Article

Aluminium: The metal of choice

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Abstract

This article summarizes the importance of aluminium as the metal of choice for many applications. Aluminium is a lightweight, durable metal. It is silvery in appearance when freshly cut, is a good conductor of heat and electricity, and is easily shaped by moulding and extruding. Aluminium has two main advantages when compared with other metals. Firstly, it has a low density, about one-third that of iron and copper. Secondly, although it reacts rapidly with the oxygen in air, it forms a thin, tough and impervious oxide layer that resists further oxidation. This removes the need for surface-protection coatings such as those required with other metals, in particular with iron. All the indications are that the growth in the use of aluminium will likely accelerate. It is expected that in the near future the use of aluminium with specifically improved properties will grow in many applications, meeting the increased economic and ecological demands. Considering the entire life-cycle of an automobile, from the extraction of materials to the final disposal, including recycling and reuse applications, aluminium proves to be a potential alternative to steels in future automotive applications.

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... Aluminum is a metal that is lightweight and durable, silver when cut, good conductor of heat and electricity, and easily formed by molding and extrusion. Aluminum also has excellent thermal properties and corrosion resistance has its use in air conditioning, cooling and heat exchange systems [2]. Utilization of aluminum waste from used beverage cans to produce hydrogen gas. ...
... W = E x I x t (2) [16] Where -W = Mass -E = Valence -I = Current ...
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The production of hydrogen gas as an alternative fuel cell which is a renewable energy, is now in great demand by utilizing waste aluminum beverage cans and added water using NaOH catalyst by electrolysis process. The research method will be carried out by inserting 1 gram of aluminum pieces into a tube and 300 ml of distilled water followed by a NaOH catalyst. Both faucets are opened to release air during the filling process. The faucet is closed when the height of the solution in both tubes is the same. Then turn on the DC flow, then adjust the voltage according to the variable. The filling period is recorded until the specified reaction time. The results of the gas volume obtained are recorded, and the hydrogen obtained is determined by the flame test. From the research it can be concluded that the hydrogen gas produced from the reaction can be identified by means of a flame test. The characteristics of hydrogen gas appear in flames which tend to disappear in the air. At Al 5 gr Weight : 5 M NaOH concentration is the largest volume of hydrogen. The reaction time of 150 minutes will produce a lot of hydrogen gas. The largest volume of hydrogen gas lies at a voltage of 20 volts.
... For instance, the elastic limit of the aluminum is 280 MPa. 51 Hence, the fabricated aluminum specimen is mechanically strained to a maximum tensile load of 160 MPa with a strain rate of 1 mm min −1 using a uniaxial tensile machine, as shown in Figure 6a. As a resultant of applied tensile force, the aluminum specimen experiences the strain (ε) and it is transmitted to the bonded flexible strain sensor in which electrical conductive network formed by the HEG nanofillers gets distorted. ...
... For instance, the elastic limit of the aluminum is 280 MPa. 51 Hence, the fabricated aluminum specimen is mechanically strained to a maximum tensile load of 160 MPa with a strain rate of 1 mm min −1 using a uniaxial tensile machine, as shown in Figure S1f. The resultant change in the electrical resistance value is simultaneously measured using a Keithley 2450 source measurement unit. ...
Article
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In recent times, flexible piezoresistive polymer nanocomposite-based strain sensors are in high demand in wearable devices and various new age applications. In the polymer nanocomposite-based strain sensor, the dispersion of conductive nanofiller remains challenging due to the competing requirements of homogenized dispersion of nanofillers in the polymer matrix and retaining of the inherent characteristics of nanofillers. In the present work, waterproof and flexible poly(vinylidene difluoride) (PVDF) with a polymer-functionalized hydrogen-exfoliated graphene (HEG)-based piezoresistive strain sensor is developed and demonstrated. The novelty of the work is the incorporation of polystyrene sulfonate sodium salt (PSS) polymer-functionalized HEG in a PVDF-based flexible piezoresistive strain sensor. The PSS-HEG provides stable dispersion in the hydrophobic PVDF polymer matrix without sacrificing its inherent characteristics. The electrical conductivity of the PVDF/PSS-HEG-based strain sensor is 0.3 S cm–1, which is two orders of magnitude higher than the PVDF/HEG-based strain sensor. Besides, near the percolation region, the PVDF/PSS-HEG shows a maximum gauge factor of 10, which is about two times higher than the PVDF/HEG-based flexible strain sensor and 5-fold higher than the commercially available metallic strain gauge. The enhancement in the gauge factor is due to the stable dispersion of PSS-HEG in the PVDF matrix and electron conjugation caused by the adherence of negatively charged sulfonate functional groups on the HEG. The developed waterproof flexible strain sensor is demonstrated using portable wireless interfacing device for various applications. This work shows that the waterproof flexible PVDF/PSS-HEG-based strain sensor can be a potential alternative to the commercially available metallic strain gauge.
