This study prepared three Ni30Co30Cr10Fe10Al18W2 eutectic high-entropy alloys (EHEAs) in different thermomechanical states (one phase-selective recrystallization (PSR) state and two post-processing (SPSR) states), and systematically characterized their initial microstructural parameters to identify the key factors governing their mechanical properties. Quasi-static and dynamic tensile property tests were conducted on the three samples. The results show that in high strain rate tensile tests, the strength of the three alloys is significantly improved (the yield strength of the PSR alloy increases by 32.9%, and the ultimate tensile strength of the SPSR-2 alloy increases by 12.4%), while the failure strain decreases. Fractographic analysis reveals three distinct failure modes under dynamic loading: in the PSR state, cracks predominantly distribute along the FCC/B2 phase interfaces; in SPSR-1, cracks nucleate and localize within the BCC phase; in SPSR-2, cracks initiate in the BCC phase and then extend into the FCC phase, accompanied by secondary cracking. Based on these microstructural characteristics and considering strain rate effects, a dynamic constitutive model was established, uniquely integrating key micro-structural parameters: grain size, interfacial spacing, and dislocation density. The model demonstrates excellent predictive accuracy across all three states, highlighting its generality beyond a single microstructure. This work not only deciphers the strengthening and failure mechanisms under impact loading but also provides a quantitative framework for tailoring thermomechanical processing to achieve targeted property combinations in EHEAs for specific applications.

FCC/B2 dual-phase high-entropy alloys (DHEAs) exhibit great potential for high-temperature applications due to their unique combination of low density, excellent mechanical properties, and good oxidation resistance. However, achieving an optimal strength-ductility balance at elevated temperatures remains a challenge. In this study, the dual-phase and precipitation structures of FCC/B2 DHEAs were systematically tailored by varying the Ni/Co content. It was found that an increased Ni/Co ratio resulted in a lower fraction of the B2 phase and promoted L12 precipitation within both the FCC and B2 phases. The optimized microstructure was featured by a balanced combination of dual-phase matrix and high-density precipitates. At 800 degrees C, the increased volume fraction of L12 precipitates improved the yield strength, while the retained B2 phase effectively suppressed intergranular cracking, thereby preserving ductility. These findings offer a practical strategy for designing low-density, high-performance FCC/B2 DHEAs for future high-temperature structural applications.

In physical metallurgy, partially recrystallized microstructures show great potential for performance improvement through tailored thermo-mechanical processing. It is widely accepted that increasing the recrystallized faction generally reduces strength while enhancing ductility. However, deviations from this trend have long been recognized, stemming from competing effects of texture, dislocations, grain boundaries, and precipitates. These anomalies also raise an important question: can hidden factors beyond recrystallized fraction and aforementioned factors break the strength-ductility trade-off? Using machine learning, we identify the boundary between soft recrystallized and hard non-recrystallized regions as the determinant to the mechanical properties of partially recrystallized alloys. Through micro-digital image correlation (mu DIC), we verify that a pronounced strain gradient is generated near this boundary, which contributes to additional strain hardening capacity and ductility. The increased boundary density thus overcomes the strength-ductility trade-off in partially recrystallized alloys.

A core-shell microstructure represents an approach to achieve superior mechanical properties in alloys through its distinctive architecture, typically developed in powder metallurgy processing. In the present study, an integral core-shell structure has achieved in a cast Ni-based high entropy alloy through a straightforward thermo-mechanical processing (TMP) approach, including hot rolling and heat treatment. Inspired by the formation of a necklace structure during the hot deformation, we employed hot rolling to induce bulged grain boundaries in coarse grains. Subsequent heat treatment constrained the growth of these bulged regions through B2 precipitate formation, leading to the stabilization of the integral core-shell structure, where the deformed grains form the core, and the bulged grains form the shell. The significant synergistic hardening from the microstructural heterogeneity of the integral core-shell structure improves strain hardening in the TMP-processed sample. The integrated TMP approach, combined with alloy design, enables the evolution of integral core-shell structures in cast high entropy alloys, significantly improving material properties without the complexities of powder metallurgy. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Designing precipitation-strengthened FCC/B2 dual-phase high-entropy alloys promotes the development of structural materials with high mechanical performance and lower density. In the present work, Ti and Ta were utilized as alloying elements in a Ni43.9 Co19 Cr10 Fe10 Al15 Mo2 B0.1 alloy to concurrently enhance the precipitation strengthening in both the FCC and B2 phases. In the FCC phase, the alloying elements increased the volume fraction of L12 precipitates and anti-phase boundary energy, thereby enhancing the precipitation-strengthening effect. In the B2 phase, the alloying elements promoted the formation of FCCstructured precipitates with refined inter-precipitate spacing and thus improved the Orowan strengthening contribution. With the harder B2 phase, the more significant hetero-deformation-induced hardening enhanced the alloy strain hardenability. Although ductility decreased, the continuous stacking fault glides and phase transformations in the FCC-structured precipitates contributed to the strength-ductility synergy by preventing intragranular cracking and mitigating crack propagation in the B2 phase. These findings provide valuable insights for the future design and development of precipitation-strengthened FCC/B2 dual-phase high-entropy alloys. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

