Crystalline-amorphous nanolaminates (C/A NLs) have long been conceived as static composites, with their performance predetermined by layer thickness and phase fractions. Here, we introduce a paradigm shift that transforms these materials into chemically adaptive systems through oxygen dynamic partitioning. By harnessing interstitial oxygen as an in-situ chemical modulator, we show that NLs can reconfigure their local chemistry during deformation, evolving from a preset structure into a self-optimizing system. We realize this concept in FeCrNi-O/TiVNbHf-O NLs, where deformation drives oxygen redistribution from the amorphous layers and interfaces to the crystalline layers, increasing oxygen content by 1.55 at.% and amplifying intralayer chemical inhomogeneity without forming oxides. This dynamic chemical evolution progressively strengthens the crystalline phase, reduces the mechanical mismatch between the two layers, and facilitates coordinated deformation throughout the entire architecture. As a result, the two phases achieve a dynamic convergence in mechanical behavior, not by design but by evolution. This chemo-mechanical coupling yields exceptional performance, delivering an ultrahigh yield strength (∼E/30, approaching the theoretical limit ∼E/10) alongside a homogeneous compressive strain exceeding 50%, with no shear band formation. The approach is broadly applicable across alloy systems and establishes chemical reconfiguration as a new design paradigm for materials that adapt rather than merely serve as passive constituents.

Revealing the atomistic origins of failure in amorphous solids remains challenging. In metal-metalloid glasses, the mechanical response is strongly governed by the breaking and reformation of covalent bonds, which cannot be adequately captured by non-reactive interatomic potentials. In this work, large-scale reactive molecular dynamics simulations using a ReaxFF potential that includes angular constraints for covalent bonding reveal a composition-dependent transition from cleavage cracking to shear banding in model Cu–Si glasses. During uniaxial tension, a highly connected, rigid Si-rich network suppresses strain dispersion, generating highly localized unstable regions characterized by shear-induced reduction in atomic number density and severe distortion of Si–Si–Si bond angles. These unstable regions serve as energetically favorable pathways along which the crack advances. As the Cu content increases, reduced angular rigidity and the enhanced connectivity of flexible Cu-centered polyhedra promote widespread shear transformation and shear band-mediated plasticity. In contrast, a modified embedded-atom method potential, which intrinsically overestimates the angular flexibility of the Si-rich structures, fails to reproduce this transition. Our results suggest that angular rigidity and its spatial heterogeneity are key descriptors of plastic deformation in metal-metalloid glasses.

Lightweight refractory high- and medium-entropy alloys (LRH/MEAs) are being explored as potential materials for lightweight applications owing to their low densities, high strengths, and excellent strengthto-weight ratios. However, their limited ductility and formability under ambient conditions restrict their broad industrial applications, particularly in the manufacturing of highly valuable, hot-sectional parts with complex geometries. Although recent studies have advanced the understanding of ductilization in these alloys, practical solutions to overcome the ambient ductility and formability limitations remain elusive. Here, we report an exceptional superformability in ambient cold-rolling of a strong-yet-ductile Ti50 V29.5 Zr10 Nb10 Mo0.5 (at. %) LRMEA, achieving a remarkable elongation of 1600 % at a thickness reduction of 96 %, without the need for intermediate stress-relieving annealing. The observed superformability arises from the adaptive buffering microstructures that evolve during the cold-rolling process, namely, slip and kink bands in the early stage, kink and shear bands in the moderate stage, and shear bands and dislocation channels in the late stage. These localized microstructures act as adaptive stress buffers, effectively mitigating stress concentrations, and thereby preventing crack initiation and propagation. After cold-rolling annealing at 400 degrees C for 1 h, the 0.2 mm-thin LRMEA strip reaches an ultrahigh yield strength of 1.5 GPa while maintaining a sufficient elongation of 10 %. These findings demonstrate that the engineering of stagewise adaptive microstructural buffers is a promising strategy for mitigating stress concentrations and achieving superior performances. This strategy can be utilized in the future design of ductile, superformable refractory alloys, such as LRH/MEAs, with potential applications in engineering sectors that require high-strength, lightweight thin strips. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The overall efficiency of electrocatalysis is governed by the microscopic mechanistic pathways, whose precise engineering remains a fundamental challenge. In this work, we report a noble-metal-free FeCrNi multi-principal element alloy catalyst featuring a supra-nanoscale crystalline/amorphous dual-phase structure, fabricated through controlled cooling during magnetic sputtering deposition. The catalyst delivers exceptional oxygen evolution reaction (OER) performance in alkaline media, achieving an ultralow overpotential of 363 mV at an industrial-level current density of 1 A cm-2 and maintaining robust stability for over 1000 h at 200 mA cm-2. Through integrated operando analyses, including distribution of relaxation times (DRT) analysis from in situ staircase potential electrochemical impedance spectroscopy, differential electrochemical mass spectrometry, attenuated total reflection surface-enhanced infrared spectroscopy, and in situ Raman, we reveal that the dual-phase structure promotes the in situ formation of FeNiOOH intermediates. These intermediates significantly enhance charge-transfer kinetics and optimize the adsorption-desorption behavior, thereby driving a mechanistic shift from the conventional adsorbate evolution mechanism (AEM) to the more kinetically favorable oxide path mechanism (OPM). Density functional theory (DFT) calculations further confirm that the FeNiOOH intermediate stabilizes *O-O* species with reduced energy barriers, facilitating the OPM pathway. Our work demonstrates a practical strategy for boosting OER performance by activating the OPM route through the rational design of crystalline/amorphous dual-phase active sites.