... It is easy to recycle due to its light weight, which in turn makes it easier to be transported. The production of new aluminium alloy elements from recycled components requires a minor amount of energy consumption and emits less greenhouse gas [46][47][48][49]. ...
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A large percentage of existing building stock in Italy and throughout Europe is ageing and no longer complies with current regulations, particularly in terms of sustainability. For these reasons, an urgent consolidation plan is needed to ensure an increase in both seismic response and energy response. Indeed, these constructions were built before the actual technical codes, and currently, they are not able to withstand seismic actions. Meanwhile, they are subject to thermal dispersions that could be due to the use of materials with poor properties or construction errors. Among the numerous consolidation techniques, an innovative solution consisting of a coating system has appeared on the construction market in recent decades. It is an integrated solution that simultaneously improves the seismic and energy behaviour of the building. The paper proposes the evaluation of this lightweight and sustainable solution through some experimental tests which were performed at the National Institute for Research and Development in Constructions, located in the city of Timişoara (Romania). The tests were aimed to investigate the out-of-plane behaviour of a masonry wall (1.20 m × 2.40 m × 0.60 m) obtained by combining two smaller panels with mortar and subjecting them to constant vertical force and pushing by an increasing horizontal one. Its response was assessed before and after the application of extruded aluminium alloy base profiles belonging to the system under study.
... Aluminum alloys are fully recyclable and can be recycled repeatedly with no degradation of physical and chemical properties [139][140][141]. Recycling aluminum alloys is an important process that has numerous environmental and economic benefits. ...
... In fact, the average corrosion rate reported for carbon steel is 0.2 mm/year [72]. Two potential alternatives to carbon steel, namely aluminium alloys and duplex stainless steel, are well known to be more corrosive resistant; therefore, they have lower maintenance requirements [68,73,74]. In contrast, composites are free from corrosion. ...
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Material selection is a crucial aspect in the design of reliable, efficient and long-lasting wave energy converters (WECs). However, to date, the development of tailored methodologies applied to the material selection of WECs remains vastly unexplored. In this paper, a material selection framework for the case of lift-based WECs is developed. The application of the methodology is demonstrated with the hydrofoils of the device. Offshore steel, high-strength offshore steel, aluminium alloys, and carbon-and glass-fibre-reinforced composites are considered and evaluated subject to relevant criteria for wave energy converters, namely structural reliability, hydrodynamic efficiency, offshore maintainability, total manufacturing cost and environmental impact. Candidate materials are assessed via fuzzy TOPSIS for three scenarios of the life cycle of the WEC: conceptual, commercial and future projection stages. Results show that the choice of optimal materials could change from present to future and that multi-criteria decision-making tools aided by a fuzzy approach are useful design tools for novel WECs when field data are scarce. Hence, methodologies such as the ones presented in this work can help in reducing the probability of mechanical failures of emerging WEC technology.
... Different aluminum alloys are constantly developed to address the needs of the market. Plasma technologies are usually used for thin film coatings on aluminum materials to promote its properties [1][2]. In the foreseeable future, materials development is expected to progress in two different directions. ...