L12-strengthened FCC/B2 dual-phase high-entropy alloys (HEAs) exhibit excellent mechanical performance across a broad temperature range, positioning them promising candidates for hightemperature structural applications. However, microstructural coarsening and associated mechanical degradation under prolonged thermal exposure remain key challenges. In this study, a representative alloy with the composition Ni41.9Co19Cr10Fe10Al15Mo2Ti2B0.1 (at. %) was subjected to long-term aging at 800 degrees C, revealing an unusual microstructural evolution. Beyond the expected L12 coarsening within the FCC phase, an interfacial L12 shell formed via the progressive consumption of L12 precipitates from both the FCC and B2 phases, ultimately encapsulating the B2 domains. This transformation produced a unique three-level hierarchical architecture: FCC matrix with intragranular L12 precipitates, an interfacial L12 shell, and a B2 core. Remarkably, despite this pronounced microstructural evolution, the alloy maintained stable strength-ductility synergy from room temperature up to 800 degrees C. This stability is attributed to the additional strengthening imparted by the interfacial L12 shell and the favorable cooperative deformation among the FCC, B2, and interfacial L12 phases. A quantitative strengthening model was established, revealing that the strengthening contribution of the L12 shell increases with increasing shell thickness and exceeds 100 MPa after 720 h of aging. These results provide valuable guidance for the design of thermally stable precipitation-strengthened dual-phase HEAs for long-term hightemperature applications.

The hot deformation behavior and microstructure evolution of a GH4698 Ni-14Cr-2.6Ti-1.7Al-2.9Mo-2.1Nb superalloy was investigated through isothermal compression tests. A strain-compensated constitutive equation was established to reliably effectively flow stress behavior. The microstructural evolution under different deformation conditions was systematically analyzed, revealing distinct dynamic recrystallization pathways. At low temperatures, both discontinuous dynamic recrystallization (DDRX) via grain boundary bulging and continuous dynamic recrystallization (DRX) via subgrain rotation were active. As the temperature increases, twin boundary–assisted recrystallization at low-energy interfaces in GH4698 alloy is activated, providing an additional nucleation route. In addition, this work reports for the first time that low temperature deformation in GH4698 alloy leads to the formation of step-shaped grain boundaries. These boundaries serve as low-energy migration paths, which significantly facilitate grain boundary movement. These findings provide new mechanistic insights into DRX in Ni–Cr superalloys and establish a framework for optimizing thermoplastic processing of advanced aerospace alloys.

In this work, a coupled multiscale microstructural design strategy was developed for a Cu-5Ni-0.7Si-0.4Al alloy by integrating partial recrystallization-induced grain heterogeneity with hierarchical precipitation. Partial recrystallization produced heterogeneous grains spanning the micrometer to submicrometer scale, while Ni-Si–Al alloying promoted a site-dependent precipitate hierarchy, including intergranular δ-Ni2Si, intragranular δ-Ni2Si, and nanosized Ni-Al-enriched precipitates consistent with an L12-ordered structure. The resulting architecture is inferred to regulate dislocation motion and improve strain compatibility during deformation. The optimized alloy achieves a yield strength of 800 MPa, an ultimate tensile strength of 840 MPa, an elongation of 15%, and an electrical conductivity of 38% IACS.

