High Aluminum Research Articles

Comparative Study of Life-Cycle Environmental and Cost Performance of Aluminium Alloy–Concrete Composite Columns

As is widely known, the construction industry is one of the sectors with a large contribution to global carbon emissions. Despite numerous efforts in the construction industry to develop low-carbon materials, there is a limited number of studies quantifying and presenting the overall environmental impact when these materials are applied in a construction project as structural members. To address this gap, this study focuses on assessing the life-cycle performance of novel structural aluminium alloy–concrete composite columns. In this paper, the environmental impacts and economic aspects of a concrete-filled aluminium alloy tubular (CFAT) column and a concrete-filled double-skin aluminium alloy tubular (CFDSAT) column were assessed using life-cycle assessment (LCA) and life-cycle cost analysis (LCCA) approaches, respectively. The cradle-to-grave system boundary is considered for these analyses to cover the entire life-cycle. A concrete-filled steel tubular (CFST) column is also assessed for reference. All columns are designed to have the same load-carrying capacity and, thus, are compared on a level-playing basis. A comparison is also made of the self-weight of these columns. In particular, the self-weight of the CFST column is reduced by around 17% when the steel tube is replaced by an aluminium alloy tube, and decreased by 47% when the double-skin technique is adopted in CFDSAT columns. The LCA results indicate that the CO2 emission of CFST and CFAT is almost the same, which is 21% less than the CFDSAT columns due to the use of high aluminium in the latter. The LCCA results show that the total life-cycle cost of CFAT and CFDSAT columns is around 29% and 14% lower, respectively, than that of the CFST column. Finally, a sensitivity analysis was carried out to evaluate the effects of data and assumptions on the life-cycle performance of the examined columns.

On-The-Flight trapping, LIBS analysis and discrimination of single meteorite particles generated by laser ablation

BackgroundThousands of micrometeorites fall to the Earth on a daily basis. Most of these meteorites have a rocky composition, but others are mainly composed of iron and nickel. Due to their small size, often ca. 100 μm in diameter, the process of searching for, collecting, and identifying these samples is remarkably tedious. In this work, we introduce a minimally invasive methodology for evaluating the full elemental composition of micrometeorites using optical emission spectroscopy of single particles produced by laser ablation of bulk targets. ResultsBulk meteorite samples were directly ablated within an ablation cell. From few micrograms of ablated matrix, we originated dry aerosols consisting of multielemental particles which were representative of the sample chemistry. SEM images confirmed that the generated particles exhibited spherical geometry. Particles were first optically trapped in air and, then, analyzed by laser-induced breakdown spectroscopy (LIBS). LIBS spectra evidenced compositional differences among samples. For example, Campo de Cielo meteorite featured a high iron content due to its metallic nature whereas LIBS results for Jbilet Winselwan and NWA 869 suggested that pyroxene components dominated the composition of the samples. In contrast, NWA 13739 and Vaca Muerta contained high aluminum intensity, thus indicating that the feldspathic component was dominant, as then verified by XRD. The intra-sample compositional variability were quite satisfactory, as revealed by the RSD data, below 45 %. For quantitative analysis, the percentages of FeO, SiO2, Al2O3, Na2O, MgO, TiO2, CaO, K2O, MnO, SrO, Cr2O3, and Li2O were calculated using CF-LIBS. SignificanceThis work demonstrates the applicability of laser excitation of individual particles in an optical trap for the multielemental analysis of meteorites. The methodology provides a complete overview of the samples, is capable of classificating them according to their main phases and yield preliminary quantitative information about those phases. Therefore, we present a minimally destructive pathway to be used as the first step in the inspection of these delicate samples. If the particles represent nanostructures inherent to the meteorites, it would constitute a major step in the analysis of extraterrestrial material that may provide fundamental insights into the structure and composition of the original materials at the microscale, a topic that remains an active area of research worldwide.