Article
The plasma system was applied on two different powder system suspensions of Al-Ni and Al-Mo to synthesize different phases using a combinatorial approach. Effects of different process variables such as power level, reactor pressure, powder suspension characteristics, etc. on the characteristics of each set of powders formed separately from the mentioned suspended powder mixtures were investigated. Irrespective of the applied powder suspension system, the obtained powders contained large spherical particles that were surrounded by a cloud of fine porous particles. Different phases such as Al, Mo, Al5Mo, Mo2C, Al4C3 and AlOx were detected in the particles of the Al-Mo powder system and Al, Ni, Al4C3, AlNi, AlOx and Al3Ni in those of the Al-Ni powder system. The reasons for the formation of carbides and oxides were investigated and attributed to the air leaks that occurred during the process of solidification and/or the presence of an oxygen-laden liquid in the suspensions.
... Aluminium is one of the most widely used industrial products to date [3]. This is because it can be formed into multiple alloys with dierent properties, it is non-corrosive and most importantly it is 100% recyclable. ...
Thesis
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This document presents the development of a solution for analysis and detection of molten metal quality deviations. The data is generated by an MV20/20, an ultrasound sensor that detects inclusions - molten metal defects that affect the quality of the product. The data is then labelled by assessing the sample using metallography. The analysis provides the sample outcome and dominant inclusion. The business objectives for the project include the real-time classification of anomalous events by means of a supervised classifier for the metal quality outcome, and a classifier for the inclusion type responsible for low quality. The adopted methodology involves descriptive, diagnostic and predictive analytics. Once the data is statistically profiled, it is standardised and scaled to unit variance in order to compensate for different units in the descriptors. Principal components analysis is applied as a dimensionality reduction technique, and it is found that the first three components account for 99.6% of the variance of the dataset. In order for the system to have predictive ability, two modelling approaches are considered, namely Response Surface Methodology and supervised machine learning. Supervised machine learning is preferred as it offers more flexibility than a polynomial approximator, and it is more accurate. Four classifiers are built, namely logistic regression, support vector machine, multi-layer perceptron and a radial basis function network. The hyperparameters are tuned using 10- fold repeated cross-validation. The multi-layer perceptron offers the best performance in all cases. For determining the quality outcome of a cast (passed or failed), all the models perform according to business targets for accuracy, precision, sensitivity and specificity. For the inclusion type classification, the multi-layer perceptron performs within 5% of the target metrics. In order to optimise the model, a grid search is performed for optimal parameter tuning. The results offer negligible improvement, which indicates that the model has reached a global maximum in the parameter optimisation in the hyperspace. It is noted that the source of variance in the inclusion type data respondent is attributed to operator error during labelling of the dataset, among several other sources of variance. It is therefore recommended that a Gage R&R be performed in order to identify sources of variation, among other improvement recommendations. From a research perspective, a vision system is recommended for assessing metal colour, texture and other visual properties in order to provide more insights. Another possible research extension recommended is the use of Fourier Transform Infrared Spectroscopy in determining signatures of the clean metal and different inclusions for detection. The project is regarded as a success, as the business metrics are met by the solution.
... As a result, it is frequently utilized in a variety of industries, among which are those that involve with transportation, electricity, building and construction, machinery, and equipment, food processing, packaging, and storage, as well as a wide range of home appliances. It is used in the manufacturing of personal hygiene and health care items such as toothpaste, antiperspirants, acne treatments, dermal care, antacids/antiulcerative medications, vaccines, and antidiarrheal medications (Gándara, 2013;Ng et al., 2017;and Rahimzadeh et al., 2022(. Moreover, it is frequently used as a food ingredient as a buffer, firming agent, dyeing agent, anticaking agent, neutralizing agent, dough stabilizer, thickener and curing agent (Yeh et al., 2016 andYokel, 2016). ...
... Please Aluminum (Al) is one of the non-ferrous metals that has several advantages, including having a light specific gravity, corrosion resistance, and good electrical conductivity. The basic nature of pure Al is to have good castability but low mechanical properties [1] and [2]. ...
... Bauxite is the most abundant mineral in the earth's crust, and aluminum derived from bauxite is the third most used metal in the world (Izbire 2013;Donoghue et al. 2014;Vind et al. 2018;Dey 2022). Aluminum manufacturers across the globe still rely on Bayer's process developed in 1887 for extracting the alumina from bauxite ore (Das and Yin;Rai et al. 2017;Wang et al. 2019). ...
