Search Results (547)

This study systematically investigates the synergistic effects of the pre-stretching deformation and aging temperature on the precipitation behavior and mechanical properties of an Al-Cu-Li alloy. The results indicate that increasing the pre-stretching deformation significantly refines and increases the number density of T₁ and θ′ phases while optimizing the grain boundary precipitate morphology, thereby enhancing the fracture toughness and fatigue resistance without compromising the high strength. In contrast, elevating the aging temperature promotes the coarsening of the T₁ phase, inhibits θ′ precipitation, and coarsens the grain boundary precipitates, leading to a deteriorated damage tolerance. By matching 3.5~4.5% pre-stretching with 145~155 °C aging, a synergistic optimization of ultra-high strength and damage tolerance can be achieved. Full article

Thin wall composite fan blades in aircraft engines demand designs that ensure structural integrity under operational loads while resisting foreign object damage and bird strikes. This study presents a finite element investigation of thin wall composite blades with metal leading edge caps, modeled through parametric coupon analyses under static flexure loading using ANSYS APDL. Three metallic leading edge caps, Ti-6Al-4V, Inconel 718, and 15-5 PH stainless steel, were combined with IM7/8551-7 carbon fiber composites. Parametric variations included changes in metal cap material, geometric designs of the joint, and other things. Performance was evaluated in terms of failure stress, interlaminar shear strains, interface integrity, and failure margins. Results reveal that cap design and cap material critically govern structural response, with distinct interchanges between strength-to-weight efficiency, interface stresses, and interlaminar shear strain. Optimal designs reduced interlaminar shear strain levels in thin wall composite blades, while retaining adequate stiffness and strength. The results underscore the importance of interface design for effective load transfer and provide design guidelines for lightweight, damage-tolerant thin wall composite fan blade structures. Full article

Laser powder bed fusion (LPBF) of AA7075 is severely constrained by a narrow process window and susceptibility to defect formation (hot cracking and porosity), which often dominates performance. In this study, 5 wt.% AlCoCrFeNi_2.1 high-entropy alloy (HEA) particles, volumetric energy density (VED = 74–222 J·mm⁻³), and subsequent T6 heat treatment were systematically investigated to reveal their combined effects on defect structure, crystallographic texture/substructure, and tensile behaviour. Quantitative EBSD shows a measurable grain refinement in the as-built state (average grain size 13.44 → 11.80 µm, ~12%) accompanied by a pronounced weakening of the <001> fibre texture (maximum MRD 4.94 → 2.38), indicating disrupted epitaxial growth and a more dispersed orientation distribution. After T6, the reinforced alloy retains a higher low-angle boundary fraction (31.62% vs. 24.17% in unreinforced AA7075) and a higher kernel average misorientation (0.80° vs. 0.60°), consistent with particle-stabilised substructure retention and retarded recovery. Across all VEDs, AA7075-HEA exhibits higher microhardness (compared with AA7075, the addition of HEA increases the hardness by roughly 20–50 HV) and tensile strength, with the intermediate VED (140.74 J·mm⁻³, T6 states) yielding the best performance. While macroscopic cracking is not fully eliminated, the results clarify that HEA-enabled texture/substructure modifications can contribute to enhanced defect tolerance and are more effectively translated into tensile performance when the as-built defect severity is controlled. These findings provide quantitative insights into defect–microstructure–property coupling in LPBF AA7075-HEA composites from as-built to T6 states. Full article

To address the challenge of controlling Fe impurity content during the recycling of aluminum alloys, this study utilized commercial 5083 aluminum alloy as a matrix to prepare alloy samples with four different Fe contents via smelting. The effects of Fe content on the microstructure, mechanical properties, and corrosion resistance of the as-cast 5083 aluminum alloy were systematically investigated. The results indicate that increasing the Fe content induces a significant morphological evolution of the Fe-rich phases, transitioning from compact Chinese-script α-Al(Fe,Mn)Si phases at low Fe levels to coarse needle-like β-AlFeSi phases. Concurrently, both the quantity and size of the second phases increase significantly. Mechanical testing reveals that the hardness of the alloy gradually rises from 67 HV to 72 HV due to second-phase strengthening. The tensile strength shows a trend of initially increasing and then decreasing, peaking at 0.45 wt.% Fe; however, excessive Fe leads to the formation of needle-like phases that cause stress concentration, resulting in a decline in tensile strength. The elongation decreases gradually with increasing Fe content, with a maximum reduction of 19.7%. Electrochemical tests show that higher Fe content increases the self-corrosion current density and decreases the capacitive loop radius, indicating a significant degradation in the alloy’s corrosion resistance. This work provides an experimental basis for the tolerance control of Fe impurities and the performance optimization of recycled 5083 aluminum alloys. Full article