Dual‐Phase Enabled Sinusoidal Current Anodizing for Efficient Preparation of High Specific Capacitance Anode Aluminum Foils

The anodized aluminum oxide prepared by anodizing is the core of aluminum electrolytic capacitors, and its quality determines the performance of aluminum electrolytic capacitors. The traditional direct current (t‐DC) anodizing method commonly used in industrial production today with low current density has the problems of low anodizing efficiency, poor crystallinity, and high formation constants of the oxide film. However, high current density direct current anodizing has the problems of severe defects of the oxide film and much thermal dissolution of aluminum foil. Herein, the dual‐phase enabled sinusoidal current (DESC) anodizing method is proposed for the preparation of 200 V anodized aluminum foil with much higher efficiency and performance. After testing, it is found that the alumina prepared by the DESC method has higher crystallinity and fewer defects. Consequently, the specific capacitance of the DESC sample is 23% greater than that of the t‐DC anodized sample, while the former displays a lower loss angle tangent and leakage current. Meanwhile, DESC anodizing takes 60% time less than t‐DC anodizing due to its high current density. The DESC anodizing method has been identified as a promising avenue for further investigation, exhibiting high efficiency and performance.

Atomic doping of Alumina-based dielectric with high permittivity and breakdown field strength

High specific capacitance anode aluminum foils fabricated by introducing TiO2 to improve the permittivity (εr) of Al2O3 is one of the most effective ways to reduce the size and weight of aluminum electrolytic capacitors (AECs). However, the underlying mechanism by which the introduction of TiO2 causes capacity enhancement remains unclear. Here, a proposition is claimed that TiO2 is not directly responsible for the capacity enhancement but Al-doping TiO2 (AOT) actually. An atomically doping strategy based on atomic thermal diffusion and ionic electromigration is proposed to realize the fabrication of AOT via modulating the thermal and electric fields. Results show that the doping behavior of Al3+ induces the displacement of neighboring Ti4+ ions, which enhances the dipole polarization resulting in an increase of εr (25). Meanwhile, the diffusion of O2 and migration of O2– effectively removes the oxygen vacancy, enhancing the breakdown field strength (> 6 MV·cm−1) of dielectrics. Ultimately, the specific capacitance of anode foils is increased by about 50 % compared to those without AOT. On a brighter note, this work deepens the understanding of the capacity enhancement mechanism and will contribute to further facilitating the miniaturization of AECs.

Structural defect and activated alumina of spheric α-Al2O3 improving alumina ceramics density from the industrial coarse gibbsite

The quality of alumina ceramics generally depends on alumina powder. High-density alumina ceramics were prepared from industrial coarse gibbsite. Near-spheric α-Al2O3 with particles smaller than 500 nm was produced via the synergy of B and F from NH4BF4. The near-spheric α-Al2O3 calcined at low temperature generated alumina ceramics with high density and low porosity. Meanwhile, the wet pretreatment yielded smaller particles with structural distortion and high microstrain and aluminum hydroxide, notably increasing the relative density of alumina ceramics. 99.18% relative density, 0.017% porosity, and 27.54 GPa Vickers hardness of alumina ceramics were achieved at 1650°C for 2 h without additives and pressed sintering. In addition, the early stage of sintering of alumina green body followed particle boundary diffusion with reduced activation energy in the sintering process. The close packing of the spheric α-Al2O3, high microstrain of α-Al2O3, structural defects with considerable AlO4 units calcined at low temperature, structural distortion in the alumina, and activated alumina on the α-Al2O3 surface collectively promoted the densification of alumina ceramics, achieving remarkable hardness, high density, and tiny porosity.

Advancing energy recovery ventilators with phase change materials for cooling load reduction and heat exchange efficiency improvement

