Increasing Aluminum Content Research Articles

Ultrasonic elliptical vibration micro-cutting mechanism of CoCrFeNiAlX short fiber reinforced aluminum-based composite

This study explores the precision micro-machining of CoCrFeNiAlX short fiber-reinforced 7A09 aluminum matrix composites, focusing on the interplay between machining parameters and composite properties. The investigation scrutinizes the influence of vibrational amplitude, oscillation frequency, penetration depth, fiber orientation, and aluminum concentration on machining dynamics. Findings reveal that enhancing the X-axis vibrational amplitude to 80 μm is associated with a decrease in machining force, which then rises after reaching a threshold. In contrast, maintaining the Y-axis amplitude below 90 μm significantly increases the machining force. Higher amplitudes and frequencies were observed to reduce machining forces by up to 57% at an ultrasonic frequency of 15 kHz. Employing ultrasonically assisted vibration cutting (UEVC) culminated in a substantial 72% decrease in machining forces when fibers were optimally oriented at 45°. The study also identifies a direct correlation between the cutting temperature and both the vibrational amplitude and penetration depth, with the Y-axis amplitude having a more significant impact, causing a 55% variation in temperature. An increase in frequency initially lowers the cutting temperature, with the lowest temperature of 92 °C achieved at 5 kHz, while the peak temperature occurs at a machining depth of 60 μm. Temperature profiles indicate an initial rise with increased fiber orientation, followed by a decline. A slight increase in aluminum concentration marginally raises the cutting temperature. Furthermore, UEVC is found to produce a parabolic residual stress distribution, where amplitude and penetration depth determine the peak stress levels, and higher frequencies contribute to stress reduction. Fiber orientation also affects residual stress, with proper alignment reducing compressive stress and misalignment increasing it. The lowest point of residual compressive stress is detected in the Al0.6 fiber composite, while the peak is observed in the Al1 composites.

Developing Deep Ultraviolet Laser Diode: Design and Improvement of Al0.62Ga0.38N/Al0.68Ga0.32N Quantum Wells on AlN Substrates for 266 nm DUV Emission

A deep ultraviolet (DUV) laser diode is a compact and efficient semiconductor device that emits laser light in the deep ultraviolet range. Its unique properties make it suitable for a wide range of applications in fields such as manufacturing, research, and healthcare. In this research we propose two Al-graded Electron Blocking Layer (EBL) and quantum barriers (QBs) to improve the performance of AlGaN-based Deep UV-LDs. The electrical properties and optical properties of three structures containing conventional EBL, composition graded increased EBL, and liner graded increased of EBL and QBs were numerically investigated. It was found that the structure-C with linear graded increased EBL and QBs significantly improved the Optical Confinement Factor (OCF) 21%, gain 1600 cm-1, emission power 0.060 W, raised the carrier concentration in the MQWs region, enhanced the stimulated recombination rate and reduced the carrier leakage, of the laser diode (LDs). But at a 100-mA injection current, the threshold current and voltage were reduced to 43 mA and 5.00 V, valance barrier height 270 meV respectively. In compare to the conventional structure, introducing a graded design for both EBL and Quantum Barriers (QBs) with increased aluminum content significantly enhanced the performance of the laser diode (LD). This improvement is essential for advancing Deep Ultraviolet Laser Diodes (DUV-LD) technology.

Studying of cadmium oxide/ Aluminium films for optoelectronics: structural, optical and electrical characteristics

In the results of this research, thin films of CdO-Al were produced using the spray pyrolysis (SP) technique. The primary aim was to explore how varying concentrations of aluminum (Al) influence the physical properties of the films. The X-ray diffraction (XRD) analysis confirmed the presence of a cubic crystal structure in the pure CdO films. Additionally, it revealed that the introduction of increased Al doping led to lattice shrinkage and a reduction in lattice parameters. Elevated levels of aluminum (Al) content were correlated with a decrease in crystallite size and an augmentation in lattice strain, as indicated by both scanning electron microscopy (SEM) and X-ray diffraction (XRD) data. Additionally, an X-ray photoelectron spectroscopy (XPS) examination revealed the presence of Al3+ ions within the films. The optical energy gap of CdO-Al films exhibited a slight increase, reaching up to 3% aluminum doping. The analysis of the refractive index dispersion and non-linear refractive index revealed a decreasing trend up to 3% aluminum content, with subsequent fluctuations at higher concentrations. The measurements of sheet resistance demonstrated a noticeable decrease with an increase in aluminum content, specifically up to 3%.

