machine learning approaches. A Q-switch Nd:YAG laser at a fundamental harmonic of 1064 nm is utilized for the creation of LIBS plasma in order to predict constituent concentrations of the aluminum standard alloys. In the current research, concentration prediction is performed by linear approaches of support vector regression (SVR), multiple linear regression (MLR), principal component analysis (PCA) integrated with MLR (PCA–MLR), and SVR (PCA–SVR), as well as nonlinear algorithms of artificial neural network (ANN), kernelized support vector regression (KSVR), and the integration of traditional principal component analysis with KSVR (PCA–KSVR), and ANN (PCA–ANN). Furthermore, dimension reduction is applied to various methodologies by the PCA algorithm in order to improve the quantitative analysis. The results indicated that the combination of PCA with the KSVR algorithm model had the best efficiency in predicting most of the elements among other classical machine learning algorithms. [ABSTRACT FROM AUTHOR]

Pinus massoniana is an important timber tree species in southern China, and acid aluminum stress seriously endangers its growth. This study focuses on physiology, gene regulation and root exudates. Aluminum stress increased the activity of malondialdehyde (MDA), proline (PRO), peroxidase (POD), soluble proteins (SP), soluble sugars (SS) and superoxide dismutase (SOD) in P. massoniana seedlings, and led to changes in growth. We identified hub genes (UCHL3, TCP1, SEC27, GluRS and ACTF) responding to aluminum stress of low concentration and hub genes (RGP, MPT, RPL24, RPL7A and EC3.2.1.58) responding to aluminum stress of high concentration. Aluminum stress mainly affected phenylpropanoid biosynthesis and flavonoid biosynthesis, and it may alleviate aluminum toxicity by inducing the upregulation of genes such as CHS, COMT, DFR and LAR to enhance root exudation of catechin. These results lay the foundation for in-depth studying the molecular mechanism of P. massoniana aluminum stress. [ABSTRACT FROM AUTHOR]

Dynamic spatial distribution and evolution of three-dimensional (3D) voids/cracks in engineering materials are crucial information to predict fatigue damage and residual life. A method of fatigue damage analysis was proposed and used to estimate low-cycle fatigue damage. First, multi-stage fatigue damage defects were measured based on x-ray computed tomography (XCT). 3D voids/cracks were reconstructed and analyzed by VG Studio and Diego algorithm. Then, 3D voids/cracks were transferred into finite element model along with material domain for numerical analysis. Thirdly, the damage transformation process was achieved by means of 3D finite element analysis. And the numerical and experimental results were compared. The estimated damage variables in terms of effective elastic modulus were in agreement with experimental results. It is indicated that the proposed numerical prediction method is valid for damage evolution in low-cycle fatigue. [ABSTRACT FROM AUTHOR]

In the present work, the feasibility of using aluminum pipes for irrigation in agricultural fields for reuse on a farm as underground canalization is analyzed. Due to the need to have a group of grain mills, it is necessary to build a new electrical branch in the installation, and due to limitations it is essential that the new pipeline be buried. Therefore, the finite element method is used to analyze the behavior of three conductors within the aluminum duct. Taking into account the effects of the magnetic field in the aluminum material and the eddy currents that are formed, which increase the losses in the energy distribution. The analysis of the behavior of electrical losses within the pipeline, it was studied how the proximity of the conductors to the pipe wall affects and the changing the distribution of the conductors inside the pipe was also verified. [ABSTRACT FROM AUTHOR]