5383 Al-Mg alloy is widely used in marine structures owing to its low density, high specific strength, good formability, and excellent corrosion resistance. However, its relatively high Mg content makes it susceptible to β-phase (Al₃Mg₂) precipitation at grain boundaries, which deteriorates both mechanical performance and corrosion resistance. In this work, the synergistic effects of cold rolling and stabilizing heat treatment (SHT) on the microstructure evolution, mechanical properties, and corrosion behavior of 5383 Al alloy were systematically investigated, with particular emphasis on the microstructural origin of the strength-corrosion trade-off. The results show that increasing the rolling reduction from 14% to 22.8% significantly improves the ultimate tensile strength from 377 MPa to 403 MPa, which is associated with grain elongation, a higher fraction of low-angle grain boundaries, and a more homogeneous distribution of the Al-Mn phase. Subsequent SHT at 180-250 °C slightly decreases the tensile strength with increasing temperature, but markedly improves corrosion resistance. In particular, β-phase precipitation is evident after SHT at 220 °C, whereas it is effectively redissolved at 250 °C, leading to a substantial reduction in intergranular corrosion depth to below 100 μm. The results demonstrate that the synergy between deformation-induced boundary structure evolution and temperature-dependent phase regulation enables an improved balance between strength and corrosion resistance. This study provides new insight into microstructure-mediated property optimization in high-Mg Al alloys and offers practical guidance for the processing design of corrosion-resistant marine aluminum alloys.

The arc welding of 7xxx series Al-Zn-Mg-Cu aluminum alloy is notoriously challenging due to solidification cracking, multi-scale pores and microstructure segregation. These defects commonly lead to brittle fracture in the weld zone (WZ) and inferior mechanical properties, even after post-welding heat treatment (PWHT). In this study, a novel Sc/Zr-modified Al-Zn-Mg-Cu alloy filler wire with high alloying content was developed. By using a low-heat-input cold metal transfer welding method, a crack-free AA7075-T6 joint with a low porosity of 0.11% was successfully fabricated. The significant increase in nucleation density, provided by primary micron-scale Al3(Sc,Zr) particles, resulted in a fully-equiaxed dendritic microstructure within the WZ. This fine equiaxed structure enhanced interdendritic liquid feeding during the final solidification stage and shortened crack propagation path, thereby reducing hot cracking susceptibility. After PWHT, the dissolution of coarse brittle eutectic structures, combined with homogeneous precipitations of nano-scale eta '-MgZn2 and secondary L12-Al3(Sc,Zr) phases, substantially improved the hardness of WZ exceeding than that of the base material. Consequently, the joint fracture location shifted to the base material rather than the traditional WZ, achieving a super combination of ultimate tensile strength (592 MPa) and elongation (13%). This work demonstrated a viable strategy for highquality arc welding of the traditionally "non-weldable" 7xxx series Al alloys.

Aluminum (Al) alloys, especially the 5xxx and 7xxx series, are widely used in various applications due to their excellent mechanical properties achieved through alloying. Exploring the effect of alloying elements on the corrosion resistance of Al alloys is an important step in the development of high-performance Al materials. In this work, density functional theory (DFT) calculations were utilized to examine the role of alloying elements on galvanic corrosion behavior in 5xxx and 7xxx series Al alloys, and the impact of aggressive ions on the protective properties of their passive films. According to the DFT calculation results, the potential difference between the Al matrix and Mg2Al3 shows an initial decrease followed by an increase as the concentration of Mg increases in 5xxx series alloys (Al-Mg). For 7xxx series alloys (Al-Zn-MgCu), increasing Cu content enhances the susceptibility to galvanic corrosion. Additionally, competitive adsorption diagrams of various ions on the passive film of the alloyed Al in chloride-containing solutions were plotted. The Si-additive in the film promotes the adsorption of hydroxide ions (OH-) on the passive films, thus effectively blocking the penetration of harmful Cl- ions. However, when passive films are modified by Mg, Zn, or Cu additives, the film degradation is accelerated. This study explains the mechanisms of microgalvanic corrosion and ion adsorption on the passive film of Al alloys, thereby providing the theoretical basis for designing corrosion-resistant alloys.

