Aluminum Deposition Research Articles

The Mechanism of Aluminum Deposition and Dendrite Growth on a Copper Substrate in Anode-Free Aluminum Batteries.

Given the critical demand for batteries with a high energy density and the global scarcity of lithium, anode-free aluminum batteries (AFABs) have attracted significant attention. AFABs utilize collectors instead of traditional anode metal foils, eliminating the need for anode materials and significantly enhancing the energy density of the batteries. However, the proliferation of aluminum dendrites might cause safety risks and reduce Coulombic efficiency, possibly impeding commercialization. This study employs molecular dynamics (MD) simulations to explore the deposition mechanisms of aluminum (Al) on copper (Cu) collectors and the dynamics of aluminum dendrite growth under nonhomogeneous deposition conditions. The results indicate that the surface properties of the Cu substrate significantly affect aluminum deposition, leading to more homogeneous and amorphous deposition on Cu(110) surfaces. However, the FCC structure of Al atoms on the Cu(111) surfaces exhibited the largest number. Strategically increasing the temperature and pressure can effectively prevent the formation of aluminum dendrites. The results are helpful for enhancing the battery cycle stability and the application of novel AFABs.

ENHANCING SURFACE CHARACTERISTICS OF AA2024-T3 AIRCRAFT ALLOY THROUGH SYNERGISTIC ANODIZATION AND CERIUM CONVERSION COATING. PART I: PERFORMANCE IN MODEL CORROSIVE MEDIUM

The present study is devoted to the monitoring of the performance of AA2024-T3 specimens, after the formation of Anodic Aluminum Oxide (AAO) layer and/or deposition of a Ceruim Conversion Coating (CeCC), obtained at 20°C and 50°C, respectively. Although both methods are well described in the literature, there is no sufficient information regarding the effect of their combination on their behaviour in corrosive media. The performance of the respective specimens was elucidated after 24 h of exposure to 3.5 % NaCl model corrosive medium (MCM) by means of Electrochemical Impedance Spectroscopy (EIS) and acquisition of Potentiodynamic Scanning (PDS) curves. Since the combined AAO/CeCC coating primers revealed superior barrier properties, the respective specimens weresubjected to long-term corrosion tests of up to 672 h of exposure to the MCM to evaluate their durability. The results revealed the synergistic effect of the combination of the surface treatment procedures on effective corrosion mitigation.

A Critical review on the performance and microstructural characteristics of materials fabricated through friction stir additive methods and deposition techniques

This review examines the distinctions between metallic alloys fabricated using friction stir techniques in additive manufacturing, focusing on friction stir additive manufacturing (FSAM) and additive friction stir deposition (AFSD) of aluminium, magnesium, and titanium alloys. The analysis emphasizes the microstructural characteristics and mechanical properties of these alloys. FSAM is noted for its ability to produce refined equiaxed grains, contributing to enhanced mechanical strength and structural integrity. In contrast, AFSD is characterized by its ability to achieve significant microstructural refinement, leading to improved hardness and corrosion resistance. However, challenges such as resolution limitations, mechanical stability issues in high-aspect-ratio structures, and the need for optimized post-processing persist. The study underscores the potential of FSAM and AFSD to advance additive manufacturing by addressing these challenges and optimizing process parameters for a wide range of engineering applications.

Wire arc additive manufacturing of stainless steel/aluminum bi-metal using roll-bonded transition joint

Wire arc additive manufacturing was employed to produce an AISI316L stainless steel/AA5183 aluminum bi-metal wall using a bi-layer steel/aluminum transition joint fabricated by roll bonding. The transition joint was utilized to minimize the contact between molten aluminum and steel. The study explored the effect of three heat-input levels used for aluminum deposition on the microstructure and mechanical performance of the steel/aluminum interface in the wall. At the minimum heat-input, no defects or Al-Fe intermetallic compounds were observed at the interface, resulting in the highest bi-metal wall fracture strength (∼42 MPa) due to the absence of brittle intermetallic compounds.