Article
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The mining industry has powered the human endeavor to make life more innovative, flexible, and comfortable. However, it has also led to concerns due to the increasing amount of mining and associated industrial waste. Special attention is highly desired for its proper management and safe disposal in the environment. The problem has only augmented with the increase in the mining costs because of the investments needed for ecological remediation after the mining operation. It is pertinent that the targeted technologies need to be developed to utilize mining and associated industrial waste as a secondary resource to ensure sustainable mining operations. Every perceived waste is a valuable resource that is needed to be utilized to create additional value. In this review, the case of alkaline bauxite residue (red mud)—alumina refinery waste has been discussed at length. The highlight of the proposed work is to understand the importance of alkaliphile-assisted biomining—a sustainable alternative to conventional metal recovery processes. Along with the recovery of metals, pH reduction of red mud is possible through biomining, which ultimately paves the way for its complete utilization. The unique adaptation strategies of alkaliphiles make them more suitable for biomining of red mud through bioleaching, biosorption, and bioaccumulation, which have been discussed here. Furthermore, we have focused on the potential of the indigenous microflora of red mud for metal recovery in addition to its neutralization. The study of indigenous alkaliphiles from red mud, including its isolation and propagation, is crucial for the industrial-scale application of alkaliphile-based technology and has been emphasized.
... Aluminum alloys are widely used in the aviation and automotive industries, shipbuilding and instrumentation, rocket technology and construction [2], for example, aluminum alloys make up to 30 -35 % of aircraft materials. In modern aircraft, aluminum is used literally everywhere: in the fuselage, flaps, wing and tail structures, etc. [3]. ...
Article
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Despite being widely used in such industries as chemical, aviation and food ones, aluminum and its alloys are known to beprone to localized corrosion, and this remains a problem to be solved, especially when it comes to pitting corrosion. Therefore,there is a necessity to detect traces of corrosion at the earliest stages and to quantify the extent of corrosion damage. Thesimplest solution for assessing the overall corrosion rate is to use the gravimetric method, which, however, does not provideinformation for assessment of localized corrosion. This paper is devoted to the consideration of the possibilities of usingthe method of confocal laser scanning microscopy (CLSM) for assessing corrosion resistance using high-purity aluminum.The CLSM method, due to its high resolution (especially along the vertical axis), enables to obtain quantitative data on thevolume of corroded metal, determine the depth of corrosion damage including building their profilograms, and analyze themorphology of the surface damaged by corrosion. Owing to the high sensitivity of the CLSM method, corrosion losses weredetected within 21 days, contrary to the standard gravimetric method, which failed to determine the loss of metal even after160 days of corrosion testing
... Parmi les nombreux attributs et qualités expliquant sa popularité croissante, on cite sa malléabilité, sa résistance à l'oxydation et sa faible densité (Gourier-Fréry et Fréry, 2004). On le trouve sous forme combinée dans différents minéraux, principalement la bauxite (Gándara, 2013). Il est également utilisé dans l'industrie et se retrouve de ce fait dans les aliments, les produits cosmétiques, et même les médicaments (Exley et House, 2011). ...
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Omniprésent dans notre vie quotidienne, l’aluminium (Al) est l’un des éléments traces métalliques les plus dangereux pour la santé humaine. Nous y sommes exposés quotidiennement, par l’alimentation, l’application d’antitranspirants, l’utilisation d’antiacides, la vaccination, etc. L’exposition est donc inévitable, et chaque jour des taux modérés de ce métal pénètrent dans l’organisme et sont capables de s’accumuler dans certains organes. Malgré cela, la majorité de la population humaine n’est pas à risque évident de toxicité aluminique, puisque notre corps est équipé de plusieurs mécanismes qui ne permettent pas une absorption et une accumulation faciles, et facilitent son élimination. Par conséquent, une très faible quantité d’Al atteindra les différents organes et tissus (poumons, foie, cerveau, etc.). Une exposition élevée à l’Al entraîne des effets toxiques pulmonaires, gastro-intestinaux, cardiovasculaires, hématologiques, musculosquelettiques, neurologiques, hépatopancréatiques, etc. Les populations les plus exposées sont les patients dialysés, les consommateurs d’antiacides à long terme, et les professionnels de l’Al.
