Pure Aluminum Research Articles

High-strength and lightweight alloy materials for new energy vehicles

Abstract The Fe-8wt. % Al alloy ingot was obtained by melting the pure iron and the pure aluminum together. The four plate samples were prepared by cold rolling the ingots with certain thicknesses by 80%, 70%, 63%, and 50%. The four samples were annealed at 850°C, 900°C, 950°C and 1000°C in air and kept for 5 min, 10 min and 15 min before quenching. The Fe-8wt. % Al alloy ingot was obtained by melting the pure iron and the pure aluminum together. The four plate samples were prepared by cold rolling the ingots with certain thicknesses by 80%, 70%, 63%, and 50%. The four samples were annealed at 850°C, 900°C, 950°C and 1000°C in air and kept for 5 min, 10 min and 15 min before quenching. It is revealed that the sample’s structure was optimized when the sample was cold rolled by 80%, annealed at 900°C for 10 min, and quenched. This also led to a maximum extension. It is revealed that the sample’s structure was optimized when the sample was cold rolled by 80%, annealed at 900°C for 10 min, and quenched, also this led to a maximum.

The effect of severe plastic deformation on the mechanical properties of aluminum composite obtained by additive printing

Abstract The composite material for the study was obtained by wire-arc additive manufacturing on the basis of AA1050 (commercially pure aluminum) and AA5056 (commercial alloy of the Al-Mg system) aluminum alloys. The influence of the degree of deformation by high-pressure torsion technique on the mechanical properties and microstructure of the composite material was investigated. The dependences of the static strength and plasticity of the material on the degree of deformation were obtained. The microstructure of the material was investigated by scanning electron microscopy and X-ray diffraction analysis. The optimal deformation route providing the best combination of mechanical properties is revealed, the key microstructure parameters providing optimal properties are determined.

Analysis of the Anisotropic Cyclic Material Behavior of EN AW-1050A H24 Derived from Strain-Controlled Testing Using a Clip-On Extensometer and an Optical System

Due to its good conductive properties, unalloyed (pure) aluminum, such as EN AW-1050A H24, finds new fields of application in electromobility. To optimize components, the cyclic material behavior must be understood and described precisely as a foundation of a proper fatigue life estimation. Various cyclic tests were performed to not only derive the cyclic parameters to describe the material but also to find the most suitable procedure to deal with the challenges faced during the experiments. The main point of interest is the comparison between a surface-mounted clip-on extensometer and an optical system both used for strain control in cyclic tests. For the analysis of the anisotropic behavior of EN AW-1050A H24, un-notched flat specimens were extracted from sheet metal lengthways and crossways in respect to the rolling direction. While the cyclic material behavior for specimens of both directions of extraction is characterized by cyclic softening in general, the specimens extracted crossways show a strain-amplitude-dependent cyclic softening with strong strain localization especially at the contact points of the knives of the clip-on extensometer leading to an increased quantity of invalid experiments as well as sudden fractures. In the study, it was possible to show the benefits of a contactless optical strain control system when dealing with very soft metallic materials such as EN AW-1050A H24.

Finite Element Modeling and Experimental Verification of a New Aluminum Al-2%Cu-2%Mn Alloy Hot Cladding by Flat Rolling

The roll bonding of an experimental Al-2%Cu-2%Mn alloy with technically pure 1050A aluminum at true deformations of 0.26, 0.33 and 0.40 has been simulated using the QForm 10.3.0 FEM software. The flow stress of the Al-2%Cu-2%Mn alloy has been measured in temperature and strain rate ranges of 350–450 °C and 0.1–20 s−1, respectively. The simulation results suggest that the equivalent strain in the cladding layer is more intense than that in the base layer, reaching 1.0, 1.4 and 2.0 at strains of 0.26, 0.33 and 0.40, respectively. The latter fact favors a decrease in the difference between the flow stresses of the rolled sheet layer contact surfaces by an average of 25% at the highest strain. The experimental roll bonding has achieved good layer adhesion for all the test samples. The average peeling strength of the samples produced at strains of 0.26 and 0.33 proves to be 12.6 and 18.4 N/mm, respectively, and at a strain of 0.40, it has exceeded the flow stress of the 1050A alloy cladding layer. The change in the rolling force for different rolling routes has demonstrated the best fit with the experimental data.