Magnesium (Mg) alloys are highly sought after for lightweight applications due to their exceptional properties; however, their inherent tension-compression asymmetry, intensified by plastic deformation and characterized by the disparity between compressive yield strength (CYS) and tensile yield strength (TYS), limits broader utilization. In this study, we leverage a comprehensive Mg alloy database, encompassing compositional elements, extrusion parameters, and microstructural texture, to predict the CYS/TYS ratio using machine learning (ML) techniques. Feature analysis, guided by Pearson correlation and data-driven insights, uncovered key parameters influencing mechanical properties. By comparing multiple ML models, we optimized feature subsets to accurately predict TYS, CYS, and CYS/TYS ratio. Additionally, we conducted an in-depth analysis of the relationships between input features and the target variables using SHapley Additive exPlanations (SHAP). This integrative approach provides a robust framework for reducing tension-compression asymmetry in Mg alloys, thereby enhancing their applicability in structural and multifaceted engineering applications.

The pursuit of advanced wear-resistant materials for cryogenic applications is often hindered by a fundamental trade-off of enhancing strength and damage tolerance. CoCrNi-based medium-entropy alloys (MEAs), while excellent in cryogenic toughness, suffer from this very limitation. Although second-phase reinforcement boosts strength, the strain incompatibility between phases inevitably triggers cracking, which is severely exacerbated at low temperatures. This work introduces a novel microstructural design strategy based on regulated partial recrystallization to overcome this longstanding challenge. By tailoring the thermomechanical processing of a (CoCrNi)90Mo10 MEA, we engineered a unique architecture where a fully recrystallized FCC phase is homogeneously embedded within a continuous skeleton of a hard, non-recrystallized σ phase. The alloy with this optimized microstructure achieved a remarkably low wear rate at 113 K that is less than half of its as-cast and fully recrystallized counterparts. The experimental and modeling results indicate the underlying synergy: the σ skeleton provides robust structural support and distributes stress deeply, while the recrystallized FCC phase, with its high density of grain boundaries and annealing twins, acts as a compliant strain-accommodating medium, effectively suppressing interfacial cracking. This combined “skeleton effect” and “recrystallization effect” not only delivers exceptional cryogenic wear resistance but also offers a practical strategy for designing high-performance, crack-resistant dual-phase composites for extreme environments.

ABSTRACT The need to simplify processing routes and improve processing efficiency motivates the development of time‐efficient methods for inducing the columnar‐to‐equiaxed transition (CET) during solidification while tailoring material performance. Conventional multistep CET approaches are time‐consuming and often struggle to simultaneously regulate thermal conditions, grain morphology, phase evolution, and functional properties, making it difficult to balance structural and functional properties. Here, we propose a one‐step magnetic‐field‐assisted solidification strategy to achieve CET in the low‐cost Al 0.5 CoCrFeNi high‐entropy alloy (HEA) within 2 h, reducing the processing time by up to 93% while simultaneously enhancing its mechanical and magnetic responses. The combined effects of thermo‐electric‐magnetic convection (TEMC) and thermoelectric magnetic force (TEMF) may modify local heat transport and promote dendrite fragmentation near the solid–liquid interface. These effects facilitate CET with a more pronounced [100] orientation, leading to improved mechanical and magnetic responses. Under optimized conditions, the hardness of the FCC phase increased by 9%, the magnetization increased by 10.5%, and the coercivity decreased by 21.1%. Meanwhile, the BCC region exhibited a Young's modulus of 159.8 GPa and a hardness of 6.01 GPa. Our work offers a streamlined and composition‐preserving strategy for promoting CET with simultaneous mechanical and magnetic enhancements, advancing alloy development for microstructure and property control in materials processing.

Designing precipitation-strengthened FCC/B2 dual-phase high-entropy alloys (HEAs) is an effective method for preparing structural materials with superior strength and lower density at elevated temperatures. However, highdensity precipitates in FCC/B2 dual-phase HEAs will also cause a sudden drop in ductility, especially for the B2 phase with insufficient slip systems. Here, by tailoring the precipitates of disordered FCC and ordered L12 in the B2 phase, we achieved significant ductilization of the B2 phase. With the ductilized B2 phase, the precipitationstrengthened FCC/B2 dual-phase HEAs exhibited superior strength-ductility synergy over a wide temperature range. At 650 degrees C, it was different from traditional understanding that the hard L12 precipitate improved the deformability of B2 via sustainable stacking fault shearing, whereas the soft FCC precipitate transformed into the hard 18 R phase which reduced the B2 ductility by suppressing the dislocation motion of the B2 phase. By tailoring the precipitates in the B2 phase from FCC to L12, the strain localization near the FCC/B2 phase boundary was significantly decreased and premature cracking was inhibited, leading to the superior ductility. These findings advance the microstructural design of precipitation-strengthened FCC/B2 dual-phase HEAs by introducing hard yet ductile precipitates to the B2 phase to enhance ductility, shedding light on the development of alloys with exceptional mechanical properties and lower density at elevated temperatures.