Aluminum matrix composites (AMCs) are of broad importance owing to their high specific strength and modulus; however, conventional architectures with uniformly dispersed reinforcements commonly achieve strengthening at the expense of ductility and toughness. Taking inspiration from natural spider silk, this study designs AMCs with alternating soft-hard heterogeneous architectures and, further drawing on the processing concept of Chinese lamian, exploits an accumulative extrusion strategy combining cyclic extrusion with hot-press consolidation. This approach enables effective refinement and controlled modulation of the heterogeneous architecture, which fundamentally alters the damage and fracture mechanisms, driving a transition from crack penetration through hard regions to crack deflection around them and their pull-out from the soft matrix. As a result, tensile ductility and mechanical energy absorption are substantially enhanced, leading to a superior strength-ductility synergy. Impact toughness is also significantly improved owing to delayed crack initiation and impeded crack propagation. This study demonstrates a viable processing route and structural modulation strategy for enhancing the ductility and toughness of aluminum and other metal matrix composites while maintaining strengthening.

Carbon nanotube (CNT)-reinforced aluminum matrix composites have attracted significant attention due to their promising properties. Fracture toughness and impact toughness are essential for their use in structural applications. In this study, CNT-reinforced 2009Al alloy composites with varying CNT contents were fabricated, and their microstructure, nanoindentation and tensile properties, fracture toughness, and impact toughness were systematically characterized and compared with those of CNT-free alloy. The results reveal anisotropic structural characteristics of the composites across multiple length scales, leading to pronounced mechanical anisotropy, with properties along the extrusion direction markedly surpassing those along the transverse direction. The increase in CNT content leads to enhanced nanoindentation hardness, reduced modulus, and tensile strength, but results in a compromise in plasticity and toughness. The mechanical properties were analyzed in relation to the microstructures and microscopic fracture characteristics. This study is expected to offer insights for the structural applications and component design of CNT-reinforced aluminum matrix composites.

Ultrahigh-strength medium-Mn steels are one of the promising third-generation advanced high-strength steels with strength-ductility-toughness synergy. However, it has been a challenge to preserve the superior mechanical properties of ultrahigh-strength medium-Mn steels after fusion welding due to the high heat input-induced transformation of metastable microstructures. In this work, ultrahigh-strength medium-Mn steel plates with 1GPa strength were joined by a solid-state welding technique—friction stir welding. Defect-free joints were fabricated under a specific parameter window. Transformation of austenite to quenched martensite with high hardness occurred in the nugget zones (NZs). All the as-welded joints exhibited equal strengths but significant losses in ductility compared to the base metal (BM). Moreover, the impact energies of the NZs were greatly reduced to less than 6J, which induced premature failures of the joints. After post-weld annealing at an intercritical temperature, reverse transformation of austenite occurred in the NZs, producing a composited structure of ultrafine ferrite, martensite, and austenite. The impact energies of the annealed NZs increased to over 23J, which was much higher than the 2.2J measured in the as-welded counterparts. The hardness of the NZs was significantly reduced, enabling sizeable tensile elongations of the joints close to that of the BM. Consequently, enhanced strength-ductility-toughness synergy of ultrahigh-strength medium-Mn steel joints was achieved by post-weld annealing. This work demonstrates a viable method to fabricate ultrahigh-strength medium-Mn steel joints with high performance.