Efforts to reduce building energy emissions and achieve net-zero carbon scenarios globally have increasingly focused the building sector on improving energy efficiency. Heating, ventilation, and air conditioning (HVAC) systems play a vital role in providing comfortable indoor environments but significantly contribute to energy consumption and greenhouse gas emissions. Energy recovery ventilators are efficient active systems that prevent unnecessary indoor heat loss and gain, regardless of outdoor climate, making them excellent technologies for achieving zero energy. In a hot and humid summer climate, such as in Korea, it is crucial to enhance the efficiency of energy recovery ventilators and reduce cooling energy consumption. A Green HVAC design aimed at reducing the energy consumption of active systems to near zero was proposed by applying phase change material-based modules with high heat storage performance to energy recovery ventilators. The phase change material module is stabilized with high thermal conductivity aluminum packing and is configured as a mesh-type structure to amplify heat exchange efficiency with air. Compared to the energy recovery ventilator, the application of the module demonstrated a reduction in supply air temperature by an average of 2.6 °C in high-temperature outdoor. During the effective operating period, a continuous indoor intake temperature reduction effect was observed, and the sensible heat exchange efficiency showed a 21.32 % improvement with the module using n-octadecane. Phase change material modules that can enhance ventilation and improve energy efficiency in high-temperature environments can be proposed as a technology to achieve Green HVAC.

Structure and Properties of Aluminoborosilicate Glasses for OLED Display Substrate

The effects of Al2O3/SiO2 and B2O3/SiO2 substitution on the network structure and properties of high aluminium and low boron alkali-free aluminoborosilicate glasses used as OLED display glass substrate were investigated. A more polymerized network within 3 mol.% substitution for Al2O3/SiO2 was obtained, represented by the decreasing value of NBO/T from 0.14 to 0.08, as well as the opposite result for B2O3/SiO2 substitution. Q3 and Q4 units held the vast majority of Si groups, and the tetrahedral [AlO4] occupied the majority among Al groups, while [AlO5] and [AlO6] was too low or even too tiny to be detected obviously in the investigated glass system. [BO4] concentration decreased from 59.04% to 52.74% with the increase of B2O3 content, and [BO3] increased accordingly, which indicated that [BO4] was not the preferential borate group in this glass system even if (RO-Al2O3)/B2O3 > 1. Higher [BO3] at lower (RO-Al2O3)/B2O3 value (>1) indicated the low conversion efficiency from [BO3] to [BO4] in the investigated glasses. The glass network between the bulk sample and glass melt was also investigated, and some differences in Al groups could be concluded from the test of the glass melt. Finally, samples with satisfied properties for OLED display substrate were acquired.

High Aluminum content in the aquifer of Camaçari industrial pole, state of Bahia, Brazil: Correlation with natural and anthropogenic environmental factors using multivariable analysis

<p class="MsoNormal">This work used multivariable analysis to correlate groundwater high aluminum content in the area of the Liquid Effluent Treatment Center—CETREL of the Camaçari Industrial Pole, with natural environmental factors: geology, hydrogeology, precipitation, soil and vegetation; and anthropic: equipments of treatment and disposal of industrial waste from CETREL. This company made available data from 99 monitoring wells, period 2006–2016, with aluminum content above (0.2mg/L) the limit established by the Ministry of Health Ordinance Nº 888, 5 April 2021. Previous studies have indicated that there is no correlation of aluminum in groundwater of the Camaçari Industrial Pole with other metallic contaminants; also, that aluminum in the studied region is disseminated in the geological matrix, clayey soils, and poor and leached Cerrado soils. The Kruskal-Wallis test indicated significant correlation of high aluminum content with the treatment/disposal areas, geology, soil and vegetation; and no correlation with precipitation and hydrogeology. The four environmental factors indicating the highest average aluminum content (±C<sub>95%</sub>), in descending order, are: Clayey Soils, Organic Sludge Farm I, Marizal Formation, and Herbaceous-Subshrub Vegetation. The multivariable analysis indicated that, the most influential factors on the high aluminum content in groundwater of the CETREL region, are all ultimately associated with the leaching of aluminum present in the solid matrix. As CETREL processes are not correlated with aluminum residues, the results were an important information for the company environmental managers.</p>

High Aluminum content in the aquifer of Camaçari industrial pole, state of Bahia, Brazil: Correlation with natural and anthropogenic environmental factors using multivariable analysis