Relationship between viscosity, foaming, and structure of CaO–SiO2–Al2O3–MgO–FeO slag with the addition of SiO2 and Al2O3

Optimizing the foaming characteristics of slag in electric arc furnaces (EAF) presents a challenging task, affecting electrode heating efficiency and increasing smelting cost. This study explores the impact of adding silicon dioxide (15–35 wt%) and a small quantity of alumina (5–10 wt%) on the viscosity and foaming properties of CaO–SiO2–Al2O3–MgO–FeO slag. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were employed to investigate structural changes in the slag melt. The findings reveal that higher levels of silica or a slight increase in alumina content enhance slag polymerization and foaming efficiency. Specifically, a 10 wt% alumina content, in contrast to 5 wt%, leads to high silica content, leading to faster polymerization but relatively lower viscosity. Structural analysis confirms that increasing alumina content, particularly when silica content is high, results in a less stable Al–O–Si structure, causing a shift from Q0 and Q1 units to Q2 and Q3 units, which ultimately reduces viscosity. When the alumina content remains at 5 wt% and silica content increases from 15 wt% to 35 wt%, foaming efficiency improves from 13.06 cm min to 94.97 cm min, a remarkable 627% rise. Moreover, when silica content is 30 wt% and alumina is slightly increased by 5 wt%, there is a notable enhancement in foaming efficiency, rising from 47.11 cm min to 89.16 cm min, while the effect on viscosity is not prominent.

Application of Metal Oxide in Litho-Vanadium Glasses Containing Non-Magnetic Metal Ions: Physical and Optical Properties Analysis

Sodium-modified litho-vanadium glasses containing non-magnetic Aluminium ions of composition 50Li2CO3 - (30-X) Na2 CO3- 20V2O5 -xAl2O3 (30 ≤ x ≥ 5) (LNVA) glasses were prepared by melt quenching technique. The density of the glass samples was measured and found to increase with the Aluminium content of the glass matrix. The measured values of refractive index and polaron radius of the glass network show opposite behaviour with an increase of Aluminium content. Through band gap energy and refractive index, Oxide ion polarizability and electronic polarizability were determined by using the Lorentz-Lorenz equation. The value of Oxide ion polarizability and electronic polarizability is found to be decreased with decreasing band gap energy and increasing refractive index. The value of optical basicity was measured using electronic polarizability and is found to be decreased with decreasing inter-nuclear distance. The band gap energy values of the glass network were found to decrease from 3.241 to 2.134 eV. The metallisation criterion of the glass material was calculated and found to decrease with Aluminium content.

Pre and post-operative serum levels of titanium cobalt and aluminium after implant placement.

The preoperative serum levels and postoperative serum levels of titanium, cobalt and aluminium from dental implants in order to assess the release of these ions and to assess any risk of toxicity from these ions after dental implant placement is of interest to dentists. It was observed that there was very slight increase in serum concentration of titanium, cobalt and aluminium after 12 months of placement of implants as compared to before placement of implants. However the increase was non-significant statistically. Our study concluded that the use of dental implants does not pose any risk of toxicity of metal ions like titanium, aluminium and cobalt because of very slight non-significant increase in serum levels of these ions 12 months after implant placement.

Structural, optical and electrical properties of Al-doped CdO nanoparticles by solid state reaction

In the present study, aluminium doped cadmium oxide (Cd1-xAlxO) nanoparticles at (x = 0.00, 0.03, 0.05 & 0.07) concentrations were prepared using solid-state reaction and synthesized nanoparticles were subjected to different characterisations such as X-ray diffractometer (XRD), UV–Vis-Spectrophotometer (UV–Vis–NIR), field emission scanning electron microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and I–V measurements. The X-ray diffraction patterns confirm the polycrystalline nature of the Cd1-xAlxO nanoparticles with cubic structure. From the XRD patterns, the crystallite size and other structural parameters were calculated. The diffuse reflectance spectra were used to calculate the optical bandgap of the Cd1-xAlxO nanoparticles and it increased with increase of aluminium (Al) concentration (2.00 eV–2.04 eV). The FT-IR spectra confirm the Cd–O vibrational bands in the Cd1-xAlxO nanoparticles.The morphological studies revealed the spherical shape of the synthesized nanoparticles. The XPS spectra confirm the presence of aluminium (Al), cadmium (Cd) and oxygen (O) in the desired ratios. The current versus voltage characteristics of the Cd1-xAlxO nanoparticles were studied using Keysight source metre.