Dislocations govern the plastic deformability of structural alloys. However, this beneficial role is compromised in refractory multi-principal element alloys (RMPEAs), where tensile ductility degrades owing to plastic strain localization via planar slip and dislocation channeling. We proposed a ductilization concept based on engineered dislocation channels to divert and dredge dislocations, achieving a notable tensile ductility of 21 % and a yield strength exceeding the gigapascal mark in the as-cast RMPEA. To test the hypothesis that enhanced lattice distortion and chemical fluctuations act as dislocation diverters, we designed Ti53V15Hf32 (V15) and Ti41V27Hf32 (V27) RMPEAs with distinct volume misfit and Warren-Cowley parameters. In-situ synchrotron highenergy X-ray diffraction and transmission electron microscopy analyses revealed that increasing the volume misfit facilitates a transition in dislocation character from edge-based (V15) to screw-based (V27) under tensile loading. Atom probe tomography and high-angle annular dark-field scanning transmission electron microscopy characterizations further demonstrated that elevated V content engenders pronounced chemical fluctuations, inducing diversion of dislocation slip and the formation of river-like dislocation channels. These dislocation channels, on one hand, promoted dynamic strain hardening through dense intersections of the channel boundaries. On the other hand, they prevented premature necking and failure by enabling dislocations to proliferate and cross-slip within channels. Consequently, the river-like dislocation channels delayed plastic instability at ultrahigh yield strength, thereby enabling the RMPEA to unleash exceptional tensile ductility. These findings provide a dislocation-harnessing pathway for pursuing strength-ductility synergy in RMPEAs.

Phase and grain boundaries can effectively strengthen dual-phase high-entropy alloys (HEAs), but as service temperature increases, they could also become sources of weakness and damage. In this work, microstructures with different phase and grain boundary densities were designed in a hypoeutectic HEA to compare their different effects on cracking behavior at elevated temperatures. The tensile ductility significantly increased by reducing the intergranular fracture with decreased grain boundary density. The analyses revealed that the grain boundary was prone to crack at the triple junctions and served as the crack propagation path. Differently, although the phase boundary also cracked preferentially, it was highly resistant to crack propagation by its serrated morphology and defects emission at the crack tip. The directionally solidified sample further proved the benefit by suppressing the intergranular cracking, achieving a higher yield strength of-701 MPa and considerable tensile ductility of-31.5 % at 800 degrees C. These findings create a microstructural optimization pathway based on the cracking mechanisms, aiming to produce high-performance dual-phase HEAs for application in a wide temperature range.

The existing state of charge (SOC) balancing scheme of the lithium battery energy storage system (LBESS) does not consider the state of health (SOH) of LBESS in the process of energy distribution, which results in an inability to reduce SOH balancing errors and increases maintenance costs for LBESS. To solve this problem, an SOC balancing scheme for LBESS of microgrids considering SOH is proposed. In this scheme, SOC equalization factor and health status factor (HSF) are introduced into droop control, and the power output of LBESS inverter is adjusted according to SOC and SOH status so as to achieve SOC balancing and reduce SOH imbalance errors. Simulation and experimental results demonstrate that the proposed SOC balancing factor and HSF can maintain SOC balancing and reduce SOH balancing difference even under load fluctuations by adjusting the output active power of LBESS. With the implementation of SOC balancing, its SOC balancing factor becomes zero, thereby achieving a frequency stabilization effect. In addition, the proposed solution has good effects in multiple LBESS scenarios and LBESS charging processes.