<p class="MsoNormal">This work used multivariable analysis to correlate groundwater high aluminum content in the area of the Liquid Effluent Treatment Center—CETREL of the Camaçari Industrial Pole, with natural environmental factors: geology, hydrogeology, precipitation, soil and vegetation; and anthropic: equipments of treatment and disposal of industrial waste from CETREL. This company made available data from 99 monitoring wells, period 2006–2016, with aluminum content above (0.2mg/L) the limit established by the Ministry of Health Ordinance Nº 888, 5 April 2021. Previous studies have indicated that there is no correlation of aluminum in groundwater of the Camaçari Industrial Pole with other metallic contaminants; also, that aluminum in the studied region is disseminated in the geological matrix, clayey soils, and poor and leached Cerrado soils. The Kruskal-Wallis test indicated significant correlation of high aluminum content with the treatment/disposal areas, geology, soil and vegetation; and no correlation with precipitation and hydrogeology. The four environmental factors indicating the highest average aluminum content (±C<sub>95%</sub>), in descending order, are: Clayey Soils, Organic Sludge Farm I, Marizal Formation, and Herbaceous-Subshrub Vegetation. The multivariable analysis indicated that, the most influential factors on the high aluminum content in groundwater of the CETREL region, are all ultimately associated with the leaching of aluminum present in the solid matrix. As CETREL processes are not correlated with aluminum residues, the results were an important information for the company environmental managers.</p>

Enhanced phosphorus adsorption using modified drinking water treatment residues: A comparative analysis of powder and alginate bead forms

This study provides an analysis of the phosphorus adsorption efficacy of three modified drinking water treatment residues (MDWTRs): MDWTR-P (powdered form), MDWTR-D2, and MDWTR-D5 (alginate bead-entrapped forms with bead diameters of 2 mm and 5 mm, respectively). The preparation process involved washing and drying the drinking water treatment residue, followed by grinding and sieving to achieve particle sizes below 90 μm. The residue was then incinerated at 600 °C in oxygen-limited conditions. Subsequently, the MDWTR was formulated into alginate beads by mixing with sodium alginate and FeCl3 solutions, resulting in spherical particles of specified diameters. The evaluation of surface area, pore volume, pore size, and CHN concentration revealed that MDWTR-D5 possesses the largest surface area (284.7 m2 g−1) and highest micropore volume (0.04 cm3 g−1), indicating a greater capacity for adsorption. SEM-EDS analysis demonstrated significant compositional changes post-treatment, particularly elevated phosphorus levels, confirming effective adsorption. Metal content analysis indicated high aluminum levels in MDWTR-P and increased iron content in MDWTR-D5. Toxicity Characteristic Leaching Procedure (TCLP) and in vitro bioaccessibility (IVBA) tests confirmed the non-hazardous nature of all MDWTRs, ensuring their safety for environmental applications. Kinetic analyses using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models highlighted the superior performance of MDWTR-D5, with the highest equilibrium adsorption capacity and initial adsorption rate across all tested concentrations, suggesting both high efficiency and rapid adsorption potential. Further validation using Langmuir and Freundlich isotherms revealed MDWTR-D5's highest monolayer adsorption capacity (22.88 mg g−1) and Freundlich adsorption capacity parameter (6.97 mg g−1). Statistical analysis via one-way ANOVA confirmed significant differences in phosphorus concentrations among the MDWTRs samples (p-value <0.001), consistently underscoring MDWTR-D5's superior adsorption performance. These findings highlight MDWTR-D5's potential as an effective adsorbent for phosphorus removal in wastewater treatment, emphasizing its applicability in environmental remediation strategies.

Revealing the environmental-assisted degeneration mechanism of an Al-containing dual-phase high entropy alloy in supercritical water

A dual-phase high entropy alloy (DP-HEA) containing 7.82 wt% Al was synthesized to withstand corrosive supercritical water. The long-term corrosion and quasi-static tensile tests reveal superior resistance to such environmental-assisted degeneration. The outstanding corrosion resistance can be attributed to the high aluminum content in B2 phase, which forms a continuous Al2O3 layer for protection, while the FCC phase is selectively corroded. Under external stress, stress corrosion cracking (SCC) initiates from surface oxide and penetrates uncompact mixed Cr/Al-rich oxide in deteriorated FCC regions or corroded phase interface, though network-shaped B2 can inhibit SCC propagation, which supports the brittle film rupture model.