AFSD-Physics: Exploring the governing equations of temperature evolution during additive friction stir deposition by a human-AI teaming approach

This paper presents a modeling effort to explore the underlying physics of temperature evolution during additive friction stir deposition (AFSD) by a human-AI teaming approach. AFSD is an emerging solid-state additive manufacturing technology that deposits materials without melting. However, both process modeling and modeling of the AFSD tool are at an early stage. In this paper, a human-AI teaming approach is proposed to combine models based on first principles with AI. The resulting human-informed machine learning method, denoted as AFSD-Physics, can effectively learn the governing equations of temperature evolution at the tool and the build from in-process measurements. Experiments are designed and conducted to collect in-process measurements for the deposition of aluminum 7075 with a total of 30 layers. The acquired governing equations are physically interpretable models with low computational cost and high accuracy. Model predictions show good agreement with the measurements. Experimental validation with new process parameters demonstrates the model’s generalizability and potential for use in tool temperature control and process optimization.

Floating potential probes for process control during reactive magnetron sputtering

Long term deposition of aluminum oxide by reactive magnetron sputtering results in a drift of the discharge voltage. A similar drift of the floating potential is observed. The latter observation is further investigated and it is shown that the change of the floating potential can be linked to a change of the electric properties of the vacuum chamber walls. Optimization of the floating potential probe is performed to use the difference between the discharge voltage and the floating potential as a parameter for process control. The best results were obtained with a planar probe sufficiently far positioned opposite to the magnetron, and close enough to the chamber wall facing the magnetron. This choice can be understood in terms of the ability of the probe to sense the discharge while being protected from deposition. The usage of the aforementioned difference to control the process is demonstrated with the measurement of process curves, more specifically IV-characteristics and hysteresis experiments. The shown reproducibility of these measurements opens a pathway for more precise quantification of reactive sputter deposition simulations and enhanced process control.

Effect of Deposition Conditions on Properties of Aluminum Deposit Obtained from Aluminum Chloride-Acetamide Melts

Although aluminum (Al) electrodeposition using nonaqueous solutions has been widely studied, the process cost is not low. Because aluminum chloride (AlCl3)-acetamide (AcA) deep eutectic solvent (DES) takes low cost and produce better Al deposits than the AlCl3-based ionic liquid in dry air process costs may be reduced. However, the effect of the Al electrodeposition conditions using the AlCl3-AcA DES has not been clear. We investigated the effect of the operating temperature on the properties of Al electrodeposition using the AlCl3-AcA melt. At the operating temperate of 50 °C, the grain shape was fine-scale, similar to the surface morphology of the deposit in the AlCl3-urea melt.In contrast, at the operating temperature of 90 °C, the grain shape changed to fine grains. Based on these results, it was revealed that the grain shape and the preferential orientation of the Al deposit would be affected by operating temperature.

The impact of aluminum oxide deposition on the high-temperature resistance of silica aerogels

The impact of aluminum oxide deposition on the high-temperature resistance of silica aerogels

Microstructural evolution and interfaces in cold sprayed hybrid aluminum alloy powders of different hardness

The development of thick cold sprayed deposits of hard amorphous/nanocrystalline Aluminum High Entropy Alloys (Al HEA) is limited by their poor plastic deformability. To address this, Al HEA powder (Al90.05Ni4.3Y4.4Co0.9Sc0.35 (at. %)) is blended with soft Al 6061 in a 1:1 wt% ratio and cold sprayed. The microstructure of the composite deposits reveals that while Al HEA splats undergo limited deformation, Al 6061 splats deform extensively. Extreme deformation of Al 6061 captures the hard Al HEA particles, resulting in a composite deposit of 5 mm thickness, compared to 0.2 mm for pure Al HEA. Within the composite, Al HEA particles deform through shear band propagation and viscous flow, whereas Al 6061 splats deform via dislocation slip motion. These deformation mechanisms induce interface nanocrystallization, leading to a 123 % increase in lattice strain, a 67 % reduction in crystallite size, and an 800 % increase in dislocation density compared to the initial feedstock. This microstructural evolution, combined with the presence of hard Al HEA regions, results in a mean hardness of 2.56 GPa and an elastic modulus of 76 GPa. These values represent a 47 % and 6 % improvement over conventional polycrystalline cold-sprayed aluminum deposits. Thus, this study provides insights into the microstructural and interface evolution and its effect on indentation characteristics for making high-strength Al HEA deposits.

