Introducing nanoparticles (NPs) typically enhances the strength of composite, but compromises ductility. This study breaks this trade-off in TiB2 nanoparticle-reinforced Al-Zn-Mg-Cu composites, achieving a simultaneous increase in both properties. Through systematic investigation of microstructural evolution and strain-hardening behavior, we reveal that how NP addition dictates the dislocation dynamics and ductility. Crucially, composite ductility exhibits a non-monotonic trend, with a peak at 3 wt% where the composite surpasses the unreinforced alloy in both strength and ductility. We rationalize this synergy by developing a physics-based model that incorporates NP-dependent dislocation recovery kinetics. This model quantitatively explains and accurately analyzes the ductility trends: at low NP contents (1-3 wt%), NPs retard dislocation recovery, delaying necking, while at high NP content (5 wt%), recovery is accelerated. Microstructural analysis indicates that low NP addition suppresses localized slip band formation, promoting uniform dislocation distribution and stabilizing plastic flow. This work provides a fundamental understanding of dislocation-NP interactions and offers an assessment tool for designing high-performance metal matrix composite alloys by NP-induced dislocation dynamics.

The structural nature of amorphous materials remains a long-standing challenge in condensed matter physics. The emergence of order within disorder has driven significant breakthroughs, including the discovery of quasicrystals and structural motifs in amorphous systems. Among these motifs, ring structures, which exhibit rotational symmetry without translational symmetry, play a crucial role in enabling fractal packing and longrange disorder in network glasses, such as oxide, chalcogenide, and halide systems. However, their universality in simple atomic systems, like metallic glasses, remains unsolved. Here, a four-membered Frank-Kasper (FK) cluster ring structure, denoted as 4M-Ring, has been proposed to be a consistent structural model for a metastable amorphous phase of Cu-Zr-Al-Y bulk metallic glasses. This medium-range structural motif, about 15 & Aring;, is geometrically stable and energetically favorable. The addition of yttrium (Y) as a minor alloying element facilitates the formation of the 4M-Ring by occupying its central position and linking four edge-sharing FK polyhedra. Furthermore, evidence from electron microscopy and small-angle neutron scattering suggests that 4MRings organize into a nanoscale network with diffuse interfaces, reducing interfacial energy and enhancing exceptional thermal stability. Our findings suggest the possibility of the presence of novel Frank-Kasper mediumrange order in metallic glasses with minor additions and reveal new structural principles that govern amorphous materials.

Accurate isotope compositions of nanoparticles in planetary materials provide critical constraints on the evolution of the early solar system. Atom probe tomography (APT) can analyze isotopes in situ with the highest spatial resolution, making it ideal for nanoscale planetary materials. However, significant deviations between isotope ratios determined using APT and a traditional mass spectrometer have hindered the wide application of APT in isotope analysis. Here, we propose that these isotope ratio discrepancies arise from different uncounted rates of the isotopes in APT analysis. Theoretical assessment indicates that such discrepancies can be corrected using a suite of reference materials. Iron isotope analyses of Fe-Mn-Ni steels and meteoritic irons using APT and a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS) confirm a strong linear correlation between the two data sets, supporting the establishment of 56Fe/54Fe and 57Fe/54Fe calibration curves for APT data correction. The calibration curves were subsequently validated using four meteoritic irons with known Fe isotope ratios. Combining all of the errors, our corrected APT results achieve a 2σ uncertainty of <0.15‰ for δ56Fe. This precision demonstrates that our calibrated APT protocol enables accurate isotope determination, unlocking the potential of APT for precise isotope analysis of nanoscale planetary materials.

High-temperature tensile behavior in Al-Si-Mg cast alloys is governed not only by matrix softening, but by how interdendritic intermetallics concentrate stress and sustain crack linkage. Cu-Mn addition shifts this response by stabilizing the matrix and replacing (3-AlFeSi with less deleterious alpha-AlFeMnSi, thereby improving strength at 200-300 degrees C.