Cadmium Sorption on Alumina Nanoparticles and Mixtures of Alumina and Smectite: An Experimental and Modelling Study

Cadmium (Cd) is one of the most toxic transition metals for living organisms. Thus, effective measures to remediate Cd from water and soils need to be developed. Cd immobilization by alumina and mixtures of alumina and smectite have been analyzed experimentally and theoretically by sorption experiments and sorption modelling, respectively. Removal of aqueous Cd was dependent on pH and Cd concentration, being maximal for pH > 7.5. A two-site non-electrostatic sorption model for Cd sorption on alumina was developed and it successfully reproduced the experimental Cd immobilization on alumina. Cd sorption on mixtures of alumina and smectite were depending on pH, ionic strength, and alumina content in the mixture. Cd removal in mixtures increased with alumina content at high pH and ionic strength values. However, Cd sorption decreased with increasing alumina content under acidic conditions and low ionic strength. This effect was the result of alumina dissolution and the release of Al3+ into the suspension at low pH values. Modelling of Cd sorption on mixtures of alumina and smectite was performed by considering the individual Cd sorption models for alumina and smectite. It could be shown that the contributions of the individual sorption models were additive in the model for the mixtures when the competition of Al3+ with Cd2+ for cation exchange sites in smectite was included.

Investigation of Element Migration from Aluminum Cooking Pots Using ICP-MS

The present study examined the migration of elements from aluminum cooking pots to foods after the cooking process. This study investigated the impact of pot quality (manufacturer), pot type (traditional or pressure cooker), water supply (tap water/mineral water), food acidity, salt, spices, temperature, and cooking time on the migration of elements into cooked food. The cooking experiments were conducted to simulate the actual cooking conditions. Standard food simulant B, with 3% (w/v) acetic acid, was used in subsequent cooking trials to confirm the results. Three methods were employed to analyze the elements in the food: ICP-MS, EDS-SEM, and XPS. The cooking pots used in this investigation were examined using a Spectromaxx metal analyzer to characterize their chemical composition. The concentration of aluminum in cooked food samples increased significantly when using an aluminum pressure cooker. Food acidity, cooking duration, and the type of aluminum pot (traditional/pressure cookers) all affected the concentration of elements that migrated into the food. The aluminum level increased from 80.17 to 133.7 µg/g when tomato sauce was added to the food. Increasing the heating time resulted in an increased aluminum content (157.9 µg/g) in the cooked food. Aluminum pressure cookers exhibited the highest amount of aluminum migration into the food. Foods cooked in a pressure cooker made by manufacturer (3) contained the highest aluminum content (252.7 µg/g), which increased the risk of exceeding the daily intake limit of aluminum. The prepared food samples under all conditions showed a safe health profile for daily intake of all elements (Fe, As, Cd, and Pb), except for Al, which exceeded the daily intake limit when using pressure cookers for extended cooking times. The results of element migration into food simulants were consistent with those of food samples. The results confirmed that SEM-EDS and XPS techniques are not suitable for quantifying the elements that migrated into food samples due to their detection limits.

Temperature dependence of Young’s modulus and the occurrence of an elastic anomaly in porous alumina-mullite composites prepared by starch consolidation casting

The temperature dependence of Young’s modulus has been measured by impulse excitation up to 1400 °C (heating and cooling) for alumina-mullite composites with 40–60 wt% alumina prepared by starch consolidation casting, after firing at 1570 °C, resulting in materials with high porosities (43–57 %). Using previously determined temperature master curves, both analytical predictions and numerical computations on computer-generated microstructures are compared with experimental data, resulting in excellent agreement for the alumina-mullite composites. Apart from the overall decrease of Young’s modulus during heating, an elastic anomaly starting at around 950 °C and cumulating at around 1050 °C is observed in all cases during heating (but not during cooling), and is shown to be stronger with increasing alumina content and porosity. The results are discussed in terms of a “glass phase hypothesis” and a “phase transition hypothesis”, although neither of them provides a satisfactory explanation of the observed phenomenon.