The rare-earth elements recovered from the leachate of discarded phosphor by electrodeposition

ABSTRACT Recovering rare-earth elements (REEs) from discarded phosphors is an important solution to alleviate the current shortage of rare-earth resources, the aluminum element in discarded phosphors will badly affect the purity and recovery of rare-earth elements. An electrodeposition method for recovering the rare earth from the discarded phosphoric leachate was proposed to avoid the effecting of aluminum elements. The results show that the purity of the rare-earth oxides recovered reached 99.13% and the recovery rate of rare-earth elements reached 98.89% by adopting the optimal electrodeposition process with the help of the complexing agent glycine. Research has found that adding the complexing agent glycine can help rare-earth hydroxides precipitate at the cathode and inhibit aluminum ion precipitation by changing the aluminum deposition potential. Moreover, it was also found that the generation of OH- ions by reduction of NO3- in acid aqueous solution was a one-step irreversible reaction in the deposition process by cyclic voltammetry, which ensured the reliability of rare-earth hydroxide precipitation reaction.

Nanometer-thick molecular beam epitaxy Al films capped with in situ deposited Al2O3—High-crystallinity, morphology, and superconductivity

Achieving high material perfection in aluminum (Al) films and their associated Al/AlOx heterostructures is essential for enhancing the coherence time in superconducting quantum circuits. We grew Al films with thicknesses ranging from 3 to 30 nanometers (nm) epitaxially on sapphire substrates using molecular beam epitaxy (MBE). An integral aspect of our work involved electron-beam (e-beam) evaporation to directly deposit aluminum oxide (Al2O3) films on the freshly grown ultrathin epitaxial Al films in an ultra-high-vacuum (UHV) environment. This in situ oxide deposition is critical for preventing the oxidation of parts of the Al films, avoiding the formation of undesired native oxides, and thereby preserving the nm-thick Al films in their pristine conditions. The thicknesses of our Al films in the study were accurately determined; for example, coherence lengths of 3.0 and 20.2 nm were measured in the nominal 3.0 and 20 nm thick Al films, respectively. These Al films were epitaxially grown on sapphire substrates, showing an orientational relationship, denoted as Al(111)⟨21¯1¯⟩∥sapphire(0001)[21¯1¯0]. The Al/sapphire interface was atomically ordered without any interfacial layers, as confirmed by in situ reflection high-energy electron diffraction (RHEED) and cross-sectional scanning transmission electron microscopy (STEM). All sample surfaces exhibited smoothness with a roughness in the range of 0.1–0.2 nm. The Al films are superconducting with critical temperatures ranging from 1.23 to around 2 K, depending on the film thickness.

Impurity transport in PISCES-RF*

Abstract Linear plasma devices (LPD) utilizing a helicon plasma source, a high density light ion source, can generate impurities due to progressive erosion of the radio frequency (RF) transmission window caused by rectified sheath voltage. These source-born impurities can entrain and be transported by the plasma toward a target, affecting plasma-material interaction studies. Earlier work on material testing in Prototype-Materials Plasma Exposure eXperiment at ORNL revealed significant source impurity deposition on downstream targets. However, using a similar RF source, no target impurity deposition is observed in Plasma Interaction Surface Component Experimental Station (PISCES)-RF despite evidence of RF window erosion in the source region, thereby motivating the present work. Experimentally, using various magnetic field configurations upstream of the PISCES-RF plasma source and seeding titanium (Ti) impurities at various axial locations, impurity transport and deposition along the machine axis were investigated. It was found that Ti deposition was localized to the side of the plasma source where the Ti impurity was seeded. In contrast, aluminum (Al) deposition, originating from the sputtering of the helicon window, occurred predominantly upstream of the plasma source, suggesting an asymmetry in the axial transport of eroded RF window material. These observations suggest a stagnation of the parallel plasma flow immediately downstream of the plasma source, with impurity ions remaining unmagnetized near the source upstream. Al deposition in magnetic field-free regions in PISCES-RF indicates that sputtered Al impurities likely remained neutral due to their large ionization mean-free path under PISCES-RF conditions. Plasma modeling and simulation supported this, indicating that Al-neutrals transport toward the helicon source upstream for low electron density cases. It was found that the Larmor radius of the Al ions was greater than the plasma radius towards the source upstream and remained weakly magnetized in PISCES-RF, meaning that plasma source-born impurities are not efficiently entrained in the plasma flow. These findings provide critical insights into impurity transport in helicon plasma-based LPDs.

Current-carrying tribological properties and wear mechanisms of Mo-containing Cu alloy coatings produced by laser cladding

Copper alloy-molybdenum coatings were prepared on the surface of Cu-Cr-Zr alloys by laser cladding. The phase and microstructure were observed, and the hardness, conductivity, friction and wear properties under current-carrying conditions were tested. The results indicate that the prepared coatings exhibit good metallurgical bonding with the substrate. The Brinell hardness of the coatings ranges from 60 to 105 HB, and the electrical conductivity ranges from 17 % to 27 % IACS. The primary wear mechanism is abrasive wear and adhesive wear without current, resulting in the detachment of the Mo phase and transfer of the Cu phase during the sliding process. And it shifts to severe adhesive wear under current-carrying conditions, leading to the formation of aluminum deposit on the coatings.