ABSTRACT Eutectic high‐entropy alloys (EHEAs), a typical bioinspired lamellar composite, have the potential to achieve high strength and good ductility simultaneously for structural applications through microstructure modification. However, an extreme modulus/hardness mismatch between constituent phases leads to premature fracture and severely limits the achievable yield strength by impeding plasticity at room temperature. Here, a CoCrFeNiTa0.4 EHEA designed via suction casting followed by precise thermal treatment, which exhibits sessile interface defects and hierarchical nano‐multiphase structures consisting of FCC‐Laves eutectic lamellae, L12 and D022 coprecipitates, attains a near‐theoretical yield strength of 2.6 GPa alongside sufficient plasticity of 13.6%. This breakthrough is attributed to multiple mechanisms, characterizing soft‐FCC nanolamellae strengthened by coherent L12 precipitates, sessile planar faults, and misfit‐interface dislocations, while hard‐Laves nanolamellae are toughened by deformable D022 precipitates. All of these factors lead to the reduced modulus/hardness mismatch between FCC and Laves lamellae. The results indicate that the long‐range modulus/hardness‐matching and short‐range heterostructure, via hierarchical multiple phases and defects, are pivotal for next‐generation dual‐ and multi‐phase alloys to achieve theoretical strength while retaining impressive plasticity.

Metal additive manufacturing often produces coarse columnar grains and elemental segregation, resulting in anisotropic mechanical properties and degraded corrosion resistance. We present a powder blending strategy using multicomponent carbides (MCCs) to overcome these limitations in 316L stainless steel. Upon dissolution, MCCs drive the self-assembly of uniformly distributed core-shell oxynitride-carbide nanoparticles, which sequester detrimental nitrogen/oxygen impurities and markedly refine austenite grain size from 43.9 to 2.1 micrometers. This unique microstructure control yields an excellent combination of strength and ductility. Crucially, the corrosion resistance is enhanced by suppressing chromium segregation via tungsten, niobium, and tantalum partitioning to the cell boundaries and facilitating the formation of a protective tungsten trioxide-rich passive film. This work establishes an instructive paradigm for metal additive manufacturing, demonstrating how MCCs' introduction can tailor nanoprecipitations, grain structure, and alloy chemistry to simultaneously improve strength and corrosion resistance in structural alloys.

This study systematically investigates the recovery, static recrystallization (SRX) and grain growth behaviors of a cold-rolled grain-oriented electrical steel during isothermal annealing by using electron backscatter diffraction, transmission electron microscopy and atom probe tomography. The experimental findings reveal that the recovery and SRX act as the dominant mechanism at the early stage, while the grain growth of recrystallized grains plays the predominant role during later stage for isothermal annealing below recrystallization temperature. The SRX nucleation rate was controlled by the stored strain energy in deformed structures which was determined by recovery and SRX. The SRX primarily nucleates near the GBs or within the shear bands inside γ-fiber texture (< 111 > //ND). After the recrystallization fraction reached saturation, classical Avrami model was modified to evaluate the recrystallization kinetics below recrystallization temperature. Furthermore, an empirical formula correlating the average grain size with annealing temperature above recrystallization temperature is established. This formula enables the estimation of primary recrystallized grain sizes under varying recrystallization temperatures, thereby identifying optimal primary recrystallization annealing parameters to achieve ideal secondary recrystallization microstructures.

Achieving a favorable combination of high strength and excellent ductility remains a central challenge in the development of lightweight steels due to the inherent strength–ductility trade-off. Here, we integrate atom probe tomography, electron microscopy, and thermodynamic calculations to elucidate Cu-enabled dual-precipitation mechanisms in a Fe–Mn–Al–C lightweight steel. We show that Cu directly promotes B2 precipitation via Cu–Al clustering, while indirectly facilitating intragranular κ-carbide formation by increasing the effective carbon activity in austenite. This dual-precipitate architecture synergistically enhances strength and strain-hardening capability. As a result, the Fe–12Mn–8Al–1C–3Cu steel annealed at 850 °C achieves a yield strength of 756 MPa, an ultimate tensile strength of 1084 MPa, and an exceptional elongation of 48.2%. These findings provide mechanistically grounded solute-engineering strategy for overcoming the strength–ductility trade-off in lightweight steels.

The size-dependent electronic and phononic configurations of single atoms and nanoclusters enable tailored functionalities. Their synergistic effects also attract attention, yet precise control of anti-aggregation states during high-temperature operations poses formidable challenges in multiple fields such as fuel cells and thermoelectrics. Herein, we develop a solution-processed strategy to precisely incorporate Pt species as isolated atoms (Pt1) and sub-nanoclusters (Ptn, ∼1 nm) in Bi2S3. Notably, Ptn of 1 nm size exhibit significant advantages over larger-size counterparts in tuning electronic structure and optimizing charge transfer. Furthermore, Pt1 and Ptn scatter 1 Å- to 1 nm- wavelength phonon that is conventionally underexplored. The 1 nm Ptn exhibits distinct force constant as compared to 3 nm Ptn, leading to ultra-strong phonon Rayleigh scattering, which in turn significantly reduces thermal conductivity. The optimized Bi2S3-Pt1/Ptn composite achieves breakthrough thermoelectric performance, attaining a maximum zT of 1.02 at 773 K and single-leg conversion efficiency of 1.58%, both setting benchmarks for Bi2S3 systems. This strategy can also be extended to other thermoelectric material systems such as Bi0.4Sb1.6Te3, PbTe, or other fields including solid-state batteries and solar cells.