... Aluminium is among the most prevalent and widespread metals in our environment (Hardisson et al., 2017). It is widely used in commercial as well as domestic applications (kitchenware) Gándara, (2013). Humans are exposed to aluminium from various sources, such as diet, which accounts for 95% of body aluminium, drinking water, air, cosmetics, and medical drugs, primarily antacids (Skalny et al., 2021). ...
Article
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Neurodegeneration leads to the loss of structural and functioning components of neurons over time. Various studies have related neurodegeneration to a number of degenerative disorders. Neurological repercussions of neurodegeneration can have severe impacts on the physical and mental health of patients. In the recent past, various neurodegenerative ailments such as Alzheimer’s and Parkinson’s illnesses have received global consideration owing to their global occurrence. Environmental attributes have been regarded as the main contributors to neural dysfunction-related disorders. The majority of neurological diseases are mainly related to prenatal and postnatal exposure to industrially produced environmental toxins. Some neurotoxic metals, like lead (Pb), aluminium (Al), Mercury (Hg), manganese (Mn), cadmium (Cd), and arsenic (As), and also pesticides and metal-based nanoparticles, have been implicated in Parkinson’s and Alzheimer’s disease. The contaminants are known for their ability to produce senile or amyloid plaques and neurofibrillary tangles (NFTs), which are the key features of these neurological dysfunctions. Besides, solvent exposure is also a significant contributor to neurological diseases. This study recapitulates the role of environmental neurotoxins on neurodegeneration with special emphasis on major neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.
... Aluminum is the second most widely used metal in the world [64]. Hence, many researchers have paid a great deal of attention to optimizing its consumption for various purposes [65][66][67][68]. ...
Article
This study has two major aims, first, to compare the electrocoagulation (EC) system for Ni²⁺ removal from aqueous solution using direct current (DC) versus alternating current (AC), and second, to optimize the process for each type of current. For this purpose, four variables of current density, initial nickel concentration, initial pH of the solution, and reaction time, alongside three responses of remaining nickel, energy consumption, and electrode (aluminum) consumption, were considered. Accordingly, 30 experiments designed by the response surface methodology (RSM) based on the central composite design (CCD) were carried out for each mode. The statistical analysis revealed that the quadratic models proposed by the Design Expert are reliable to predict the outcomes. As quantitative results for the DC and AC modes, the average amount of the remaining nickel was 44.06 and 43.91 mg/L, energy consumption was 34.9 and 29.2 kWh/kg Ni removed, and electrode consumption was 2.3 and 1.2 kg Al/kg Ni removed, respectively. Thus, the transition from conventional DC to AC waveform coagulation led to a more than 16% reduction in energy consumption and approximately 47% depletion in electrode consumption.
... Aluminum, a corrosion-resistant metal, has light weight and density, high electrical and thermal conductivity, and high ductility and is easily deformable. For this reason, it is used in aerospace industries, transportation industries, packaging and food industries, building and construction, electrical industries, a wide range of home household and appliances, machinery and equipment, and monetary currency like aluminum coins [11,13]. ...
Article
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Aluminum poisoning has been reported in some parts of the world. It is one of the global health problems that affect many organs. Aluminum is widely used daily by humans and industries. Residues of aluminum compounds can be found in drinking water, food, air, medicine, deodorants, cosmetics, packaging, many appliances and equipment, buildings, transportation industries, and aerospace engineering. Exposure to high levels of aluminum compounds leads to aluminum poisoning. Aluminum poisoning has complex and multidimensional effects, such as disruption or inhibition of enzymes activities, changing protein synthesis, nucleic acid function, and cell membrane permeability, preventing DNA repair, altering the stability of DNA organization, inhibition of the protein phosphatase 2A (PP2A) activity, increasing reactive oxygen species (ROS) production, inducing oxidative stress, decreasing activity of antioxidant enzymes, altering cellular iron homeostasis, and changing NF-kB, p53, and JNK pathway leading to apoptosis. Aluminum poisoning can affect blood content, musculoskeletal system, kidney, liver, and respiratory and nervous system, and the extent of poisoning can be diagnosed by assaying aluminum compounds in blood, urine, hair, nails, and sweat. Chelator agents such as deferoxamine (DFO) are used in the case of aluminum poisoning. Besides, combination therapies are recommended.