Effect of applied load on wear of microwave sintered alumina-graphene ceramic composite material

The present work is mainly focussed on the preparation of alumina ceramic composite material reinforced with different weight proportions (wt%) of graphene ranging from 0.15 wt% to 0.45 wt% (with an interval of 0.1) and fabrication using microwave sintering method. Wear studies are performed on graphene reinforced alumina ceramic material samples using pin-on-disk apparatus at different loads of 5 N, 10 N, 15 N keeping speed of 0.8 m s−1 and sliding distance of 40 m constant. The obtained wear results are compared with wear performance of pure alumina samples which are prepared in the same condition. Wear tests even at higher load of 15 N revealed that the decrease in the wear rate of the ceramic composite samples reinforced with 0.35 wt% of grapheme is 35.14% and in the ceramic composite samples reinforced with 0.45 wt% of graphene is 34.85% when compared with the wear rate of samples prepared with pure alumina. The effect of different wt%s of graphene on wear properties of prepared ceramic composites is studied through SEM analysis, and observed that the abrasive wear phenomenon is found to be the dominant wear mechanism.

Finite Element Simulation of Multi-Pass Rolling of a Pure Aluminum Target under Different Rolling Routes and Methods

By coordinating the rolling direction and mode, a multi-rolling plastic deformation process for an aluminum (Al) sputter target is proposed to achieve multiple excellent properties, including a uniform and fine grain structure and low defect risk, which are significant in producing high-quality sputtered films. In this work, therefore, DEFORM 3D 10.2 software is adopted to establish three strategies, clock-synchronous rolling, cross-synchronous rolling, and clock–snake rolling. The effect of different rolling routes and modes on the metal flow velocity (MFV), effective strain distribution (ESD), grain size distribution (GSD), damage, and rolling force (RF) are comparatively investigated. The simulation results show that clock–snake rolling can increase the MFV and effective strain by producing a deeper deformation than the others. It provides sufficient energy for dynamic recrystallization to promote grain refinement. In combination with the microstructure homogeneity promoted by the clock rolling route, the GSD from 6.5 to 44.3 μm accounts for about 80.5% of all the grains because of the fact that a randomly oriented grain region is full of high-angle grain boundaries. Compared with the synchronous rolling mode, the decrement in RF maximum reaches up to 51% during the asynchronous rolling process because component energy is consumed to form cross-sheering stress. It remarkably reduces the risk of defects, with a damage value of less than 73%, and simultaneously improves energy efficiency owing to smaller and uniform grains caused by less RF. The results obtained in this work are of great significance as they can guide practical production in the metal target industry.

Effects of Materials and Riblets on Erosion Mitigation Induced by Multiple Collapses of Cavitation Bubbles

The current research investigates the effects of materials and riblets on cavitation-induced erosion morphology, depth, and cross-sectional area through experimental approaches. To achieve these aims, the erosion of pure aluminum (1xxxAl or Al) and alpha brass (CuZn37 or CZ108), in the presence and absence of bio-inspired sawtooth riblets, was examined after exposure to multiple collapses of single cavitation bubbles with a wall distance of 1.8 (dimensionless). The results indicate that the erosion morphology resembles a rounded cone with a circular cross-section. Brass provides 21.6% more erosion resistance compared to that of Al in terms of material properties. Furthermore, the erosion for both Al (depth by 3.8% and width by 18.3%) and brass (depth by 7.9% and width by 27.4%) decreases in the presence of riblets compared to the results for flat surfaces. The greater erosion resistance of brass compared to Al is attributed to the superior mechanical stability of brass, making it a potentially suitable alloy for use in propellers and hulls in the shipping industry. In summary, the results reveal that riblet-equipped materials with high mechanical durability are promising erosion-resistant materials for the shipping industry. However, the potential for chemical reactions in a cathodic environment should be addressed to provide a comprehensive perspective in regards to reducing corrosion intensity.

Wear characteristics of a CNTs reinforced aluminium composited fabricated by the solution mixing process

Aluminium-carbon nanotube (Al-CNT) composites have proven to offer a lot of potential for applications involving friction and wear. This study investigated the wear behaviour of Al-CNT composites with uniformly dispersed CNTs without structural damage at concentrations of 0.5 wt%. The wear behaviour of these composites has been compared with that of pure aluminium, which was fabricated using the identical wet shake mixing, compaction, and extrusion procedure. The study aimed to determine how CNT concentration and applied stress influence the wear behaviour of composite materials. Scanning electron microscope (SEM) was used by the researchers to examine the surface features of the worn samples. The study showed a significant increase in hardness and wear resistance with adding CNT. Compared to pure aluminium, the composite containing 0.5 wt. % CNTs demonstrated a 25% reduction in wear rate, and the average value of the coefficient of friction (µ) also decreased. The wear rate and coefficient of friction increased when samples containing 0.5 wt. % CNTs were subjected to various loading scenarios. The major contribution of CNTs to improving wear characteristics was discovered through SEM investigation of these worn surfaces. Using the ANSYS Workbench, a built finite element model was used to perform contact analysis on the disc and pin. Analytical results and experimental data were contrasted, and the ANSYS data was utilised to assess the process parameters. The comparison confirmed the analysis accuracy and dependability, which showed a consistent agreement between the analytical findings and the experimental results.