The Impact of Welding Parameters on the Welding Strength of High Borosilicate Glass and Aluminum Alloy

This study adopts a new surface pretreatment method, Laser Surface Remelting (LSR). This experiment aims to establish a set of laser welding process parameters suitable for aluminum alloy and glass under this specific pretreatment. This experiment explores the impact of laser welding parameters on the welding strength between high borosilicate glass and aluminum alloy. The study specifically investigates the effects of four process parameters: defocus amount, laser power, frequency, and pulse width on the welding outcome. The results indicate that the welding quality between the aluminum alloy and glass reaches its optimum when the defocus amount is zero (i.e., when the laser converges at the interface between the glass and the metal) and the laser welding parameters are set to a power of 250 W, a welding speed of 1 mm/s, a welding frequency of 10 Hz, and a pulse width of 2.5 ms. The experiment also analyzes the fracture morphology under different parameters, summarizing the locations and causes of fractures, and establishing the relationship between the fracture location and the welding strength.

Damage and Recovery Behavior of Low-Replacement-Rate Fly Ash Concrete after Different High-Temperature Exposures.

This study focuses on investigating the strength recovery of fire-damaged fly ash concrete (FAC) with a low substitution rate of 10% through post-fire curing. The chemical and microstructural changes were analyzed using X-ray diffraction (XRD), derivative thermogravimetry (DTG), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), and nitrogen adsorption. The findings indicate that the incorporation of fly ash slightly enhanced the strength after exposure to 400 °C; this was attributed to improved pozzolanic reactions, which were not observed at higher temperatures of 600 °C and 800 °C. Moreover, a positive effect on the recovery of compressive strength was observed due to the pozzolanic reaction. However, due to the relatively low fly ash content, depletion occurred at a later age, resulting in the inability to inhibit microstructural damage caused by the production of portlandite, thereby weakening the compressive strength. Interestingly, fly ash influenced the morphology of calcium carbonate and calcium silicate hydrate crystals, which is potentially ascribed to the role of high aluminum content acting as a crystallization-guiding agent.

Intercalation of Al3+ into Prussian Blue Analogues from Nonaqueous Electrolytes.

Nonaqueous aluminum-ion batteries (AIBs) provide advantages, such as high energy density, enhanced safety, and reduced corrosion, making them ideal for advanced energy storage solutions. A key challenge faced by AIBs is the lack of suitable cathode materials for rapid Al-ion insertion /extraction. Herein, K2Mn[Fe(CN)6] 2H2O (KMHCF) is innovatively chosen as a model to investigate the aluminum storage performance of Prussian blue analogues in nonaqueous AIBs. As anticipated, the KMHCF allows for reversible aluminum storage and exhibits characteristic charge/discharge plateaus. Furthermore, carbon combined highly crystalline KMHCF (HC-KMHCF@C) is synthesized through a chelator-assisted preparation method in combination with an in situ carbon compositing technique. With reduced [Fe(CN)6]4⁻ defects, lower interstitial water content, and enhanced conductivity, HC-KMHCF@C exhibits a high aluminum storage capacity (146.2 mAh g⁻¹ at 0.5 A g⁻¹) and satisfactory cycling performance (maintaining 86.4 mAh g⁻¹ after 800 cycles). The electrochemical reaction mechanism of HC-KMHCF@C is investigated in detail. During the initial charge, K⁺ ions are extracted, shifting the structure from monoclinic to cubic. In subsequent cycles, reversible Al3+ insertion and extraction cause the structure to alternate between monoclinic and cubic phases.