A heat-treatment strategy for corrosion mitigation is demonstrated in a quasicrystal containing Mg-4Li-6Zn-1Y-1Ca (wt.%) alloy through solute redistribution and secondary phase network reconstruction. To our knowledge, this is the first report showing that heat treatment-induced construction of a continuous secondary phase network can improve the corrosion resistance of quasicrystal containing Mg-Li alloys. Unlike conventional strategies that aim to eliminate cathodic phases, the present approach enhances corrosion resistance through the coupled effects of secondary phase continuity and dissolution-induced solute redistribution. During heat treatment, the high-potential icosahedral quasicrystalline phase (I-phase, Mg3Zn6Y) partially dissolves, releasing Zn and Y. The released Y preferentially partitions into the Ca2Mg6Zn3 phase to form (Ca, Y)2Mg6Zn3, while part of the Zn dissolves into the α-Mg matrix, thereby reducing local potential differences and weakening micro-galvanic corrosion, as confirmed by SKPFM and DFT analysis. Meanwhile, the Ca2Mg6Zn3 phase evolves from discontinuous rods into a continuous network, which suppresses the nucleation and lateral propagation of filiform corrosion, as observed in situ. Heat treatment also increases the MgO fraction and promotes CaCO3-assisted pore sealing in the corrosion products, leading to a denser and more protective surface film. As a result, the corrosion rate decreases by approximately 70% relative to the as-cast alloy. These findings demonstrate that engineering secondary phase continuity and solute redistribution provides an effective strategy for improving the corrosion resistance of Mg-Li-Zn-Y-Ca alloys containing multiple secondary phases.

This study introduces a hard-plate warm-rolling followed by annealing (HPWR&A) method to create a bimodal heterogeneous structure (BiHS) in a carbon nanotube (CNT)-reinforced 2009 Al alloy composite. Compared to conventionally hot isostatic pressed (HIP) samples, the BiHS sample exhibited significant enhancements in yield strength (504 MPa) and uniform elongation (similar to 10 %), increasing by 59 % and 73 %, respectively. Microstructural analysis revealed that the BiHS sample possessed a dual-scale grain structure, primarily established during hot pressing and extrusion, with warm rolling playing a supplementary role in refining grain morphology. This structure consisted of elongated coarse grains (ECGs, similar to 2.1 mu m) and ultra-fine grains (UFGs, similar to 0.3 mu m), accompanied by favorable Schmid factor textures that facilitated multiple slip system activation. Subsequent annealing led to the dissolution and redistribution of Al2Cu precipitates into a finely dispersed state, effectively inhibiting crack initiation. Deformation analysis indicated that ECGs predominantly accommodated plastic strain, while interactions with UFGs contributed to strain hardening. Moreover, the HPWR&A process enhanced CNT dispersion, reducing interfacial instability and improving compatibility between the reinforcing phases and the matrix. These results elucidate the multiscale microstructural mechanisms underlying the enhanced strength-ductility synergy in metallic matrix composites.

In the present work, the creep behavior and microstructural evolution of Al-Cu-Mg alloy, homogeneous CNT/Al-Cu-Mg composite, and heterogeneous CNT/Al-Cu-Mg composite were systematically compared under varying stress levels. The results indicate that the introduction of CNTs markedly reduces the creep rate and enhances the creep resistance of the alloy; however, the regional distribution of CNTs has a significant effect on the creep behavior. Although the homogeneous composite exhibits a higher yield strength, its creep resistance is inferior to that of the heterogeneous composite. Microstructural characterization reveals that pronounced grain boundary sliding dominates the creep deformation of the Al-Cu-Mg alloy, whereas this mechanism is effectively suppressed upon CNT incorporation. Nevertheless, CNT agglomeration in the composites induces heterogeneous dislocation distributions, promoting strain localization. Meanwhile, the adsorption of solute atoms by CNTs leads to interfacial segregation and solute depletion within grains, thereby inhibiting the nucleation and growth of intragranular precipitates. In contrast, the heterogeneous composite, consisting of CNT-depleted zones (CDZs) and CNT-rich zones (CRZs), effectively mitigates local stress concentration and improves deformation compatibility during creep through the construction of a regionally distributed heterogeneous microstructure. The strain partitioning between the CRZs and CDZs promotes the accumulation of geometrically necessary dislocations (GNDs) near the hetero-interfaces, thereby providing the basis for hetero-deformation-induced (HDI) strengthening. Meanwhile, the coarse-grained microstructure within the CDZs exhibits a more homogeneous dislocation distribution and a stronger precipitation strengthening effect, which together endow the composite with superior creep resistance. The results indicate that constructing a heterogeneous microstructure with a tailored regional distribution of CNTs is an effective strategy to simultaneously optimize creep resistance and service stability in CNT/Al-Cu-Mg composites.