... The TGA curve of HVOF thermal spray aluminium coated PBO fibres is shown in Figure 5. 15 ...
... Aluminum 7075-T6 has been chosen as the fixed material for the designated structure frames. This is because Aluminum 7075-T6 is said to be used where high strength is critical and where good corrosion resistance is not important [27]. ...
... The maximum load which can be applied for testing is determined by the elastic limit of the specimen under investigation. For instance, the elastic limit of the aluminium is 280 MPa [47]. Hence, the fabricated aluminium specimen is mechanically strained to the maximum tensile load of 160 MPa with the strain rate of 1 mm min −1 using a uniaxial tensile machine (UTM). ...
Article
In the background of designing a polymer nanocomposite based flexible strain sensors, homogenized dispersion of nanofillers remain challenging due to the trade-off between upholding of inherent characteristics of nanofillers and stable dispersion of nanofillers in the polymer matrix. This study provides an approach of balancing the stable dispersion of nanofillers and maintain the inherent characteristics of nanofibers by the method of polymer functionalization. Herein, two oppositely charged polymers polystyrene sulfonate sodium salt (PSS) and poly-diallyl-dimethyl-ammonium chloride (PDDA) are used separately to functionalize the multiwalled carbon nanotubes (CNT) and it dispersed in poly (vinylidene difluoride) (PVDF) polymer matrix to get flexible nanocomposite strain sensor to investigate both electrical conductivity and the gauge factor. PSS functionalized CNT (PSS-CNT) shows better dispersion than the PDDA-CNT in PVDF matrix. Besides, the electrical conductivity of PVDF/PSS-CNT (0.44 ± 0.02 Scm⁻¹) is about 28 times higher than the PVDF/PDDA-CNT, and the gauge factor of PVDF/PSS-CNT (9.8 ± 0.3) is 2-fold higher than the PVDF/PDDA-CNT. The stable dispersion of PSS-CNT is due to the repulsive nature existing between the individual CNTs caused by the attachment of charged polymer functional groups as same as intrinsic functional groups of the pristine CNT. This work signifies the role of synergy between the charged particles in the functional groups and charged nature of the filler influencing the performance of flexible strain sensors. The detailed investigation using various techniques reveals significance of selection of suitable polymers for functionalization by showing its influence in the context of designing the high-performance flexible strain sensor.
... Aluminum materials are resistant to corrosion caused by water and road salts, even if they are unpainted or uncoated. Aluminum is stainless and corrosion resistant, such as steel, if the paint is scratched or removed (Stojanovic et al. 2018;Gándara, 2013). ...
Conference Paper
Objective: In this study, it is aimed to evaluate the effect of the glass ceiling syndrome in female health care professionals on their organizational justice perception and to examine the factors affecting organizational justice perception and glass ceiling syndrome.
... Aluminum (Al) is widely used in the aerospace, architectural construction, and marine and chemical industries, as well as many domestic uses, because it is light, conductive, and corrosion-resistant metal [1]. Primary Al is produced from bauxite ore through Bayer's process; however, this method is not applicable in the processing of low-grade bauxite because of low alumina extraction and massive red mud production [2]. ...