High aluminum removal efficiency by the two green microalgae, Scenedesmus sp., and Nannochloropsis sp., under laboratory conditions

Heavy metal contamination, such as aluminum (Al), is a significant global environmental concern. In addressing this issue, the ecologically-friendly method of phytoremediation using microalgae has been gaining attention. Our study explored the Al uptake capabilities of two green microalgae species, Scenedesmus sp. and Nannochloropsis sp., under laboratory conditions. Both species were exposed to varying Al concentrations (0.5, 1, and 2 mg L−1) to evaluate their growth and tolerance levels over two weeks. Results showed that Scenedesmus sp. not only demonstrated tolerance to Al up to 2 mg L−1 but also had an enhanced growth rate at the 2 mg L−1 concentration during the 8–14 day period. On the contrary, Nannochloropsis sp. displayed a reduced growth rate at 2 mg L−1 of Al concentration. Both species showed an Al removal efficiency of up to 98–99.7 %. The removal efficiency of two algae was abundance-independent in the present study. Our findings indicated that both microalgae species offer great potential for treating Al-contaminated water, with Scenedesmus sp. standing out for tolerance and removal efficiency, while Nannochloropsis sp. excels in absorbing Al at lower concentrations.

Physiological Responses of Crotalaria spp. to the Presence of High Aluminum Availability in the Soil.

Brazilian soils are predominantly rich in aluminum, which becomes mobile at pH < 5, affecting sensitive plants; however, some species have developed aluminum tolerance mechanisms. The purpose of this study was to compare the physiological responses of Crotalaria genus species, family Fabaceae, which have the ability to associate with nitrogen-fixing bacteria under the influence of Al3+ in the soil. The soil used was Oxisol; the experimental design was in randomized blocks in a factorial scheme (2 × 3): soil factor (available toxic aluminum content; correction of dolomitic limestone-MgCO3) and species factor (C. juncea; C. spectabilis; C. ochroleuca); cultivated within 43, 53, and 53 days, respectively, with five replications; 30 experimental samples. Mass and length, pigments, gas exchange, and changes in nitrogen metabolism were evaluated. C. juncea showed a higher concentration of amino acids in the leaves, internal carbon, and stomatal conductance in soil with Al3+, as well as higher production of ureides, allantoinic acid, allantoic acid, proteins, and amino acids in the nodules, with 78% of the Al3+ accumulation occurring in the roots. C. ochroleuca demonstrated greater shoot length and nodule number production in limed soil; in soil with Al3+, it showed a 91% increase in chlorophyll a content and 93% in carotenoids. C. spectabilis showed a 93% increase in ureide production in the leaves in soil with Al3+.

Species assemblages and their drivers differ between trees and lianas in a seasonal evergreen forest in Thailand

AbstractDespite a long tradition in ecology of studying tree species assembly and its potential drivers in tropical forest communities, little information exists with respect to lianas (woody climbers), the second most abundant life form of woody plants in tropical forests. Lianas influence forest diversity and stability and provide critical resources for forest fauna. Using a unique dataset of a 30‐ha plot in Thailand, where tree and liana individuals were fully mapped, we investigated the degree to which local species assemblages of trees and lianas of different size classes (i.e., seedlings, established individuals, and large individuals) are related to local environmental conditions. We asked (1) What are the spatial patterns and environmental drivers of local tree and liana species assemblages? (2) How do such patterns and drivers differ among size classes? (3) Which species associate with these assemblages? Local assemblages of established trees showed substantial structuring by environmental variables, whereas we found only weakly structured assemblages of tree seedlings, large trees, and lianas of all size classes. Our results indicated that the biotic and abiotic drivers of local species assemblages differed strongly between tree and liana communities and across size classes. Species assemblages of trees were mainly driven by soil nutrients, leading to patchy assemblages associated with high base saturation (Alfisols) and assemblages associated with lower levels of base saturation and higher aluminum (Ultisols), whereas tree seedling assemblages were only weakly structured by riparian zones. In contrast, species assemblages of established and large lianas were primarily associated with forest canopy structure, separating low‐canopy forests from high‐canopy forests, whereas soil nutrients were the only factors associated with liana seedling assemblages. The weak environmental structuring of tree seedlings and large trees suggests that other mechanisms, such as stochastic disturbances, competition for space, or animal seed dispersal, may play an important role in structuring tree communities in this seasonal tropical forest. The weak patterns observed in liana communities across all life stages raise questions about the underlying mechanisms of liana community assembly, and further research should focus on liana niches, their dispersal mechanisms, and host tree relations.