This study focuses on typical nano-phase reinforced 2009Al matrix composites, aiming to clarify how reinforcement types affect their quench behavior. Results show significant differences in quench sensitivity between composites with different reinforcements, primarily attributed to reinforcement distribution and thermal mismatch with the matrix. For nano-sized SiC, its high surface energy leads to a tendency to segregate along grain boundaries in the composites. During quenching of SiC/2009Al composites, this distribution triggers significant Cu element segregation at grain boundaries. Additionally, the large difference in coefficients of thermal expansion (CTE) between SiC and the matrix results in a high density of thermal mismatch dislocations induced during quenching, which further reduces the stability of the supersaturated solid solution. Ultimately, this leads to significant performance degradation of thick-section components after quenching. In contrast, nano-sized Al2O3 has lower surface energy, allowing part of the reinforcements to easily disperse inside the grains. Consequently, the segregation of alloying elements along grain boundaries in Al2O3/2009Al composites during quenching is alleviated. Meanwhile, the smaller CTE difference between Al2O3 and the matrix reduces the density of thermal mismatch dislocations, improving the stability of the supersaturated solid solution. This thus substantially mitigates the performance degradation of thick-section components. These findings indicate that Al2O3 as reinforcement favors alleviating strength attenuation from quench sensitivity in large-sized Al matrix composite components.

This study investigated the effect of rolling process on the recrystallization behavior and mechanical properties of 7B65 Al alloy. The results show that the precipitation behavior of Zr-containing phases during hot rolling was the key factor regulating the recrystallization evolution of the material after heat treatment. At a low rolling temperature (350 degrees C), Zr-containing phases were difficult to precipitate sufficiently, resulting in a high recrystallization fraction after heat treatment. With the increase in rolling temperature (420 degrees C) and deformation degree, the content of Zr-containing phases increased accordingly, which effectively suppressed recrystallization during heat treatment. A lower recrystallization fraction corresponded to a higher dislocation density inside the material, leading to more significant growth of precipitates under the same T74 aging condition. Among all processing parameters, the specimen processed by hot rolling at 420 degrees C with a thickness reduction of 80% achieved the optimal comprehensive mechanical properties: the tensile strength reached 592 MPa while maintaining a high elongation of 12.5%. This was mainly attributed to its moderate recrystallization degree, which not only promoted sufficient precipitation of strengthening phases but also effectively inhibited their excessive coarsening.

Aluminum matrix composites (AMCs) combine low density, high specific strength, wear resistance, and thermal management capability, but reinforcement-induced interfaces, residual stresses, and microstructural heterogeneity may promote localized corrosion and environmentally assisted cracking (EAC). This review focuses on EAC of AMCs in aqueous environments, particularly stress corrosion cracking and hydrogen-assisted cracking, while corrosion fatigue is considered selectively. Anodic dissolution, hydrogen-assisted damage, passive film rupture, interfacial debonding, and crack-tip chemistry are examined in relation to the condition-dependent transition from localized corrosion to crack initiation and propagation. EAC testing and complementary characterization methods are compared, with attention to AMC-specific interpretation. The effects of matrix composition, reinforcement characteristics, grain-boundary precipitation, interface structure, processing, residual stresses, environment, loading, and heat treatment are critically assessed. Conflicting trends are interpreted through stage-dependent electrochemical, mechanical, interfacial, and hydrogen-related effects. Direct AMC-EAC evidence is distinguished from corrosion-precursor, mechanical-only, and transferred evidence, with conclusions qualified by data comparability. Mechanism-guided mitigation strategies involving alloy design, interface engineering, processing optimization, surface protection, and surface mechanical treatments are discussed, followed by unresolved questions and experimental priorities for improving AMC durability.