The Enhancement Discharge Performance by Zinc-Coated Aluminum Anode for Aluminum–Air Battery in Sodium Chloride Solution

The main drawback of seawater batteries that use the aluminum (Al)–air system is their susceptibility to anode self-corrosion during the oxygen evolution reaction, which, in turn, affects their discharge performance. This study consist of an electrochemical investigation of pure Al, 6061 Al alloy, and both types coated with zinc as an anode in a 3.5% sodium chloride (NaCl) electrolyte. The electrolyte solution used for the deposition of zinc metal contained citrate, with and without EDTA as a complexing agent. Subsequently, the performance of the anode was tested in a seawater battery, using a carbon@MnO2 cathode and a 3.5% NaCl electrolyte. The performance of Al–air batteries has been significantly enhanced by applying a process of electrodepositing zinc (Zn) with a citrate deposition electrolyte solution in both pure aluminum and alloy 6061. The performance of the battery was further enhanced by adding EDTA as a chelating agent to the citrate-based electrolyte solution. The Al–air battery with aluminum alloy 6061 with Zn electrodeposition with an additional EDTA as the anode, carbon@MnO2 as the cathode, and NaCl 3.5% solution as the electrolyte has the highest battery performance, with a specific discharge capacity reaching 414.561 mAh.g−1 and a specific energy density reaching 0.255 mWh.g−1, with stable voltage at 0.55 V for 207 h.

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.

Nature-Inspired Incorporation of Precipitants into High-Strength Bulk Aluminum Alloys Enables Life-Long Extraordinary Corrosion Resistance in Diverse Aqueous Environments.

The safe service and wide applications of lightweight high-strength aluminum alloys are seriously challenged by diverse environmental corrosion, since high strength and corrosion resistance are mutually exclusive for metals while surface protection cannot provide life-long corrosion resistance. Here, inspired by fish secreting slime from glands to resist external changes, a strategy of incorporating precipitants as the slime into bulk metals using the inner cavity of opened carbon nanotubes (CNTs) as the glands is developed to enable high-strength aluminum alloys with life-long superior corrosion resistance. The resulting material has ultrahigh tensile strength (≈700MPa) and extraordinary corrosion resistance in acidic, neutral and alkaline media. Notably, it has the highest resistance to intergranular corrosion, exfoliation corrosion and stress-corrosion cracking, compared with all previously reported aluminum alloys, and its corrosion rate is even much lower than that of corrosion-resistant pure aluminum, which results from the pronounced surface enrichment of precipitants released (secreted) from exposed CNTs forming a protective surface film. Such high corrosion resistance is life-long and self-healing due to the on-demand minimal self-supply of the precipitants dispersed throughout the bulk material. This strategy can be readily expanded to other aluminum alloys, and could pave the way for developing corrosion-resistant high-strength metallic materials.

Development and characterization of powder metallurgy processed Al/Fe/SiC/MoS2 hybrid composites

This study explores hybrid aluminum matrix composites through powder metallurgy, incorporating silicon carbide, iron, and molybdenum disulfide at varying weight percentages (5%, 10%, and 15%). Defect-free hybrid composites with a uniform distribution of reinforcing particles were fabricated and characterized for microstructure, hardness, density, and wear. The EDX spectra show peaks consistent with Al, Fe, SiC, and MoS2, confirming their presence in developed hybrid composites. The pure aluminum sample presents a relative density higher than that of hybrid composites, while its hardness is lower (25%–41%) than that of hybrid composites. The wear rate decreased with the amount of reinforcing particles. The presence of hard silicon carbide, iron, particles, and lubrication by molybdenum disulfide effectively enhanced the wear behavior of hybrid composites.