Metallic glasses (MGs) that mainly made up of metallic elements are a new member of the glassy materials family. This new kind of glass combines the characteristics of liquids and solids, glasses and metals, making it fascinating to both scientists and industrialists. With the discovery of more and more systems, MG is becoming one of the most active research field in metallic materials, and some concepts and technologies derived from MGs also facilitate the development of other materials from quasi-crystals to high entropy alloys. MGs have now been successfully used in aerospace, robotics, medicine, consumer electronics, etc. and the practical applications of MGs are still growing. On the other hand, the diverse properties and the unique structure of the MGs render them ideal models to study major open issues including the structural model of disordered materials, glass transition, collective motion and energy landscape. However, understanding the emerging properties and phenomena of MGs still poses enormous challenges, which has stimulated a wealth of efforts, including the development of new experimental approaches, the synthesis of systems with tailored properties, and the advancements in experimental techniques, theoretical models, and numerical simulations. In this Roadmap, we try to provide a broad overview of recent and potential future activities in the MG field, and present a roadmap for the development and applications of MGs by gathering contributions form scientists with diverse backgrounds, illustrating the major challenges and discussing the latest technology and strategy to tackle these challenges with experts covering various developments in general concepts, synthesis and characterisation, and theoretical and simulation methods.

This study explores the synergistic effects of grain size gradients, phase distribution, and strain-induced phase transformations on the plasticity enhancement of AlCoCrFeNi2.1 eutectic high-entropy alloys (EHEAs) fabricated by laser powder bed fusion (LPBF). The LPBF-processed EHEA exhibits a hierarchical microstructure composed of alternating FCC-dominated columnar grains (similar to 50 mu m thick), ultrafine BCC equiaxed interlayers (similar to 1 mu m thick), and nano-cellular structures (similar to 450 nm) within grains. This multiscale architecture achieves a strength-ductility synergy, with a yield strength of 1205 MPa, an ultimate tensile strength of 1464 MPa, and a uniform elongation of 25 %. Plasticity enhancement is attributed to the interplay of heterogeneous deformation-induced (HDI) strengthening, modulated by grain size gradients and phase heterogeneity, and dynamic strain-driven phase transformations (FCC-*9 R, BCC-*HCP) that relieve stress concentrations at FCC/BCC interfaces. Additionally, crack deflection promoted by the grain size gradient further mitigates strain localization. These findings demonstrate the potential of multiscale microstructural engineering via LPBF for designing high-performance structural materials.

The thermal strain in metallic glass (MG) can induce defect activation and alter the magnetocaloric properties, making it crucial to understand the atomic structure changes at cryogenic temperatures. This study investigated the evolution of the atomic structure and volume variation of HoErCo MG microwires as the temperature drops to the cryogenic level using in-situ high-energy synchrotron X-ray diffraction. As the temperature decreases, atomic vibrations diminish, and the disorder within the MG decreases due to cooling contraction, resulting in a reduction in average atomic volume. Through analysis of partial coordination numbers, the study revealed the formation of various solute-centered clusters during cooling. Specifically, larger rare earth (RE) elements tend to migrate toward the center of the clusters, while cobalt (Co) atoms move outward. In alloy microwires, RE atoms are more likely to aggregate with Co atoms, forming Co-RE clusters with Co at the center. This research provides a strategy for investigating the deformation and physical properties of amorphous alloys at cryogenic temperatures, potentially enabling accurate prediction of MG materials’ behavior under such conditions.