In this paper, continuous SiC fiber-reinforced 2024Al (SiCf/2024Al) composites were prepared using matrixcoated fibers and hot isostatic pressing (HIP) consolidation. The microstructure evolution of the interface and matrix during HIP was investigated using XRD, SEM, EPMA, TEM, and TKD techniques. The results show that: 1. The densification between the matrix and capsule is better under the HIP process of fibers at 480 degrees C/110 MPa/3 h; 2. The size of the amorphous carbon layer at the interface during the HIP process is increased from 5 nm to 15 nm, in addition to the fact that no AlxCy interfacial reaction product is detected at the interface; 3. In the precursor wires stage, the grain boundaries of alpha-Al have been formed, with the formation of Al2Cu and Al2CuMg phases have been formed at the grain boundaries of alpha-Al, and the sizes of Al2Cu and Al2CuMg phases in the matrix increase during HIP. In addition, HIP promotes the diffusion of elements such as Fe, Mn, etc., and Al20Cu2Mn3 and Al7Cu2Fe phases are formed at the grain boundaries.

To address interfacial regulation in low-pressure heterogeneous joining of titanium alloys and titanium matrix composites, diffusion bonding experiments were conducted on TC4 alloy and TiBw/TC4 composites at 930 °C under a low pressure of 10 MPa. The effects of holding time on interfacial microstructure evolution and mechanical properties were investigated. The results show that, under low bonding pressure, interfacial bonding evolves from initial physical contact to a stage governed primarily by atomic diffusion and void healing. With increasing holding time, the interfacial voids gradually shrank and eventually disappeared. Meanwhile, elements such as Al and V diffused across the interface and undergo selective redistribution. This process promoted the β→αs phase transformation and gradually connected the α and βt microstructures across both sides of the interface, leading to improved microstructural continuity. During prolonged holding, creep deformation of the surrounding matrix caused some interfacial TiBw to become partially embedded in the opposite TC4 matrix, improving local interfacial stability and load transfer. The interfacial shear strength increased to 708 MPa after holding for 70 min, approaching the average shear strength of the TC4 alloy. The fracture mechanism changed from rapid brittle propagation dominated by interfacial voids to crack deflection induced by TiBw reinforcements.

By implementing an intragranular distribution strategy for Al2O3 nanoparticles, an Al2O3/Al composite with ultra-high strength-ductility synergy was fabricated. The research shows that nano Al2O3 particles in hot-pressed composites were mainly located at grain boundaries, while hot extrusion promoted grain boundary migration, facilitating the migration of nano Al2O3 particles into the grains. A critical model related to materials (including reinforcement content, size) and hot deformation parameters was proposed to describe the grain boundary migration and intragranular behavior of nano reinforcements, which provides a criterion for intragranular distribution regulation. The tensile results indicate that the intragranular nano Al2O3 particles triggered highly efficient Orowan strengthening, significantly enhancing the strength. Meanwhile, the intragranular nano Al2O3 particles induced more uniform proliferation of dislocations, effectively promoting the coordinated deformation between the grain boundaries and the grain interior, thereby enhancing the elongation. Finally, a prepared 3 vol. % Al2O3/2009Al composite exhibits a yield strength exceeding 700 MPa and an elongation of up to 9 %, achieving a synergistic enhancement of both high strength and high ductility in metal matrix nanocomposites.

Thermal debinding is a safe and environmentally friendly debinding method for removing the binders during the process of metal parts manufacturing by bound metal deposition (BMD). In this study，the binders in the sample are effectively removed using thermal debinding method by reducing the sample wall thickness. The structures applicable to thermal debinding in bound metal deposition additive manufacturing and the energy absorption characteristics of sintered metal parts are deeply analysed. The results show that the sheet structure with a wall thickness of 0.45 mm does not produce obvious deformation，blistering and cracks after thermal debinding. The prepared thin-walled structure with curved thin walls in the interior does not induce obvious deformation，blistering or cracks after thermal debinding and the thin-walled metal structure after sintering only has small number of micron pores. The thin-walled metal structure has good energy absorption effects. The energy absorption is 19.2 J and the specific energy absorption is 6.6 J/g of the thin-walled metal structure during the compression process，which is 187% higher than the specific energy absorption of two-dimensional thin-walled metal structures (mainly honeycomb structures) in the results of the published literature.