Influence of Grain Size and Film Formation Potential on the Diffusivity of Point Defects in the Passive Film of Pure Aluminum in NaCl Solution

The influence of grain size on the corrosion behavior of pure aluminum and the defect density and diffusion coefficient of surface passive films were investigated using electron backscatter diffraction (EBSD) and electrochemical testing techniques, based on the point defect model (PDM). Samples with three different grain sizes (23 ± 11, 134 ± 52, and 462 ± 203 μm) were obtained by annealing at different temperatures and times. The polarization curves and electrochemical impedance spectroscopy results for the pure aluminum in the 3.5% NaCl solution showed that with decreasing grain size, the corrosion current (icorr) decreased monotonously, giving rise to a noble corrosion potential and a large polarization resistance. The Motte–Schottky results showed that the passive films that formed on pure aluminum with fine grains of 23 ± 11 μm had a low density (3.82 × 1020 cm−3) of point defects, such as oxygen vacancies and/or metal interstitials, and a small diffusion coefficient (1.94 × 10−17 cm2/s). The influence of grain size on corrosion resistance was discussed. This work demonstrated that grain refinement could be an effective approach to achieving high corrosion resistance of passive metals.

Critical Challenges in the Anodizing Process of Aluminium–Silicon Cast Alloys—A Review

The microstructure of the substrate plays a crucial role in the anodizing process. Anodizing cast aluminum alloys is quite challenging due to the higher levels of alloying elements present compared to pure aluminum. Elements such as silicon, iron, and copper significantly impact the growth and quality of the anodic layer. Additionally, anodizing parameters such as electrolyte composition, current density, and temperature are critical in determining the morphology and thickness of the anodic film. The casting process, surface condition, and post-treatment also affect the properties of the anodic layer. Optimizing these parameters is essential to achieve a durable and high-quality anodic layer. This work aims to provide a comprehensive understanding of the various factors affecting the anodizing of cast aluminum alloys and the properties of the anodic layer, including its thickness, corrosion resistance, and wear resistance.

Effect of Nb2O5 doping on low-temperature sintering of TiO2-Al2O3 ceramics

This study investigates the effects of Nb2O5 as a dopant in TiO2–Al2O3 ceramics to lower sintering temperature and enhance performance, including the physical, mechanical, and dielectric properties of the ceramics at sintering temperatures 1250 °C–1350 °C. Specifically, TiO2–Al2O3 ceramics doped with 1.5 wt% Nb2O5 and sintered at 1350 °C exhibit remarkable density 94 %, compressive strength 1372 MPa, and abrasion resistance 1.36 × 10−4 mm3/N·m, surpassing those of pure alumina ceramics. This improvement is attributed to enhanced grain boundary diffusion and strain energy resulting from Nb5+ cation substitution. The incorporation of Nb2O5 in TiO2–Al2O3 ceramics reduce sintering temperatures by 150–200 °C. The dielectric constant of TiO2–Al2O3 ceramics doped with 1.5 wt% Nb2O5 sintered at 1350 °C is found to be 13.4, with a dielectric loss of 2.56 × 10−2 and insulation resistance 7.3 × 1012 Ω. Nb2O5 is an effective additive for reducing sintering temperatures in Al2O3 based ceramic.

Tribo-mechanical performance of Al-nano TiC composites processed by microwave-assisted powder metallurgy

This study aims to investigate the microstructural, mechanical, and tribological characteristics of Al-nano TiC composites. The microwave-sintered nanocomposites were analyzed using optical and scanning electron microscopes, providing valuable insights into the spatial distribution and interaction of TiC within the matrix material. Microstructure characterization confirmed the uniform dispersion of nano TiC particles throughout the Al. Furthermore, the microwave-sintered nanocomposite samples displayed greater hardness than pure aluminum, indicating the strengthening impact of nano-TiC. Al-6 wt.% nanocomposites fabricated using microwave-sintered powder metallurgy showcased an impressive hardness rating of 51 VHN. The assessment of tribological properties revealed that a higher TiC concentration reduced wear rate, showcasing improved surface protection. However, it was observed that the friction coefficient rise with the addition of nano-TiC particles, implying changes in the bonding between the composite and the interacting surface. The thorough examination of worn surfaces yielded insights into the wear mechanisms present in the nanocomposite materials. Detailed examination of worn surfaces highlighted the formation of protective oxide layers, contributing to the improved wear resistance. This research contributes to our understanding of the complex interactions occurring during tribological processes by clarifying the morphological features of worn surfaces.