Preferred crystal plane electrodeposition of aluminum anode with high lattice-matching for long-life aluminum batteries

Aluminum batteries have become the most attractive next-generation energy storage battery due to their advantages of high safety, high abundance, and low cost. However, the dendrite problem associated with inhomogeneous electrodeposition during cycling leads to low Coulombic efficiency and rapid short-circuit failure of the aluminum metal anode, which severely hampers the cycling stability of aluminum battery. Here we show an aluminum anode material that achieves high lattice matching between the substrate and the deposit, allowing the aluminum deposits to maintain preferred crystal plane growth on the substrate surface. It not only reduces the nucleation barrier of aluminum and decreases electrode polarization, but also enables uniform deposition of aluminum, improving the cycling stability of aluminum batteries. Aluminum anode with (111) preferred crystal plane can stably 25000 cycles at the current density of 5 A·g−1, with a capacity retention rate of over 80%.

Tunable Photoluminescence from Monolayer Molybdenum Disulfide

AbstractMonolayer molybdenum disulfide (1L MoS2), a promising optoelectronic material, emits strong visible photoluminescence (PL). Systematic control of the intensity, energy, and spectral width of PL from 1L MoS2 on silicon dioxide/silicon (SiO2/Si) is demonstrated via simple external treatments. Treating MoS2 with solutions formed from the superacid bis‐(trifluoromethanesulfonyl)amide (TFSA) enhances, blueshifts, and sharpens the PL. Treatments with solutions from structurally analogous chemicals that lack sulfur, in the case of bis(trifluoroacetamide) (BTFA), or lack fluorine, in the case of methanesulfonamide (MSA), show the same trend, suggesting a two‐component mechanism for TFSA involving the presence of electronegative species and sulfur vacancy passivation. Up to ≈100× enhancement of the PL intensity is achieved, with the peak blueshifted by ≈30 meV and the spectral linewidth halved. Conversely, direct thermal atomic layer deposition (ALD) of aluminum oxide (Al2O3) or hafnium oxide (HfO2) is found to suppress the PL by up to a factor of ≈3, redshift by up to ≈70 meV, and broaden by ≈3×. Single‐spot and mapping Raman/PL techniques are combined in a robust characterization process to associate changes in the PL character to charge doping. This work demonstrates the convenient tunability of the optical behavior of 1L MoS2 by varying the electron density.

Microstructure and oxidation of a Ni–Al based intermetallic coating formation on a Monel-400 alloy

Abstract The purpose of this work was to examine how the microstructure and oxidation characteristics of Monel 400 Alloy were affected by the low-temperature aluminizing method. Monel 400 alloy was subjected to a low-temperature aluminizing procedure for 2 and 4 h at 600, 650, and 700 °C. Pure aluminum powder was used as the source of aluminum deposition to prepare the packs for the process. The activator and inert filler utilized were ammonium chloride (NH4Cl) and Al2O3 powder, respectively. The coating surfaces were characterized using energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM), as well as X-ray diffraction (XRD) analysis. It was discovered that the through-thickness variance in the layer microstructure varied between 4 and 30 µm, and that it increased with greater process temperatures and times. The coating layer hardness grew to 800 HV after the deposition process, whereas the matrix hardness remained at 200 HVN. Furthermore, the sample that was coated at 600 °C for 4 h was exposed to oxidation at 750–800 and 850 °C. It was found that the oxidation kinetics were 176 kJ/mol.

Synergetic Optimization of Upper and Lower Surfaces of the SnO2 Electron Transport Layer for High-Performance n-i-p Perovskite Solar Cells.