Lightweight high/medium-entropy alloys (H/MEAs) possess attractive properties such as high strength-to-weight ratios, however, their limited room-temperature tensile ductility hinders their widespread engineering implementation, for instance in aerospace structural components. This work achieved a transformative improvement of room-temperature tensile ductility in Ti-V-Zr-Nb MEAs with densities of 5.4–6.5 g/cm3, via ingenious composition modulation. Through the systematic co-adjustment of Ti and V contents, an intrinsic ductility mechanism was unveiled, manifested by a transition from predominant intergranular brittle fracture to pervasive ductile dimpled rupture. Notably, the modulated deformation mechanisms evolved from solitary slip toward collaborative multiple slip modes, without significantly compromising strength. Compared to equimolar TiVZrNb, a (Ti1.5V)3ZrNb composition demonstrated an impressive 360% improvement in elongation while sustaining a high yield strength of around 800 MPa. Increasing Ti and V not only purified the grain boundaries by reducing detrimental phases, but also tailored the deformation dislocation configurations. These insights expanded the applicability of lightweight HEAs to areas demanding combined high strength and ductility.

Grain refinement can drastically increase the strength of metals. However, this approach tends to become less effective or even inverses once grain sizes are reduced to very small scales, generally below 10 ~ 20 nanometers. This softening effect emerges from grain boundary instability and the limited ability of dislocations to form and move within such nanosized grains. However, grain boundary stability can be tuned by solute decoration or grain boundary relaxation. In this context, we present a strategy to achieve superior strength and plasticity in nanograined metals simultaneously. The formation of oxygen (O)-rich clusters at grain boundaries can significantly improve grain boundary stability, even at the 3 nm grain size model (CoCrNi)87O13 (at.%) alloy investigated in this study. Furthermore, the presence of O-rich clusters in grain interiors promotes the accumulation and multiplication of dislocations, which facilitates strain hardening during deformation. Consequently, despite being situated in the inverse Hall-Petch regime, this (CoCrNi)87O13 alloy exhibits a remarkable yield strength of ~3.6 GPa and retains a uniform plastic strain of over 50% under micropillar compression. These findings therefore provide a universal design strategy for nanograined metals aimed at utilizing O clusters to achieve the highly desired combination of high strength and large deformability.

Medium-entropy alloys (MEAs) have emerged as a promising class of materials, offering a unique combination of superior mechanical properties over their conventional counterparts. This study explores the development of metal particle-reinforced CoCrNi medium-entropy alloys (MPR-MEAs) with in-situ alloying by using laser powder bed fusion (LPBF) on mixed elemental powder blends. By optimizing the LPBF process parameters, a homogeneous distribution of incompletely melted Cr particles is achieved within the CoCrNi matrix, resulting in high-strength MPR-MEAs. The as-built CoCrNi MPR-MEA exhibits a tensile strength of approximately 734 MPa, which is nearly three times that of the as-cast CoCrNi MEA, while still maintaining an elongation of 15 %. The remarkable increase in strength is attributed to the synergistic effects of grain boundary strengthening, thermal mismatch strengthening, and dislocation strengthening. The fracture behavior is characterized by a combination of brittle and ductile modes, with microcracks nucleating from the interior of the incompletely melted chromium particles. Importantly, the chromium particle-matrix interface exhibits no signs of cracking, indicating an excellent metallurgical bond, which does not act as a crack initiator. This study demonstrates the potential of LPBF in-situ alloying for fabricating high-strength MEA composites, providing valuable insights into the design and optimization of advanced metal matrix composites for engineering applications.

In contrast to traditional intermetallics that are difficult to process and prone to cracking during additive manufacturing, our work demonstrates the successful fabrication of crack-free, high-performance CCIMAs via electron beam powder bed fusion (EBPBF). The microstructures of CCIMAs (NiCoFeAlTiB) fabricated by EBPBF are remarkably complex, exhibiting a multiphase composition where the disordered FCC phase forms the matrix interleaved with L12-ordered intermetallic phase. The unique combination of ordered lattices and high-entropy disordered phases, tuned by optimised EBPBF processing, imparts exceptional mechanical properties with a high tensile strength (similar to 1 GPa) and a sufficient ductility (similar to 11%). It is found that additional minor HCP and L21 precipitates can also effectively slow down and block the crack extension. This work demonstrates a pathway for crack-free fabrication of CCIMAs with tailored microstructures using EBPBF which may provide new insights and manufacturing strategies to unlock the potential of these advanced intermetallic alloys.