Observation of Initial Interfacial Reaction between High Aluminum Molten Steel and CaO–Al2O3 Inclusion at 1873 K Using Laser Confocal Scanning Microscopy and Micro‐Computerized Tomography

Observation of Initial Interfacial Reaction between High Aluminum Molten Steel and CaO–Al₂O₃ Inclusion at 1873 K Using Laser Confocal Scanning Microscopy and Micro‐Computerized Tomography

Al nanowire-embedded silicon for broadband optical modulation: Forming mechanism and optical performance

In recent decades, silicon has been widely used in light regulation devices, owing to its wideband high refractive index and low dispersion. To meet the increasing demands for various applications, optical modulation techniques appear of great potential to enhance the optical performance of Si-based devices. However, challenges still remain in achieving precise control over the band structure and resonance modes without introducing complex artificial structures. In this study, a composite film composed of silicon embedded with high fraction aluminum nanowires was developed by magnetron sputtering. It was revealed that the formation of aluminum nanowires was attributed to the spontaneous phase separation between silicon and aluminum, which was strongly dependent on the filling fraction and surface diffusion length of the aluminum during the co-sputtering process. The composite microstructure was precisely regulated by manipulating adatom diffusion and reevaporation through ion bombardment, thereby modifying its broadband optical properties. Moreover, exceptional electromagnetic properties were achieved by incorporating aluminum nanowires into silicon, as evidenced by the metallic behaviors in the short-wavelength regime and dielectric properties in the infrared spectrum range.

Study on the Aging Precipitation Behavior and Kinetics of Al-10.0Zn-3.0Mg-2.8Cu Alloy by Pre-Deformation Treatment.

In this paper, the effect of thermomechanical treatment process on the hardening behavior, grain microstructure, precipitated phase, and tensile mechanical properties of the new high-strength and high-ductility Al-10.0Zn-3.0Mg-2.8Cu alloy was studied, and the optimal thermomechanical treatment process was established. The strengthening and toughening mechanisms were revealed, which provided technical and theoretical guidance for the engineering application of this kind of high strength-ductility aluminum alloy. Al-10.0Zn-3.0Mg-2.8Cu alloy cylindrical parts with external longitudinal reinforcement were prepared by a composite extrusion deformation process (reciprocal upsetting + counter-extrusion) with a true strain up to 2.56, and the organizational evolution of the alloys during the extrusion deformation process and the influence of pre-stretching treatments on the subsequent aging precipitation behaviors and mechanical properties were investigated. The results show that firstly, the large plastic deformation promotes the fragmentation of coarse insoluble phases and the occurrence of dynamic recrystallization, which results in the elongation of the grains along the extrusion direction, and the volume fraction of recrystallization reaches 42.4%. Secondly, the kinetic study showed that the decrease in the activation energy of precipitation increased the nucleation sites, which further promoted the diffuse distribution of the second phase in the alloy and a higher number of nucleation sites, while limiting the coarsening of the precipitated phase. When the amount of pre-deformation was increased from 0% to 2%, the size of the matrix precipitated phase decreased from 5.11 μm to 4.1 μm, and when the amount of pre-deformation was increased from 2% to 7%, the coarsening of the matrix precipitated phase took place, and the size of the phase increased from 4.1 μm to 7.24 μm. The finalized heat treatment process for the deformation of the aluminum alloy tailframe was as follows: solution (475 °C/3 h) + 2% pre-stretching + aging (120 °C/24 h), at which the comprehensive performance of the alloy was optimized, with a tensile strength of 634.2 MPa, a yield strength of 571.0 MPa, and an elongation of 15.2%. The alloy was strengthened by both precipitation strengthening and dislocation strengthening. After 2% pre-stretching, the fracture surface starts to be dominated by dense tough nest structure, and most of them are small tough nests, and small and dense tough nests are the main reason for the increase in alloy toughness after 2% pre-stretching deformation.