The 2011 Fukushima accident highlighted the vulnerability of traditional Zr alloy fuel cladding under loss-of-coolant accident (LOCA) conditions, prompting the development of accident-tolerant fuel (ATF) systems. A promising near-term solution involves depositing protective coatings on existing Zr alloy cladding. Among various deposition techniques, cold spray technology has emerged as one of the leading methods due to its solid-state, low-temperature process, which minimises thermal degradation and allows for the deposition of a wide range of high-performance materials. This review provides a comprehensive examination of recent advances in cold-sprayed coatings for ATF cladding, beginning with an overview of the fundamentals of cold spray technology and its specific advantages for nuclear applications. The core of the review critically analyses three primary coating systems: Cr, FeCrAl alloys, and MAX phase composites, with a particular focus on Cr coatings, as they have been more extensively studied compared to the other two material systems. Key coating properties, including microstructure of the coating-substrate interface, mechanical properties, thermal conductivity, oxidation resistance, irradiation tolerance, and performance under normal operation and simulated LOCA conditions, are discussed in detail, with particular emphasis on the potential of cold-sprayed Cr coatings to enhance Zr alloy cladding. Cr coatings demonstrate significant improvements in oxidation resistance and irradiation stability, but also face challenges such as high-temperature interfacial reactions. To address these issues, promising solutions, such as diffusion-barrier bilayer systems, are being explored. Additionally, the review discusses FeCrAl and MAX phase composite coatings, highlighting their promising long-term performance under extreme conditions. The review concludes with recommendations for further research to optimise cold spray processes and ensure the robustness of coatings in operational reactor environments. Full article

High-entropy alloy (HEA) multilayers represent a promising class of advanced coating materials due to their superior mechanical properties, corrosion resistance, and irradiation tolerance. However, the specific role of interface coherency on the creep behavior of HEA multilayers remains unclear. In this work, FCC/BCC Al-Cr-Fe-Ni HEA multilayers with different coherency were prepared by precisely controlling the modulated period (λ) via RF magnetron sputtering. Their room-temperature creep properties were systematically investigated through nanoindentation under different loading rates. The results reveal a strong dependence of creep resistance and deformation mechanisms on the interface coherency. HEA multilayers with semicoherent interfaces (λ = 16 nm) exhibit the highest creep resistance, where creep is primarily mediated by atomic diffusion or interface slip. In contrast, samples dominated by coherent interfaces or grain boundaries (λ = 8, 32, and 80 nm) demonstrate dislocation slip-dominated creep. This work elucidates how interfacial coherency dictates the transition between diffusion-mediated and dislocation-mediated creep mechanisms in HEA multilayers, providing critical insights for the design of next-generation creep-resistant nanostructured coatings. Full article

High-entropy amorphous materials are attracting increasing attention due to their excellent corrosion resistance and radiation tolerance in nuclear environments. In this study, novel Al₂Cr₁₆Fe₅₀V₂₀Ti₁₂ high-entropy alloy (HEA) coatings with thicknesses of 900 nm and 1400 nm were synthesized via magnetron sputtering and systematically evaluated for their structural, electrochemical, and mechanical performance. X-ray diffraction confirmed the amorphous nature of the coatings, while scanning electron microscopy revealed a denser, defect-free, and more uniform morphology in the thicker coating. Electrochemical testing in a 3.5 wt.% NaCl solution demonstrated a tenfold reduction in corrosion current density and nearly a twofold increase in charge transfer resistance for the 1400 nm coating, attributed to its improved passive film stability. Finite element modeling validated the experimental load–displacement behavior and revealed well-confined and uniformly distributed stress and strain fields within the coating. These findings establish the 1400 nm Al₂Cr₁₆Fe₅₀V₂₀Ti₁₂ coating as a promising candidate for protective applications in chloride-rich and radiation-intense nuclear systems. Full article