Article
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Filamentous fungi have been proved to have a pronounced capability to recover metals from mineral ores. However, the metal recovery yield is reduced due to toxic effects triggered by various heavy metals present in the ore. The current study highlights the fungal adaptations to the toxic effects of metals at higher pulp densities for the enhanced bio-recovery of aluminum from low-grade bauxite. In the previous studies, a drastic decrease in the aluminum dissolution was observed when the bauxite pulp density was increased from 1 to 10% (w/v) due to the high metal toxicity and low tolerance of Aspergillus niger and Penicillium simplicissium to heavy metals. These fungi were adapted in order to increase heavy metal tolerance of these fungal strains and also to get maximum Al dissolution. A novel approach was employed for the adaptation of fungal strains using a liquid growth medium containing 5% bauxite pulp density supplemented with molasses as an energy source. The mycelia of adapted strains were harvested and subsequently cultured in a low-cost oat-agar medium. Batch experiments were performed to compare the aluminum leaching efficiencies in the direct one-step and the direct two-step bioleaching processes. FE-SEM analysis revealed the direct destructive and corrosive action by the bauxite-tolerant strains due to the extension and penetration of the vegetative mycelium filaments into the bauxite matrix. XRD analysis of the bioleached bauxite samples showed a considerable decline in oxide minerals such as corundum and gibbsite. Results showed a high amount of total Al (≥ 98%) was successfully bioleached and solubilized from low-grade bauxite by the adapted fungal strains grown in the presence of 5% pulp density and molasses as a low-cost substrate. Graphical abstract
... The TGA curve of HVOF thermal spray aluminium coated PBO fibres is shown in Figure 5. 15 ...
Article
This novel research work reports the possibility of using a high-performance polymer fiber as a potential reinforcement in a suitable metal matrix for the development of composites. The manufacturing route is an additive process using High-Velocity Oxy-Fuel Thermal-Spray technique. Continuous strands of Poly-benzobisoxazole and para-aramid were used as high-performance polymer reinforcement in a uni-directional configuration, and Zinc metal was used as matrix material. The developed Thermal-Spray composites were subjected to mechanical tensile test and characterized by Scanning Electron Microscopy and Optical Microscopy. The results of the tensile tests revealed a substantial increase in the tensile properties and the investigation of Scanning Electron Microscopy and optical images showed a good deposition of matrix material on the reinforcing polymer fibers. The testing and characterization results were conclusive of the fact that Poly-benzobisoxazole and para-aramid can be used as an effective reinforcement even at low volume content for high strength structural applications.
... Recycling does not degrade the aluminium properties since it has the same atom structure. Highly recyclable properties of aluminium make it a choice for sustainable material [7]. Fig. 1 shows how the aluminium is conserved and recycled. ...
Article
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Recycling of industrial waste is a subject of great importance today in any sector and more so in the aluminium industry. Aluminium recycling could sustain material resources, reduce the usage of energy, ease greenhouse gas emission and save the environment. This study examines the usage of direct hot extrusion of aluminium chip in the recycling of aluminium, focusing on the end product, properties and processing route. The process directly converts the new scrap of aluminium chips generated from industries to aluminium-based composite or aluminium alloys. The properties of the extrudates depend on the process parameters and the alloying elements added to the aluminium chips. High shear strain is required to disperse the oxide layer on the surfaces of the chip, thus permitting a contact between the newly exposed aluminium chips, and is consolidated to form a solid semi-finished product. The technique can be done through various process combinations and routes. The selection of process combination and routes depends on the product type and properties, degree of contamination of chip and size. The technique is proven as a viable method for aluminium recycling.
... Aluminum and its alloys have enormous applications in the automotive, electrical as well as in the aerospace industries [1,2]. Due to this, the surfaces of aluminum and its alloys are often exposed to reactive liquids and oils in various situations, which can induce surface tarnishing, corrosion and fouling thereby reducing their time-span of usefulness. ...
... Aluminium is the most abundant metal in the Earth's crust and the second most commonly used metal in the world. Because of its lightness, electrical conductivity and corrosion resistance, it is used in a variety of products, including vehicles, buildings, furniture, cans, electronic gadgets and many others (Freiría Gándara, 2013). The aluminium industry is among the highest energy intensive industries, with a consumption of around 4 % of the global electricity output (Tyabji and Nelson, 2012) and thus produces large amounts of greenhouse gas (GHG) emissions. ...