Al-Ce-based alloys processed using laser powder bed fusion (LPBF) are characterized by a high-volume fraction of eutectic networks. While exhibiting promising elevated temperature (250-400 degrees C) mechanical properties, they suffer from strength degradation after prolonged thermal exposure and a decrease in elongation-to-fracture (epsilon f) with increasing temperature. Here, we show that adding 5 wt.% TiC particles to a near-eutectic Al-10Ce-4Ni (wt. %) (AlCeNi) alloy mitigates both issues, albeit at the expense of reduced room-temperature epsilon f. TiC addition reduces solute supersaturation in the alpha-Al matrix, increases the volume fraction of intermetallics, and promotes a more homogeneous melt-pool-scale microstructure. It also enhances thermal stability, as evidenced by a higher hardness retention ratio after thermal exposure, due to the suppressed coarsening of intergranular Ni-rich phases and the formation of a stable Al20Ti2Ce phase. AlCeNi exhibits an epsilon f dip over 250-350 degrees C, caused by aggravated void nucleation and growth in the relatively softer heat-affected zone (HAZ), even with an increased strain rate sensitivity (SRS). TiC addition induces melt-pool-scale homogeneity and a TiC-matrix heterogeneity, shifting strain localization from HAZ to TiC particles. The failure evolves from TiC particle cracking (RT-200 degrees C) to void nucleation (300-400 degrees C), enabling more progressive damage evolution. This weakens the heterogeneity-induced reduction in epsilon f under the increased SRS at RT-350 degrees C, thereby eliminating the epsilon f dip. These findings identify TiCassisted composition control as an effective route to simultaneously enhance thermal stability and suppress epsilon f dip in LPBF near-eutectic Al alloys for high temperature service.

Achieving a sharp Goss texture remains a major challenge in the development of high-grade grain-oriented electrical steels (GOESs). Here, we show that increasing Sn addition from 0.04 to 0.08 wt% effectively sharpens the Goss texture during secondary recrystallization. Transmission electron microscopy and atom probe tomography reveal that higher Sn addition promotes smaller AlN-MnS composite inhibitor formation, and enhances Sn segregation at inhibitor/ferrite interfaces and grain boundaries. Such Sn segregation reduces inhibitor/matrix interfacial energy, facilitating smaller inhibitor nucleation and increasing their thermal stability. Consequently, Zener pinning is sustained to higher temperatures, delaying inhibitor coarsening and dissolution, elevating the onset of secondary recrystallization temperature, and amazingly leading to a sharper Goss texture. These findings provide mechanistic insights into texture control and suggest a pathway for engineering Goss texture sharpness in next-generation high-grade GOESs. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

This study investigates the influence of ceramic particles on controlling recrystallization and enhancing thermal stability in the pre-deformed aluminum matrix composite. Using an Al-Mg alloy reinforced with TiB2 particles as a model system, we demonstrated that ceramic particles act as potent nucleation sites for recrystallization while pinning grain boundaries to effectively inhibit the growth of recrystallized grains. This synergistic effect results in a significantly refined and thermally stable microstructure in the composite compared to the unreinforced alloy. We proposed a quantitative method to estimate the pinning force of TiB2 particles and thermal activation energy (Q) for grain growth from microstructure characterization. Our analysis reveals that the pinning force is not static but is influenced by the heat treatment schedule, and the grains recrystallized during low-temperature annealing exhibit a higher Q value for subsequent growth at elevated temperatures. This enhanced stability is attributed to the large grain boundary curvature resulting from particle-stimulated nucleation (PSN) at low temperature, which is then effectively stabilized by the TiB2 particles. These findings provide quantitative insights into the synergistic effects of PSN and Zener pinning, offering guidelines for designing particle-reinforced metal matrix composites with exceptional microstructural stability for demanding high-temperature applications.