Influence of iron substitution on structural, magnetic, and magnetocaloric properties of Tb2Fe17−xAlx compounds synthesized by arc melting

In the present work, the structure and magnetic and magnetocaloric properties of the Tb2Fe17−xAlx compounds with x=0,0.25,0.5,0.75, and 1 were studied. These compounds were synthesized by arc furnace without subsequent annealing. Their crystal structure is a Th2Ni17 hexagonal structure with a P63/mmc space group. The Rietveld refinement of the X-ray diffractograms allowed for determining the structural parameter variations with different amounts of aluminum. Lattice parameters and the unit cell volume increase with aluminum amounts while the c/a ratio remains nearly constant. The Tb2Fe17−xAlx compounds exhibit a second-order magnetic phase transition from a ferromagnetic state to a paramagnetic state. The Curie temperature (TC) increases with the aluminum content, the observed effect is due to the magnetovolumic effect. The saturation magnetization (MS) decreases with the increase of Al content. Magnetic entropy and relative cooling power (RCP) decrease as the aluminum content increases. Tb2Fe17−xAlx compounds have a moderate magnetocaloric effect and a tunable operating temperature interval.

Influence of seasonality on the physical-chemical properties of water for human consumption by residents of floating villages in the interior of the Amazon

Abstract The aim of this study was to evaluate the physicochemical properties of the water consumed by residents of floating houses and the influence of the hydrological cycles of flood and drought on these parameters. The sample consisted of 44 floating domestic units per hydrological cycle, located on the edges of the cities of Codajás, Coari and Tefé. Sociodemographic data and data related to water consumption and storage habits were collected using a semi-structured questionnaire. Water samples were collected and analyzed in accordance with the Standard Methods for the Examination of Water and Wastewater. Data were analyzed in the dry and flood hydrological phases and compared to the maximum values allowed by Ordinance GM/MS No. 888/2021. The results showed that the nitrite, manganese and free residual chlorine parameters were not in accordance with the legislation. Manganese (p = .035) and aluminum (p < .001) showed significant differences between the hydrological phases. The considerable increase in aluminum content during the flood period, even though it was within the limits of the ordinance, was also highlighted. Accordingly, even with periodic control by the supply companies, it is important to monitor the water at the point of consumption of the population.

Effect of nitrogen pressure on the fabrication of AlCrFeCoNiCu0.5 high entropy nitride thin films via cathodic arc deposition

In the past two decades, high entropy alloy (HEA) coatings have attracted great attention due to their superior mechanical properties, outstanding corrosion and oxidation resistance, and exceptionally high thermal stability. In comparison to HEA thin films, high entropy nitrides (HENs) exhibit higher mechanical strength and chemical inertness. In this work, AlCrFeCoNiCu0.5 HEA and HEN thin films were fabricated using a filtered cathodic arc. By regulating the deposition pressure from 0.0005 Pa (HEA thin film) to 0.05 Pa, the nitrogen concentration in each thin film was precisely controlled to tune the mechanical properties. Scanning transmission electron microscopy-energy dispersive spectroscopy revealed that the nitrogen concentration of the films was up to 21.2 at. % at the pressure of 0.05 Pa. The reduced effect of preferential sputtering increased aluminum concentration from 8.3 ± 1.5 to 12.9 ± 2.2 at. % as pressure increased up to 0.05 Pa. X-ray photoelectron spectroscopy further confirmed the formation of AlN and CrN at pressures of 0.01–0.05 Pa. The highest hardness and elastic modulus of the HEN film were 12.4 ± 0.6 and 347.3 ± 17.7 GPa, respectively, which were 84.8% and 131.4% higher than those of the HEA thin film.