Article
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The aluminium industry is one of the largest emitters of greenhouse gases (GHG) and accounts for approximately 1 % of global GHG emissions. A large portion of emissions are indirect emissions, due to the large GHG footprint of consumed electricity, while direct energy and process-related emissions are also significant. The aluminium is widely used in packaging, transportation, the building sector and for various other purposes. This study focuses on aluminium slugs, which are semi products made from aluminium alloys and are used as tubes and containers in the pharmaceutical, food and cosmetic industries. Since the aluminium industry is among the largest GHG emitters, a Life Cycle Assessment (LCA) was performed to evaluate the environmental impact of aluminium slug production. Environmental impact assessment was performed using OpenLCA software, the Ecoinvent 3.1 database and self-collected plant data. The study includes the environmental impact of anode production, electrolysis and slug production. The functional unit for the study is 1 t of aluminium slug at the company exit gate. Besides GHG emissions and the related GHG footprint associated with slug production, acidification potential and photochemical oxidation potential are further assessed. Various opportunities for GHG emission reduction are further investigated in accordance with the longer-term company strategy. If more aluminium scrap were used and carbon capture performed, the GHG footprint could be reduced by 65 % compared to the base case.
... Metals such as steel represent an integral part of our lives in several areas in which they operate (Badr, 2009;Gándara, 2013). They are abundant, have excellent mechanical properties, easily recyclable and relatively low cost. ...
... 6 Chloride ions are greatly absorbed on the natural oxide film and cause deep ruptures into the surface. 7 The generation of these ruptures and the dissolution of the oxide phases disrupt the film continuity and cause the propagation of corrosion. To overcome the corrosion-related problems, the interaction of the surface and corrosive environment must be disconnected. ...
Article
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Micro-arc oxidation (MAO) is an attractive process for the fabrication of protective coatings on aluminum alloys used in many industrial applications, such as automotive, structural and aerospace. However, improvements in the corrosion resistance of aluminum alloys upon covering their surfaces with MAO coating may not be sufficient for extending the service life of the components utilized in harsh environments. In the present study, the MAO coating formed on a 6061 aluminum alloy was sealed using a stearic acid treatment. In the scope of the present study, the surface and cross-sectional microstructures and the phases of the MAO coatings were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, respectively. The wettability and surface roughness of the samples were measured by goniometer and profilometer, respectively. The corrosion resistance was assessed by long-term immersion in 3.5 % of mass fractions NaCl solution. Finally, it is concluded that sealing of the MAO coating by stearic acid treatment significantly improved the corrosion resistance of the 6061 quality aluminum alloy as compared to the untreated state and the unsealed MAO state.
... Protective layers based on silicide-aluminide phases prepared from the liquid phase were studied by various authors [1][2][3][4] and were shown to exhibit the potential of acting as protective layers where titanium and its alloys are used in high-temperature applications. [5][6][7][8][9][10][11][12][13] The principle of the method is based on the high affinity of silicon and aluminium to titanium. ...
Article
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The method of coating with silicon from the liquid phase (also called the hot-dip method) was presented by several authors who indicated that this was an effective and inexpensive technique capable of producing Ti-Al-Si layers on titanium. and titanium-alloy substrates that are rich in ternary phases. The present study examines the effects of the preparation conditions on the structure and properties of the layers. These layers provide excellent protection from high-temperature oxidation, even at a temperature of 950 degrees C. It was proved with SEM and X-ray analyses that the original tau(2) ternary phase almost completely decomposed into pure Ti5Si4 and TiSi silicides at the temperature of 950 degrees C. The formed layer, consisting of silicide sub-layers, exhibited superior protective properties in high-temperature applications.
... 9,10 The preparation of the bonding surfaces is of special importance since each type of surface impurities may disturb the required quality level of the joint. 11 Due to the tendencies of Al and Cu to oxidize under ambient conditions, [12][13][14] it is recommended that the cleaning of the contact surfaces of these metals should be performed immediately before the welding procedure. In addition to the superficial impurities, the quality of an Al/Cu joint may be affected by the impurities present in the volumes of Al and Cu, which, apart from affecting the conductivity of the basic materials, might also induce a production of various compounds at the very joint during the welding procedure, subsequently increasing the local contact resistance upon applying the Al/Cu bonding elements. ...
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... Protective layers based on silicide-aluminide phases prepared from the liquid phase method were studied by various authors [1][2][3][4] and have been demonstrated to possess the potential of acting as protective layers where titanium and its alloys serve in high-temperature applications [5][6][7][8][9][10][11][12][13]. The principle of the method is based on high affinity of silicon and aluminium to titanium. ...
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