Phase-selective recrystallization (PSR) is an effective strategy for improving the mechanical properties of eutectic high-entropy alloys (EHEAs). Via PSR treatment, the recovered hard phase and the recrystallized soft phase work together to fully release the strain-hardening capacity of EHEAs. However, few studies have focused on optimizing the PSR structures in EHEAs. In this study, we systematically investigated the effect of annealing temperature and rolling times on the PSR of Ni44Co10Cr12Fe15Al17W2 EHEA and obtained the processing window in PSR. At a lower annealing temperature of 800 degrees C, the annealed sample maintained a lamellar structure with both FCC and B2 phases recovered. As the annealing temperature increased to 1000 degrees C, the fully recrystallized FCC phase and the recovered B2 phase, that is, the PSR structure, were obtained after the second cold rolling and subsequent annealing. At 1200 degrees C, both FCC and B2 phases recrystallized into equiaxed grains. The PSR sample showed a doubled ductility of 27 % and a similar yield strength of 868 MPa compared to the as-cast sample. Our strengthening and fracture mechanisms analysis showed that the high strength of PSR EHEA mainly came from the boundary-strengthening of the lamellar structure, and the reduced crack nucleation sites caused by the PSR structure ensured its excellent ductility. These findings indicated that the properties of the EHEA could be further improved using PSR treatment for a wide range of engineering applications.

This study explores the correlation between microstructural features and the mechanical properties of innovatively developed Ni30Co20Cr20Fe20Al6Ti2Ta2 high entropy alloy. A high density of y'-L12 nanoprecipitates was observed within the grains and along grain boundaries. The alloy achieved a yield strength (YS) of 761.05 MPa, an ultimate tensile strength (UTS) of 1062.1 MPa, and a total elongation (TE) of 55.7 % at 298 K. At 77 K, the YS increased to 991.8 MPa, the UTS to 1511.2 MPa, with an appreciable TE of 47.4 %. The properties improved significantly with the decrease in temperature from 298 K to 77 K. The alloy exhibited strong temperature dependency, progression of a planar-slip deformation mechanism at 298 K to dense dislocation array or Taylor lattice at 77 K. The interaction of dislocation arrays with y' precipitates enhanced the strain-hardening ability, delaying necking and preserving TE at cryogenic temperature. The present research lays the foundation for the development of advanced alloys with superior properties for cryogenic applications.

The relatively low creep resistance of magnesium (Mg) alloys limits their application in high-temperature environments. Mg-Gd-based alloys, however, exhibit exceptional creep resistance, making them promising candidates for such applications. This review comprehensively examines recent advancements in the characterization and optimization of Mg-Gd-based alloys, focusing on key factors influencing their creep resistance. Key strategies for improving creep resistance include precise composition optimization with rare-earth elements such as Y and Nd, combined with Zn, Ca, Mn, and Al elements to alter precipitation behavior and enhance thermal stability. Thermomechanical processing has emerged as a critical tool to further improve creep resistance by tailoring grain structure and precipitation states. Furthermore, the review highlights the integration of machine learning to predict and design creep-resistant alloys, enabling cost-effective and accelerated development pathways. The discussion extends to future perspectives in optimizing Mg-Gd-based alloys for diverse industrial applications. This work serves as a detailed guideline for researchers and engineers aiming to advance the field of high-temperature Mg alloy development.

CoCrFeMnNi high entropy alloy (HEA) is considered ideal hydrogen storage material due to its high resistance to hydrogen embrittlement (HE), but its lower mechanical strength and hydrogen desorption content restricted comprehensive application. Therefore, it was desirable to design the HEA that possessed both excellent hydrogen storage property and superior strength. In this work, the eutectic high entropy alloy (EHEA) reinforced by C14 Laves phases were designed and forecasted combined with the thermodynamic calculations and thermal desorption analysis. The results revealed that the designed CoCrFeMnNiNb0.5 EHEA with hydrogen (H) charging remained the higher hydrogen storage content of 49.2 ppm and UTS of 369.4 MPa because of the enhancement effect induced by C14 Laves phase when compared to CoCrFeMnNi HEA with H charging (20.2 ppm, 191.5 MPa). For the as-cast CoCrFeMnNi HEA with H charging, the hydrogen enrichment at grain boundaries induced stress concentration and significantly decreased strength and ductility. However, in the as-cast CoCrFeMnNiNb0.5 EHEA with H charging, the cracks were extended with random orientation in C14 Laves phases, endowing its higher strength. This work paved the way to develop advanced HEA with excellent hydrogen storage and higher strength, and demonstrates the great potential of EHEA strengthened by C14 Laves phases for hydrogen storage applications in the near future.