Study of 100V GaN power devices in dynamic condition and GaN RF device performances in sub-6GHz frequencies

AlGaN/GaN devices for both power and RF applications have been investigated in this work. In particular, regarding power applications, 100 V p-GaN gate transistors have been analysed both in DC and in dynamic conditions with specific attention to the high temperature behaviour.As a first step, the high temperature behaviour of the on-resistance (RON) of a reference process (STD process) has been investigated. The role of the different resistive components of the transistor has been analysed by evaluating how their relative weight changes with the temperature increase. Then, two different p-GaN process variations (process A and process B) have been proposed and compared to the STD process to show their improvement in terms of a limited RON increase at 150 °C, highlighting the relevance of an improved p-GaN gate processing.Secondly, the temperature effect on the RON-degradation induced by off-state drain voltage stress has been investigated in process B-like devices. The impact of temperature on the time required to reach a steady state degradation has been addressed, enabling the comparison of the RON degradation (RON/ RON0) at equilibrium. Tests performed on several samples have demonstrated the invariance of the RON/ RON0 ratio in the 25 °C to 150 °C range, suggesting the possibility to reduce the measurements required for dynamic-RON evaluation at different T.Finally, RF devices (featuring Schottky metal gate) have been characterized in terms of DC/RF performances and long-term reliability (through HTRB tests). Different trials with increasing aluminium content of the AlGaN barrier have been compared, showing the correlation with the maximum saturation current and the output power. Moreover, the trade-off with reliability specifications has been put in evidence.

Evaluation of a continuous flow electrocoagulation reactor for turbidity removal from surface water

The objective of this research was to evaluate the performance of a continuous electrocoagulation (EC) reactor for treating surface waters with high turbidity levels. The reactor design consisted of 20 interconnected channels arranged in series, resulting in an effective treatment volume of 8.7 L. The results showed that increasing the flow rate, voltage, and operating time improved turbidity removal. However, high initial turbidity levels had a negative impact on removal. In the continuous EC test, synthetic water containing kaolin with an initial turbidity of 150 NTU was treated at a flow rate of 300 mL.min−1 and a voltage of 30 V for 30 min. This configuration achieved a turbidity removal efficiency of 97.26%. However, the treated water exhibited an increase in aluminum concentration from 5.881 mg.L−1 to 6.871 mg.L−1, exceeding the limits set by the World Health Organization (WHO). This unfavorable consequence was attributed to the release of aluminum metal ions during the inherent electrolytic oxidation process in EC. Furthermore, an economic analysis showed that the operating costs for continuous operation amounted to 0.087 USD.m−3, demonstrating the economic viability of implementing the continuous EC reactor on a larger scale.

High adsorption capacity of ammonia nitrogen on hexagonal porous aluminosilicate derived from solid-waste bagasse bottom ash

This study investigates the use of a hexagonal-porous aluminosilicate (HAS) adsorbent derived from bagasse bottom ash (BBA), an agricultural solid waste, for the adsorption of ammonia nitrogen (NH3–N)—a key water pollutant from agricultural and farming activities. Sodium silicate derived from BBA via the alkaline fusion method was employed, resulting in energy savings due to a synthesis temperature 1.53 times lower than that of commercial sodium silicate synthesis. The sol-gel method was utilized to successfully synthesize HAS featuring a high surface area and porosity using the sodium silicate prepared from BBA. However, an increase in aluminum content resulted in a decrease in surface area and hexagonal porosity. In performance tests, the HAS(5) adsorbent exhibited the most efficient NH3–N removal, outperforming other adsorbents by 4.54–25.19 times across all initial concentrations. This enhanced efficiency can be attributed to its numerous acidic surface sites, enabling the bonding of NH3–N molecules through monolayer adsorption on the HAS surface.

Polycrystalline Transparent Al-Doped ZnO Thin Films for Photosensitivity and Optoelectronic Applications.

Thin nanocrystalline transparent Al-doped ZnO (1-10 at.% Al) films were synthesized by solid-phase pyrolysis at 700 °C. Synthesized Al-doped ZnO films were investigated by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, TEM). All obtained materials were crystallized into the wurtzite structure, which was confirmed by XRD. The material crystallinity decreases with the introduction of aluminum. SEM and TEM showed that the films are continuous and have a uniform distribution of nanoparticles with an average size of 15-20 nm. TEM confirmed the production of Al-doped ZnO films. The transmittance of Al-doped ZnO films in the range of 400-1000 nm is more than 94%. The introduction of 1% Al into ZnO leads to a narrowing of the band gap compared to ZnO to a minimum value of 3.26 eV and a sharp decrease in the response time to the radiation exposure with a wavelength of 400 nm. An increase in aluminum concentration leads to a slight increase in the band gap, which is associated with the Burstein-Moss effect. The minimum response time (8 s) was shown for film containing 10% Al, which is explained by the shortest average lifetime of charge carriers (4 s).