The strength-ductility trade-off in oxygen-containing titanium alloys has long been limited by the embrittling nature of octahedral interstitial oxygen (oct-O). Herein, by integrating controlled laser powder bed fusion (L-PBF) processing with Cu─O co-alloying, we achieve, for the first time, the thermodynamic stabilization of hexahedral oxygen (hex-O) configurations, which redefines the role of oxygen in titanium alloys. We showcase such interstitial engineering of oxygen relies on two key regimes: (1) Cu-induced charge redistribution creates an electronic environment that preferentially stabilizes hex-O sites through strong d-p orbital hybridization, (2) rapid solidification process enabled by L-PBF effectively suppresses the Ti─Cu excessive eutectoid reaction, preserving the integrity of strong Cu─O dipole chemical bonds. Mechanistically, hex-O enhances -component dislocation activity through localized lattice distortion while maintains effective strain hardening via long-range interactions with dislocations. This atomic-scale manipulation in interstitial O enables an unprecedented strength-ductility synergy of the titanium alloy, with a yield strength of 1121 MPa and a fracture elongation of 10.2%. Our work demonstrates a new pathway for tailoring the mechanical properties of oxygen-tolerant titanium alloys via interstitial engineering.

Thermal aging of duplex stainless steels induces nanoscale microstructural changes in δ-Fe that are closely associated with δ-Fe hardening. This study investigates the effect of solution treatment on spinodal decomposition, G-phase precipitation, and δ-Fe hardening in a Mo-lean duplex stainless steel using nanoindentation and atom probe tomography, aiming to clarify the nanoscale mechanisms governing δ-Fe hardening during thermal aging. A prolonged solution treatment (15 h) effectively reduced δ-Fe area fraction, but increased δ-Fe’s Si content by ∼27%, which dramatically promoted G-phase nucleation after 1000 h aging, compared to 3000 h in the 1 h-treated sample. Notably, the initial G-phase precipitates in the 15 h-treated sample exhibit different chemical compositions and growth kinetics compared to those in the 1 h-treated sample. By resolving hardening effects of each microstructural feature using Ardell and modified Orowan models, both G-phase precipitation and spinodal decomposition contribute greatly to the δ-Fe hardening. New understanding gained from this research is important for predicting long-term mechanical stability and safe service performance of duplex stainless steels components.

A yield strength model is developed for the TiB2 nanoparticle (NP) reinforced precipitate-hardened aluminum (Al) matrix (TiB2/Al–Zn–Mg–Cu) composites based on microstructure characterization. According to the performance of alloy and counterpart composites with different particle additions (1, 3, 5 wt pct) and established model, the strength increments caused by reinforced particles and precipitates were quantified. The calculated results indicate that NPs addition may deteriorate to the strengthening contribution by precipitates. In particular, the negative influence of NPs on the strength increment caused by matrix precipitates should be attributed to the formation of interface precipitates at NP/Al interface and coarse MPs near dislocations pinned by NPs. The present work paves a way to understand the strengthening mechanisms in multi-phase strengthened alloys/composites.

NiTi shape memory alloys produced via additive manufacturing are suffering low tensile strength, low total elongation, and unstable superelasticity, thus failing to meet the requirements of practical applications. Here, we report an strategy to substantially and synergistically improve the strength, ductility, and superelasticity of NiTi produced by laser powder bed fusion through establishing high-density Ni-rich local chemical inhomogeneity (LCI) entities within B2 matrix. Compared with other documented microstructures such as long-range ordered Ni4Ti3 precipitates, the present Ni-rich LCI entities are unique to increase the resistance against dislocation slip, facilitate stress-induced martensitic transformation, and most importantly, relieve local stress concentration around micro-pore defects and entity interfaces. This specialized microstructure endows tensile superelasticity, i.e., tensile ultimate strength of 958.7 MPa, total tensile elongation of 11.2%, superelastic strain exceeding 7%, and superior cyclic stability. The results advance our capabilities in fabricating high-performance superelastic SMAs with complex geometries through additive manufacturing and LCI engineering. Using laser powder bed fusion and a tailored heat treatment, the authors produce NiTi shape memory alloys with improved strength, ductility, and superelasticity enabled by high-density of Ni-rich local chemical inhomogeneity entities.