Erbium-165 (¹⁶⁵Er) is an Auger electron emitter with 7.2 electrons per decay and very few other emissions, making it an interesting candidate for Auger electron therapy. We present here a procedure for producing ¹⁶⁵Er by the ^natHo(p,n)¹⁶⁵Er nuclear reaction on a 16.5 MeV medical cyclotron. The target was prepared by pressing a Ho₂O₃:Al 1:1 (w/w) powder mixture on a Ag disc with a cylindrical depression in the center. With a 0.1 mm Nb foil in front, degrading the energy to 15 MeV, and water cooling at the back of the Ag disc, the target could withstand irradiation at currents up to 45 µA without showing any signs of damage. The beam tolerance of the target was also estimated by calculating the temperature and heat dissipation in the target via the numerical solution of the heat transport equations. For a 180 mg target, the production yield was 12.3 ± 1.9 MBq/µAh. The separation of two neighboring lanthanides is challenging, which led us to study the distribution coefficients for Er and Ho on commercially available LN2 resin for both HNO₃ and HCl eluents. Based on these values, we propose a purification procedure involving two successive LN2 columns for separating the ¹⁶⁵Er from Ho and Al, followed by a small TK221 column to concentrate the final eluate. No radionuclidic impurities were detected, and the chemical impurities found in the final formulation were traces of Ho, Er, Ca, Pb, and Fe. For three different chelators (DOTA, DTPA, and CHX-A″-DTPA), the effective molar activity of the final formulation was measured. The stability of the three complexes formed was also assessed upon incubation in mouse serum for 28 h. Full article

This study investigates the irradiation response of two L1₂-strengthened HEAs, (Ni₂Co₂FeCr)₉₂Ti₄Al₄ (TiHEA) and (Ni₂Co₂FeCr)₉₂Nb₄Al₄ (NbHEA), subjected to 6.4 MeV Fe³⁺ irradiation at 500 °C up to 30 dpa. Transmission electron microscopy (TEM) and atom probe tomography (APT) consistently showed that the Ti-containing HEA maintains L1_2-ordered structure and compositional stability better than Nb-containing alloys under irradiation. This difference is attributed to the distinct solute–defect interactions. Ti imposes a weaker hindering effect on vacancy mobility, allowing vacancies to remain mobile and participate in thermal reordering processes that counteract ballistic mixing, whereas Nb acts as a strong vacancy trap, suppressing the diffusion required for structural recovery. Irradiation-induced dislocation loops in the two alloys further exhibited different characteristics. TiHEA showed larger loops at lower number density, and NbHEA exhibited a higher density of smaller loops, consistent with their respective stacking fault energies and loop mobility. Nanoindentation results indicated that TiHEA exhibited a slightly higher irradiation hardening rate (27%) than NbHEA (23%), likely associated with a stronger order-strengthening contribution, given the better preservation of precipitate order in TiHEA under irradiation. These findings show the critical role of solute addition in designing radiation-tolerant high-entropy alloys. Full article

Maintaining a consistent quality of TiAl4822 blades used in jet engines is crucial, even when compositional variations occur during production. This study investigates the optimal Al and O concentration ranges that yield favorable practical properties. Additionally, the feasibility of reusing machining chips as a low-cost melting feedstock is explored. The results indicate that both impact resistance at 25 °C and machinability remain unaffected or even improve at O concentrations up to at least 0.13 wt%. Moreover, materials containing 0.13 wt% O exhibit the widest optimal range of Al concentrations (46.8–47.4 at%), but was narrower at lower or higher Al concentrations. The influence of the α₂-phase ratio on impact resistance is substantially greater than that of O concentration, with the optimal range being 0.2–0.3. Furthermore, a new pre-treatment method is developed to reuse machining chips containing large amounts of water-soluble cutting oil. This method involves removing C through atmospheric heating after ultrasonic cleaning using acetone. Furthermore, TiAl4822 castings including these preprocessed chips exhibit superior properties compared with those of chip-free low-O materials, despite the higher O concentration. These findings demonstrate that moderate O enrichment is tolerable, and even beneficial, enabling cost-effective recycling in TiAl4822 blade production. Full article