The SnO2 electron transport layer (ETL) has been recognized as one of the most effective protocols for achieving high-efficiency perovskite solar cells (PSCs). To date, most research has primarily focused on the modification of the upper surface of SnO2 ETL films. The lower surface of the SnO2 film, which directly influences the film formation of solution-processed SnO2, is equally important but receives relatively less attention. Herein, we present a synergetic optimization approach involving the deposition of aluminum oxide (AlOx) via atomic layer deposition (ALD) as a buffer layer and the incorporation of rubidium acetate (RbAc) as an upper surface passivation additive. This process leads to a conformal coating of SnO2 nanoparticles, improved electrical performance, and higher-quality perovskite crystals. As a result, with this composite ETL film, the power conversion efficiency (PCE) reached 22.41 from 20.77%. Further modification with p-butyl iodide (BAI) on the perovskite upper surface increased the champion PCE to 23.32%, with a voltage loss of 0.41 V, ranking among the lowest values for the triple-cation mixed-halide perovskite absorber (1.58 eV). Importantly, the perovskite solar cells remained 87.30% of its initial performance after 14 days of aging and exhibited photostability under long-term UV (254 nm) illumination.

Rotating magnetic field improved cognitive and memory impairments in a sporadic ad model of mice by regulating microglial polarization.

Neuroinflammation, triggered by aberrantly activated microglia, is widely recognized as a key contributor to the initiation and progression of Alzheimer's disease (AD). Microglial activation in the central nervous system (CNS) can be classified into two distinct phenotypes: the pro-inflammatory M1 phenotype and the anti-inflammatory M2 phenotype. In this study, we investigated the effects of a non-invasive rotating magnetic field (RMF) (0.2T, 4Hz) on cognitive and memory impairments in a sporadic AD model of female Kunming mice induced by AlCl3 and D-gal. Our findings revealed significant improvements in cognitive and memory impairments following RMF treatment. Furthermore, RMF treatment led to reduced amyloid-beta (Aβ) deposition, mitigated damage to hippocampal morphology, prevented synaptic and neuronal loss, and alleviated cell apoptosis in the hippocampus and cortex of AD mice. Notably, RMF treatment ameliorated neuroinflammation, facilitated the transition of microglial polarization from M1 to M2, and inhibited the NF-кB/MAPK pathway. Additionally, RMF treatment resulted in reduced aluminum deposition in the brains of AD mice. In cellular experiments, RMF promoted the M1-M2 polarization transition and enhanced amyloid phagocytosis in cultured BV2 cells while inhibiting the TLR4/NF-кB/MAPK pathway. Collectively, these results demonstrate that RMF improves memory and cognitive impairments in a sporadic AD model, potentially by promoting the M1 to M2 transition of microglial polarization through inhibition of the NF-кB/MAPK signaling pathway. These findings suggest the promising therapeutic applications of RMF in the clinical treatment of AD.

Boosting Aluminum Adsorption and Deposition on Single‐Atom Catalysts in Aqueous Aluminum‐Ion Battery

AbstractIn the quest for sustainable energy storage technologies, lithium‐based batteries, despite their prominence, face limitations such as high costs, safety risks, and supply chain issues. This has propelled the exploration of alternative materials, with aqueous aluminum‐ion batteries (AAIBs) emerging as a promising candidate due to their high energy density, abundance, and cost‐effectiveness. However, the low equilibrium reduction potential of aluminum ions presents significant challenges, including hydrogen evolution and poor cyclability. Addressing these, the study pioneers the application of single‐atom catalysts (SACs) in AAIBs, leveraging their high atom utilization and stability to enhance aluminum deposition and suppress hydrogen evolution. Sn, In, Cu, and Ni SACs are evaluated through density functional theory analysis and experimental validation, with Sn SAC identified as the most effective. Subsequently, the Sn SAC based anode demonstrates enhanced performance, achieving stable cycling over 500 h at 0.5 mA cm−2, significantly improved capacity retention (60 mAh g−1@300 cycles), and rate performance (50 mAh g−1@1 A g−1) in full cell tests. This work underscores the potential of SACs in advancing AAIB technology and opens new pathways for energy storage solutions.

Laser deposition of aluminum and magnesium‑based alloys for repair and surface restoration of components

The results of studying the processes of laser deposition of aluminum and magnesium‑based alloys, the features of the structure of deposited layers using electron microscopy and X‑ray computed tomography data, measurements of microhardness after laser deposition of aluminum and magnesium alloys are presented. Modeling of the stress‑strain state of flat components during laser deposition of an aluminum‑magnesium alloy containing 0.6–0.95 % magnesium, 0.7–1.0 silicon, up to 0.3 titanium, up to 0.5 zinc, and up to 0.4 % manganese was performed. The nature of the distribution of deformations and stresses during the use of various technological schemes of laser deposition during surface treatment of aluminum‑magnesium alloys by laser deposition methods is established.