Eutectic high entropy alloys (EHEAs) have garnered significant attention due to their unique heterogeneous lamella structure, which imparts a desirable strength-ductility combination. Additive manufacturing (AM) techniques further exploit the advantageous properties of EHEAs through efficient fabrication and rapid heating/ cooling processes. In this study, we fabricate near-fully dense and crack-free AlCoCrFeNi2.1 EHEA samples with an alternating nano-scale eutectic lamellar structure composed of disordered face-centered cubic (FCC) and ordered B2 phases using the laser directed energy deposition (LDED) method. By using a novel and simple interlayer pause strategy, we have found that the eutectic lamellar structure can be significantly refined, achieving approximately 40% greater refinement compared to the case without interlayer pause. The optimized EHEA exhibits an exceptionally high strength of 1214 MPa and a sufficient uniform elongation of 16.3%, outperforming the non-interlayer-pause counterpart by 14% in strength and 47% in uniform elongation. The superior mechanical properties of the AlCoCrFeNi2.1 EHEA are attributed to the synergistic effects of heterogeneous deformation-induced (HDI) strengthening and strain hardening mechanisms. Furthermore, the refined eutectic lamellar structure can effectively mitigate stress concentration mediated the formation of microcracks, thereby delaying fracture and maintaining plasticity. The interlayer pause strategy presented in this work offers a simple yet effective approach and valuable insights for the preparation of metallic materials with exceptional mechanical properties via LDED process.

The current work focuses on the impact of mechanical protocol which can lead to either rejuvenation or relaxation of metallic glasses (MGs) through elasto-static compressive loading (ECL) treatment. Here we demonstrate that, even after imposing a long-term ECL process, the Zr52.5Cu17.9Ni14.6Al10Ti5 MG subjected to an elasto-static stress of 85% of the yield stress at room temperature shows varying degrees of rejuvenation without any relaxation. The MG undergoes an increasing trend in structural rejuvenation with an increased stored energy and a more disordered structure. Nanoindentation results reveal that the variation of mechanical responses emerges from the complementary effects of the thermal activation process and the structural heterogeneity of glassy phase. The spital heterogeneities can effectively reduce the activation barriers of the shear transformation zones (STZs) and widen their distributions, which will perturb the shear-banding processes from single motion to collective movements, leading to shear band multiplication/branching and an increase in the elastic energy density cut-off. As a result, the plasticity is significantly enhanced and the yield strength is decreased. These findings shed light on that ECL process is an effective way to enhance the structural heterogeneity and the level of rejuvenation of a monolithic MG, which may allow the design of MGs with desirable mechanical properties.

In this study, the structure changes and related mechanical properties of the Zr61Ti2Cu25Al12 metallic glass treated by triaxial compression and followed by further cryogenic thermal cycling were systematically studied. It is found that the structure evolution based on the changes in the relaxation enthalpy and diffraction peak position shows inconsistencies with each other. Vickers hardness mapping reveals that residual stresses may impart and store in the extremely deformed metallic glass sample, which can be verified from the change of hardness and that can well explain such inconsistencies. As thermal cycling proceeds, the stored residual stresses will relieve and compete with structure softening from the process of thermal cycling, leading to a tunable rejuvenation behavior. A plausible model that correlates rejuvenation and thermal-mechanical protocols is proposed. This work highlights that residual stress plays a vital role in the metallic glass rejuvenation and should be taken into account, which may be helpful for the design of metallic glasses with desired mechanical performance.

The most common strategy to enhance the plasticity of metallic glasses (MGs) is to synthesize MG composites with crystalline phases. Here, the evolution of crystallization and the correlation between void-like defects and crystallization for the as-spun and cryogenically-treated (CT) MGs are investigated under a rigorous annealing process conducted in-situ. The as-spun specimen maintains its amorphous structure with a relatively large size of nanoscale defects. However, crystallization is observed for the CT MG with a high concentration of nanoscale defects that decreases during the crystallization process. The crystallization develops readily in the CT MG due to the greater size of the ordered clusters, the higher concentration of seeding sites, and its greater nucleation rate. Our findings demonstrated cryogenic treatment could tune atomic rearrangements, which has guiding significance on designing MG composite with controlled length scales and distribution of crystalline inclusions.