Powder metallurgy is an ideal method for fabricating particle reinforced magnesium matrix composites, while thermomechanical processing is essential for controlling their formability. However, research on the hot working process and microstructure evolution mechanisms remains insufficient. This study systematically investigates the hot deformation behavior and dynamic recrystallization (DRX) mechanism of a 15 vol% SiCp/AZ31 composite fabricated by powder metallurgy. Uniaxial hot compression tests under different temperatures (350-500 degrees C) and strain rates (0.001-1 s-1) were conducted on a Gleeble 3800 simulator. Microstructural evolution and the underlying DRX mechanisms were elucidated using electron backscattered diffraction (EBSD). The results show that the flow stress behavior is characterized by initial work-hardening, followed by either softening/stabilization under most conditions or a continuous rise at 450-500 degrees C/0.001 s-1 . The hyperbolic sine model was identified as the most accurate constitutive equation for predicting flow stress. The processing map indicates the optimal processing region within the range of 460-500 degrees C/0.1-1 s-1 , where DRX proceeds sufficiently and is governed by particle stimulated nucleation (PSN, 32.3 %)) and discontinuous DRX (18.3 %). In contrast, the instability region found at 360-420 degrees C/0.05-1 s-1 , which featured micro-voids within the AZ31 matrix, is dominated by PSN (28.5 %) and continuous DRX (8.7 %). With an average deformation activation energy of 155.29 kJ/mol and an average stress exponent of 4.18, the primary deformation mechanism of the composite is identified as dislocation climb controlled by lattice diffusion.

Aluminum matrix materials are essential for lightweight structural applications, yet their performance under high-temperature cyclic loading is constrained by microstructural instability. This study presents a novel synthesis route initiated at the powder precursor stage to fabricate an in-situ (Al2 O3 + Al3 Ti)/Al composite. The approach combines a hybrid sol-gel process with powder metallurgy, first establishing a reinforcement network along grain boundaries and then enabling partial incorporation of the reinforcements into grain interiors, thereby achieving synergistic strengthening through coordinated intra- and intergranular mechanisms. The composite exhibits exceptionally high-cycle fatigue resistance at 350 degrees C, delivering a fatigue strength of 97 MPa-significantly higher than that of conventional heat-resistant aluminum alloys. Through multi-scale characterization using X-ray computed tomography, neutron diffraction, and microstructural analysis, the underlying strengthening mechanisms were systematically elucidated. Nanosized Al2 O3 particles effectively pin dislocations and suppress grain coarsening, promoting stable dislocation networks that enhance microstructural stability, while the Al3 Ti intermetallic phase contributes to load-bearing capacity and alleviates stress concentration through anti-phase boundary formation. The synergistic combination underpins the composite's excellent fatigue endurance, offering valuable insights for designing advanced aluminum matrix composites with enhanced thermal stability. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Abnormal grain growth (AGG) has long plagued Al-Zn-Mg-Cu alloys produced by friction stir welding (FSW), making them unsuitable for post-welding heat treatment. Here, we propose an innovative wire-arc assisted FSW (WA-FSW) approach to realize in-situ Sc/Mn micro-alloying in 700 MPa-grade Al-Zn-Mg-Cu alloys. Primary Al3(Sc, Zr) and Al6(Fe, Mn) particles are successfully introduced into the nugget zone of WA-FSW joints. These thermally stable particles exert strong Zener pinning pressure against grain boundary migration, thereby effectively suppressing AGG during subsequent heat treatment. After heat treatment, the nugget zone consists of submicron Al6(Fe, Mn) particles distributed along grain boundaries and high-density L12-ordered Al3(Sc, Zr) and η/η'-MgZn2 nanoprecipitates formed within fine recrystallized grains. The dense weld formation and homogeneous microstructures contribute to an excellent tensile strength of 640 MPa together with a favorable elongation of 8% in the heat-treated WA-FSW joint. Compared with existing solutions for AGG suppression, our strategy exhibits superiorities in terms of grain refinement, microstructural homogeneity, and mechanical property improvement. These insights provide new theoretical support for the controllable fabrication of high-performance welded joints through weld composition design, elevating the microstructure regulation of FSW joints from “passive adaptation” to “active design”.