Beneficiation of andalusite ore by shaking table process using design of experiments methodology

ABSTRACT Andalusite is an alumina-silicate raw material, principally used in the manufacture of heat-resistant refractory products. In the present research, the andalusite mineral was successfully recovered from andalusite ore using a shaking table coupled with magnetic separation. The effects from shaking table parameters, that is deck tilt angle and water flow rate, on the alumina grade and andalusite mineral recovery were investigated using a design of the experiment (DOE), X-ray fluorescence (XRF), and X-ray diffraction (XRD). The results revealed that the deck tilt angle was the main influencing factor on the processing of andalusite ore. The application of a desirability function on the shaking table showed the increase of alumina content from 20.73 to 38.46 wt.% with a recovery rate of 80%. The recovered andalusite's grade fits the requirements for refractory product manufacturing.

Study of the Influence of Doping on the Structural, Optical and Electrical Properties of zinc oxide thin Films Produced by by Spray Pyrolysis for Solar Cell Applications

In the present study, the effect of Al doping with 0.5 % Al (AZO-0.50), 1 % Al (AZO-1.00), and 1.5 % Al (AZO-1.50) have been successfully synthesized by Spray Pyrolysis method. The structural, optical and electrical properties of the obtained films was studied. The obtained films are characterized by different techniques such as X-ray diffraction (XRD), UV-visible and electrical Hall Effect measurements. The X-ray diffraction confirmed that the Al doping did not change the ZnO Hexagonal Wurtzite structure. Spectroscopic measurements in the UV-VIS-IR wavelength range were found to give good average transmittance values of about 73%, with a high transmittance of 75% with 0.5% Al doping. The optical gap value increases in the range of 3.23 to 3.26 eV with increasing aluminium content. The electrical analysis shows that the conductivity improved with doping compared to the pure ZnO film

Непружність та демпфуюча здатність магнію і сплавів Mg—Al в умовах циклічного високоамплітудного навантаження

For Mg—Al alloys with magnesium content from 0 to 9%, measurements of anelastic deformation, damping capacity, and twinning start stresses were carried out. The method of cyclic loading under tension for a wide range of oscillations amplitudes with precision fixation of displacement was used. A method for determination of the start twinning deformation point σ0,002tw under conditions of cyclic loading is proposed, This stress characterizes the beginning of the inverse twinning stage, when the anelastic strain is 2∙10-5. Characteristics of σ0,002tw for technical magnesium and its alloys with aluminum in a wide range of plastic deformation are determined. An insignificant linear increase of σ0,002tw with increasing deformation was established for all Mg—Al alloys. The start twinning deformation point increases with increasing aluminum concentration. For low-alloy alloys with a solid-solution strengthening mechanism, the stress at the beginning of twinning increases insignificantly. For highly alloyed alloys, a significant increase of σ0,002tw stress is observed. It is established that repeated loading within the hysteresis loop to stresses. which is less than the maximum and is not accompanied by additional plastic deformation. If the level of applied stresses during repeated loading reaches the maximum value, the amount of plastic deformation after unloading increases. The addition in εpl gradually decreases with the rise of cycles number. The dependences of inelastic deformation and dissipated energy on the previous deformation degree for all investigated magnesium alloys demonstrate an extreme character. The growth of these characteristics is observed only in the initial part of the load to the residual deformation of 1—2%. With a further increase in deformation, the tendency to anelasticity and the damping capacity decrease. For the dependences dissipatson energy vs amplitude of loob stress, the maximum of dissipation energy is observed under the condition when the stress reaches a critical value, which corresponds to the beginning of prismatic or pyramidal sliding. Keywords: Mg—Al alloys, quasi-static cyclic loading, hysteresis loops, dissipation energy, damping capacity, elasticity, anelasticity, twinning start point.