Soil salinization is one of the main factors limiting agricultural productivity, negatively affecting seed germination and initial growth of maize (Zea mays L.). As a sustainable alternative, seaweed-based biostimulants, especially extracts of Ascophyllum nodosum, have stood out in mitigating abiotic stresses. This study aimed to evaluate the potential of A. nodosum extract in inducing tolerance to saline stress in maize seeds of the AL Bandeirante cultivar. To this end, three independent bioassays were conducted under controlled conditions: (i) evaluation of five doses of the extract (0; 0.5; 1.0; 1.5 and 2.0 mL L⁻¹); (ii) effects of five osmotic potentials induced by NaCl (0, −0.2, −0.4, −0.6 and −0.8 MPa); and (iii) the interaction between the most efficient doses and salinity levels, comparing the extract to its mineral fraction. Seed germination, percentage of normal and abnormal seedlings, radicle and epicotyl length, and vigor index were measured. The results demonstrated that doses of 1.0 to 2.0 mL L⁻¹ promoted greater bioactivity, with a 7.3% increase in root length compared to the control. Although increased salinity progressively reduced all variables, with severe effects at −0.6 and −0.8 MPa, the treatment with the extract showed superior performance to the mineral fraction, demonstrating a mitigating effect. It is concluded that A. nodosum extract is an effective strategy to attenuate the damage caused by salinity on seed germination and initial seedling growth in maize, especially under moderate stress. Full article

Aril paleness (AP) is a new physiological disorder of pomegranate (Punica granatum L.) characterized by pale, dry and tasteless arils, while the peel remains healthy-looking. Its molecular basis is unknown. We used an integrated metabolomic and targeted gene expression approach on arils from four Iranian cultivars displaying no to severe AP symptoms. LC-MS profiling detected 617 reliable metabolites, with 266 metabolites consistently reduced in all symptomatic samples. Enrichment analysis revealed that arginine biosynthesis, glutathione metabolism and primary amino acid metabolism were the processes most strongly affected by AP. Protein interaction network analysis indicated that the arginine degradation pathway is the primary down-regulated module that interacts with the anthocyanin biosynthetic machinery, primarily through phenylalanine ammonia-lyase (PAL) hubs. Based on this network, seven genes representing both pathways were selected for targeted expression analysis. The qPCR analysis showed strong repression of arginase (PgADS, XM-031537872), aldehyde dehydrogenase (PgAL12A1, XM-031551051) and anthocyanin synthase (PgOXKF, KF841619.1) in the cultivar ‘Torud’ exhibiting severe AP symptoms compared with the symptom-free cultivar ‘Damavand’. In contrast, phenylalanine ammonia-lyase (PgPAL1, KY094504.2) was unexpectedly induced 33-fold in the cultivar ‘Torud’, while the downstream anthocyanin-related UDP-glucosyltransferase (PgUGT, MK058491.1) remained unchanged. These findings suggest that the collapse of arginine metabolism, combined with the downstream blockage of anthocyanin biosynthesis, underlies AP. These findings provide the first molecular insights into the mechanisms underlying AP, offering a basis for breeding and post-harvest strategies aimed at enhancing pomegranate’s AP tolerance. Full article

Aluminum (Al) toxicity is a major constraint on crop growth and productivity in acidic soils, affecting root development, nutrient uptake, and photosynthetic performance. The use of Si is a promising strategy to overcome the adverse effects of Al toxicity on species of agronomic interest. Between 2020 and 2026, 15 studies across nine species consistently demonstrated that silicon mitigated aluminum toxicity, regardless of their classification as silicon accumulators. In plants, Si mitigates Al toxicity through a combination of physical, chemical, and biochemical mechanisms that operate simultaneously. In the rhizosphere, Si interacts directly with Al³⁺ ions, favoring the formation of hydroxyaluminosilicates (HASs), which reduces the bioavailable fraction of Al. Evidence indicates that solution pH is a critical factor governing HAS formation, with minimal attenuation of Al toxicity observed at pH values below 4.5. Within the plant, Si modulates the antioxidant defense system by enhancing the activity of enzymes such as catalase, peroxidase, and ascorbate peroxidase, thereby reducing oxidative stress typically triggered by Al toxicity. Moreover, Si influences the biosynthesis of lignin and phenolic compounds with Al-chelating capacity, contributing to detoxification at the cellular level. In soybean and rice, Si supply substantially reduced Al deposition in the root apical cell wall, with decreases of approximately 52% and 41.3%, respectively. This reduction was consistently associated with improved root elongation, maintenance of root structural integrity, mitigation of cellular deformation, and preservation of root thickness and vascular organization. Although these mechanisms have been described, a comprehensive synthesis of studies published from 2020 to 2026 has been lacking, particularly regarding the integration of in-plant processes and species-specific responses. This review fills this gap by critically examining recent findings, highlighting the multifaceted role of Si in alleviating Al stress, and discussing implications for agronomic applications in acidic soils. Collectively, the evidence underscores Si as an effective tool to enhance plant tolerance to Al; however, most available evidence is derived from early plant developmental stages and hydroponic or highly controlled systems, which limits the direct extrapolation of these findings to soil and field conditions. Future advances will require studies under soil environments, accounting for species-specific responses, soil properties, management systems, and plant developmental stages. Full article