Low Ag lead-free Sn-Ag-Cu (SAC) solders have attracted great interest due to their good drop resistance, high welding reliability, and low melting point. However, low Ag may lead to the degradation of the mechanical properties. Micro-alloying is an effective approach to improving the properties of SAC alloys. In this paper, the effects of minor additions of Sb, In, Ni, and Bi on microstructure, thermal and mechanical properties of Sn-1 wt.%Ag-0.5 wt.%Cu (SAC105) were systematically investigated. It is found that the microstructure can be refined with intermetallic compounds (IMCs) distributed more evenly in the Sn matrix with additions of Sb, In, and Ni, which brings a combined strengthening mechanism, i.e., solid solution strengthening and precipitation strengthening, leading to the tensile strength improved of SAC105. When Ni is substituted by Bi, the tensile strength is further enhanced with a considerable tensile ductility higher than 25%, which still meets the practical demands. At the same time, the melting point is reduced, the wettability is improved, and the creep resistance is enhanced. Among all the investigated solders, SAC105-2Sb-4.4In-0.3Bi alloy possesses the optimized properties, i.e., the lowest melting point, the best wettability, and the highest creep resistance at room temperature, implying that element alloying plays a vital role in improving the performance of SAC105 solders.

Residual stress engineering is widely used in the design of new advanced lightweight materials. For metallic glasses, attention has been given to structural changes and rejuvenation processes. High-energy scanning X-ray diffraction strain mapping reveals large elastic fluctuations in notched metallic glasses after deformation under triaxial compression. Microindentation hardness mapping hints at a competing hardening–softening mechanism after compression and reveals the complementary effects of stress and structure modulation. Transmission electron microscopy proves that structure modulation and elastic heterogeneity distribution under room temperature deformation are related to shear band formation. Molecular dynamics simulations provide an atomistic understanding of the confined deformation mechanism in notched metallic glasses and the related fluctuations in the elastic and plastic strains. Thus, future focus should be given to stress modulation and elastic heterogeneity, which, together with structure modulation, may allow the design of metallic glasses with enhanced ductility and strain-hardening ability.

In this study, three kinds of atomic disordered Cu50Zr50 metallic glass thin films (MGTFs) with different structural heterogeneities are prepared by controlling the substrate temperature in magnetron sputtering, i.e., controlling the thermal history. A work-hardening behavior is observed in the MGTFs by cyclic nanoindentation. The spatial distribution of structural heterogeneities, and the correlation length of the viscoelasticity of heterogeneity in three MGTFs with different thermal histories demonstrate the effect of thermal history on the viscoelasticity of three MGTFs. The activation volume of heterogeneity controlling the initiation of shear band during local deformation correlates the correlation length of viscoelastic heterogeneity, which is used to elucidate the relationship between the structural heterogeneity and the work-hardening behavior. The results show that the increase of the substrate temperature causes the viscosity of structural heterogeneity to be increased, which means the reduction of viscoelastic heterogeneity correlation length. In this case, the activation volume of heterogeneity in the MGTF is decreased, which leads the formation of shear band to be difficult.

The relaxation spectrum of glassy solids has long been considered to probe their structural features and deformation mechanisms. Here, by systematically investigating the structural evolution, dynamical relaxations and mechanical properties of a Zr-based metallic glass subjected to different cryogenic treatment time, we build a bridge to connect the relaxation processes and mechanical properties. It is found that the β-relaxation triggered by local excitations has no memory effect of the thermal history or initial free volume content of the system. However, some local denser areas with a high potential energy created by CT might contribute to β′-relaxation that activated at a much lower energy, which may play a crucial important role in the fundamental deformation mechanisms of metallic glasses. The relaxation behaviors and the related improved mechanical properties can be rationalized in terms of the atomic-level stress theory. These findings will advance our understanding of the intrinsic correlation between local excitations and mechanical properties of metallic glasses, thereby may help guide to develop amorphous alloys with high mechanical performance.

Both strength and ductility are essential for high-performance engineering structural materials, thus great en-deavors have been invested to solve the strength-ductility trade-off of them during recent two decades. Here, we utilized grain boundary (GB) relaxation to circumvent the trade-off in bulk pure Ni through optimizing grain size when literatures tells that GB relaxation can improve strength but ductility. Both tensile strength and uniform elongation of Ni were elevated from 1450 MPa to 2013 MPa and from 2.33% to 5.17%, respectively. The combination of strength and ductility extends beyond the range established by the strongest bulk pure Ni known. Our investigation unraveled that the increased strength was produced by GB relaxation which remarkably mitigated GB softening produced by GB sliding, and that partial dislocation emission from GBs became the dominant plastic deformation mechanism. The dislocation activities inside the grains increased the strain hardening rate (theta). At the same time, enhanced probability of interaction between dislocations and GBs improved the strain rate sensitivity (m). It was the GB relaxation induced dislocation activities that improved theta and m, which stabilized the plastic deformation to enhance ductility. The present work offers a foundation for the ongoing of more advanced engineering structural materials with the advisable design of GB complexion.