This study investigates the hot deformation mechanisms of a spray-formed 7050 Al-Zn-Mg-Cu alloy, focusing on the influence of temperature and strain rate via comprehensive microstructure characterization. Microstructure analysis reveals that both the dynamic recovery (DRV) and dynamic recrystallization (DRX) are governed by the Zener-Hollomon parameter (Z). DRV-formed substructures exhibit distinct stability: grains with high grain orientation spread (GOS, 3-4 degrees) stabilize at low temperatures, while those with low GOS (1-2 degrees) stabilize at high temperatures. Elevated temperature promotes DRX, but the operative mechanism critically depends on strain rate. Continuous DRX (CDRX) dominates at low rates (0.001-0.01 s(-1)), whereas discontinuous DRX (DDRX) prevails at high rates (0.1-1 s(-1)). Optimizing strain rate is key: low rates (0.001 s(-1)) achieve near-complete DRX and grain growth (80 % recrystallized area), while high rates (1 s(-1)) limit recrystallization (<= 50 % area) despite enhanced nucleation, yielding finer grains (5-15 mu m) with residual substructures. Local strain analysis shows recrystallized grains maintain low kernel misorientation (KAM<0.8 degrees), but high strain rates increase substructure KAM by 41.3 %, indicating incomplete energy dissipation. This study provides new insights on the microstructure modification by deformation for developing high performance aluminum alloys.

The effect of an additional short spike aging treatment (SA: 180 to 220 degrees C, in tens of seconds) between the solution heat treatment and conventional pre-aging (PA: 85 degrees C, in hours) on the mechanical properties of an AA 6014 alloy after paint baking was evaluated. Tensile tests show that such enhanced pre-aging including SA and PA can significantly improve the paint bake response compared to conventional pre-aging (PA only). To interpret this phenomenon, Positron Annihilation Lifetime Spectroscopy, electrical resistivity measurements, Differential Scanning Calorimetry, Transmission Electron Microscopy, Atom Probe Tomography and MatCalc calculations were applied to identify the microstructural changes in different aging stages. It is found that the excess vacancies available after quenching assist in rapid nucleation of clusters during SA, which grow during subsequent PA and transform easily to beta" precipitates during paint baking owing to their similar chemistry. The densely distributed beta" precipitates are considered responsible for the improved paint bake strength as they efficiently hinder dislocation movement.

In present work, an Al–Mg–Si-Sc-Zr alloy with high Mg/Si ratio and the combined addition of Sc, Zr elements was designed to fabricate the cast Al alloys with uniform microstructure. The effect of heat treatment on the microstructure evolution and mechanical properties of designed Al–Mg–Si-Sc-Zr alloy was investigated. The scanning electron microscopy and transmission electron microscopy were used to analyze the second phase evolution. The result suggests that the aging temperature mainly affects the size, phase type and number density of matrix precipitates. It confirms that both the strength and ductility are controlled by precipitates, which are strongly dependent on aging temperature. With proper heat treatment, the ductility of materials is notably enhanced from 2.6% to 13.3% by high number density of nano-sized precipitates (β’’ phase) and plate-like GPII zones with {111}Al habit plane. The formation of plate-like GPII zones should be attributed to the high Mg content of Al–Mg–Si alloys and named as GPII-Mg zones. The β’’ precipitates and GPII zone may precipitate at the Al/Al3(Sc,Zr) interface to form the interface precipitate. High Mg/Si ratio and combined addition of Sc, Zr may provide new insights on alloy design strategy for high performance cast Al–Mg–Si alloys.

This study explores the novel synthesis of high-density core-shell structured nanoprecipitates (NPs) within FeCrNi alloys via ion irradiation, aiming to enhance mechanical properties through NPs. We have successfully prepared NPs in FeCrNi with an average diameter of similar to 15.2 nm and a number density of similar to 2.03 x 10(22) m(-3) by employing ion irradiation. Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT) results show the unique core-shell structure of these NPs, consisting of Cr-rich M23C6 carbides cores and Ni-rich shells. The ion irradiation process facilitated the controlled formation of these nanostructures by inducing localized vacancies, which allowed the nucleation and growth of NPs uniformly distributed within the alloy matrix. This synthesis method overcomes traditional limitations posed by thermodynamic constraints and grain boundary (GB) agglomeration, providing a potential pathway for the precise tailoring of microstructures. The combination of APT and TEM analysis offers detailed insight into the structural evolution of the core-shell NPs. These findings represent ion irradiation as an effective technique for fabricating novel nanostructures and hold potential for further improvements in mechanical properties, particularly in the strength, of FeCrNi alloys. Future studies will focus on evaluating the impact of varying irradiation parameters and carbon content on the structural and mechanical characteristics of these alloys.