Seed priming studies commonly emphasize growth and physiological responses, yet ionomic regulation and tissue-specific nutrient allocation under salinity stress remain poorly explored, particularly in underutilized crops such as Bambara groundnut (Vigna subterranea L.). This study investigated whether Mg(NO₃)₂ seed priming, previously shown to enhance salt tolerance, is associated with consistent ionomic patterns in contrasting Bambara groundnut genotypes (BGN-14 and BGN-25). Seeds were primed with 0.03% Mg(NO₃)₂ and grown under control or saline conditions (200 mM NaCl) for five weeks. Shoot and root tissues were analyzed for macro- and micronutrient composition using ICP-OES. In BGN-14, salinity caused a marked reduction in shoot fresh weight (−49.5%, p < 0.05), whereas Mg(NO₃)₂ priming largely mitigated this effect under salinity (−0.4%, p > 0.05). Root fresh weight declined numerically under salt stress (−70.1%) and primed + salt conditions (−45.5%), but these changes were not statistically significant. Shoot dry weight increased significantly in primed plants (+83.5%, p < 0.05), while salinity reduced SDW (−58.4%); primed + salt plants maintained SDW near control levels (+2.6%). In BGN-25, root biomass was unaffected by treatments, whereas salinity significantly reduced shoot biomass relative to primed plants, with a consistent trend of primed > control > primed + salt > salt. Salinity increased the Na⁺/K⁺ ratio, particularly in roots. In BGN-14, the root Na⁺/K⁺ ratio increased significantly from 1.07 to 4.49 (p < 0.05), indicating enhanced Na⁺ accumulation, while shoot ratios increased non-significantly. BGN-25 showed a more moderate increase in shoot ratios and a pronounced rise in root ratios. Principal component analysis revealed distinct nutrient clustering, with Na, Fe, and Al loading strongly under salinity, while Ca, K, Mg, and Cu aligned with improved physiological performance. Although differences between salt and primed + salt treatments were often not statistically significant, several ion ratios and nutrient relationships were numerically enhanced under Mg(NO₃)₂ priming. This study builds upon earlier physiological findings (where BGN-14 consistently exhibited a stronger positive response to Mg(NO₃)₂ priming, outperforming BGN-25 under salt stress) and provides exploratory, hypothesis-generating evidence that Mg(NO₃)₂ priming may contribute to salinity tolerance through coordinated ionomic adjustments, including altered Na⁺ allocation and improved nutrient balance, rather than complete Na⁺ exclusion. These findings highlight the relevance of ionomic responses in understanding stress adaptation in underutilized legume crops. Full article

Aluminum chloride (AlCl₃), a widely used inorganic polymeric coagulant in everyday products and industrial materials, has been associated with male reproductive toxicity, though its molecular mechanisms remain poorly understood. To investigate the complex molecular mechanisms underlying GC-1spg cells’ responses to AlCl₃ exposure, transcriptome and small RNA (sRNA) sequencing analyses were performed. Transcriptome sequencing identified 1168 differentially expressed genes (DEGs), while sRNA sequencing detected 65 differentially expressed microRNAs (DEMs). An mRNA–miRNA regulatory network was established, and functional enrichment analysis showed that its target genes were significantly associated with multiple signaling pathways, particularly the p53 pathway. Further validation via Western blot and Hoechst 33342 staining assays confirmed that GC-1spg cells underwent apoptosis upon AlCl₃ exposure via the p53 signaling pathway. Among the identified DEMs, mmu-miR-503-5p was found to enhance GC-1spg cells’ tolerance to AlCl₃-induced stress. Moreover, dual-luciferase reporter assays and RT-qPCR confirmed that mmu-miR-503-5p directly binds to the Islr gene, which plays a role in modulating GC-1spg cell tolerance to AlCl₃-induced stress. These findings provide critical insights into the molecular mechanisms governing GC-1spg cells’ responses to AlCl₃ exposure. Full article