On the microstructure and hardness evaluation of aluminum metal matrix composites reinforced with in situ (Fe-Al-Cr-Ni) intermetallic compounds

Abstract In this study, Aluminum metal matrix composites (AMMCs) were produced through stir casting technique, using in situ intermetallic compounds as reinforcement. The in situ synthesis of these reinforcement phases involved the addition of stainless-steel particles (type 316L) at various weight percentages of 5, 10, and 15 wt. %. The impact of varying the amount of stainless particles added on the hardness and microstructure of the resulting AMMCs was examined. X-ray diffraction patterns (XRD) and energy dispersive spectroscopy (EDS) analysis reveal the formation of two types of intermetallic compounds: iron aluminide intermetallic compounds in irregular plate and needle-like morphologies and another one with higher percentage of Cr in a hexagonal-plate like morphology. Microstructural characterization shows a reputable distribution of the newly formed intermetallic phases. The findings indicate that the hardness of the composites improves as the stainless particles content increases. Hardness of the AMMC fabricated by adding 15 wt.% stainless steel was tripled compared with that of pure aluminium.

Tensile and Fracture Behaviour of Sn/Pb Solder Affected Aluminium Subjected to Post-Deformation Ageing

An efficient assessment of the mechanical characteristics of waste/scraped aluminum under a variety of operating circumstances is crucial to the exploration of its potential for reuse. In this regard Sn/Pb solder affected aluminum is subjected to post-deformation and ageing in order to investigate its effect on tensile and fracture behaviour. To isolate the individual effects pure Al, binary Al-Sn and Al-Pb alloy samples are taken simultaneously. Cold rolled by 80% and aged at different temperatures are then tensile tested at room temperature with a different strain rate. Results are the solder affected samples improved in strength through solid solution strengthening whereas tin performed better than lead because Sn has a different BCC crystal structure than that of FCC Al and Pb. Quantitative analysis indicates that at the peak aged condition the strength of pure aluminium is improved by 21%, 9% and 29% when affected by Sn, Pb and Sn-Pb solder respectively. Tin forms various intermetallics with different impurities hence there is some ageing response. These precipitates have an effect on the strain rate and accelerate the tensile strength. The effects of elements on the reduction of impact strength are noticeable. Minor added alloys show relatively dense grain boundaries for the presence of different elements. Such elements are visible on the fracture surface, which inhibits dislocation movement and ensures high strength. IUBAT Review—A Multidisciplinary Academic Journal, 7(1): 186-201

Challenges by latent heat calculation – Competition among analytical and computational methods

Determining the latent heat of multi-component cast aluminum alloys is complex. These alloys solidify within the mushy zone, with their latent heat release influenced by factors like composition, cooling rate, and microstructure. Techniques such as DSC and DTA, along with software tools like JMatPro, FactSage, and ThermoCalc, can determine this value, understand solidification parameters, and calculate latent heat. This paper introduces a novel approach using Newtonian, Fourier, and Energy Balance methods simultaneously, for the first time, to calculate the latent heat of pure aluminum and its AlSi7Cu1 alloy. These methods offer advantages in foundry conditions and require no specialized operator for data interpretation. Commercial software typically provides parameters for standard alloys only, necessitating alternative sources for accurate data. Thermal analysis techniques offer a reliable method to acquire missing parameters and calculate latent heat with high precision. Comparing the accuracy of these methods for pure aluminum and its AlSi7Cu1 alloy, using DSC measurement data and commercial software values, indicates successful application on the foundry floor to determine thermophysical properties accurately.

Effects of Main Alloying Elements on Interface Reaction between Tool Steel and Molten Aluminum

Effects of Si and Mg as main elements on interface reaction between tool steel and molten Al alloy at 700°C were investigated. Pure aluminum and Al-10mass%Mg alloy showed relatively simple interfacial layers, whereas thicker, multi-layered reaction bonds were found in the diffusion couple of A380 alloy. The diffusion of a large amount of Fe into Al matrix throughout the interfacial layer led to the formation of Al-Fe based intermetallic particles in the Al base metals. The diffusion couple of Al-10mass%Mg alloy showed a similar intermetallic layer as that of pure Al, indicating that 10mass%Mg in the Al melt rarely affected the formation of Al-Fe intermetallic layers. However, A380 alloy showed much expanded soldering area and increased thickness of intermetallic layers. Based on the phase diagram calculated, the solubility of Fe in liquid Al increased significantly with increasing Si content up to apploximately 5mass%, while, in the case of 10mass%Mg addition, the Fe solubility gradually decreased with increasing Mg content. Al-10mass%Mg alloy also showed the same tendency as that of pure Al in the formation and distribution of intermetallic compounds. However, in the Al-12mass%Si alloy, two types of Al-Fe-Si ternary compounds are present on the Al-rich side.