The effects and underlying mechanisms of aging treatment on the microstructure and properties of Cu-0.3Be-2.0Ni and Cu-0.3Be-2.0Ni-0.2Al alloys(subjected to solid solution treatment followed by 70%cold rolling)were investigated.Results showed that the Cu-0.3Be-2.0Ni alloy mainly precipitated the Ni-Be phase,while the Cu-0.3Be-2.0Ni-0.2Al alloy exhibited co-precipitation of both Ni-Be and Ni3Al phases.The combined strengthening from nanoscale Ni3Al and Be-Ni phases significantly increased the strength of the Cu-0.3Be-2.0Ni-0.2Al alloy compared to the Cu-0.3Be-2.0Ni alloy.Thermo-mechanical treatment improved both the hardness and electrical conductivity of the alloys.Compared with conventional aging,the Cu-0.3Be-2.0Ni-0.2Al alloy showed a 13%increase in hardness and a 6.8%increase in electrical conductivity,while the Cu-0.3Be-2.0Ni alloy exhibited a 6%hardness increase with slight conductivity improvement.

Magnesium (Mg) alloys face severe edge cracking during cold rolling due to limited slip systems and deformation anisotropy. Conventional hot rolling and heat treatment compromise efficiency and surface quality when fabricating Mg alloy thin strip. Here, we pioneered an electropulsing treatment (EPT) strategy to simultaneously heal internal defects and restore rollability in multi-pass cold rolling of Mg-1Zn-1Gd alloy. Through microstructure/defect characterizations and multi-physics simulations, we revealed that the local thermal compressive stress, induced by inhomogeneous Joule heating near defects, dominated defect healing within seconds; while a concomitant slower healing process was driven by the global compressive stress and accelerated atomic diffusion, which could result in excessive grain growth with prolonged EPT. Optimized EPT parameters achieved a balance between internal defect and microstructure, i.e. one-order reduction in defect volume fraction and a partial recrystallization state with relieved residual stress, and endowed the annealed sample with significantly enhanced ductility and superb cold rollability. Overall, this study established a scalable and efficient route for Mg alloy thin strip fabrication.

In the field of high-temperature actinide metal casting, traditional graphite crucibles face significant limitations in nuclear material processing efficiency and safety due to carbon contamination, coating delamination, and thermal stress mismatch. This study proposes a novel Nb521 alloy substrate coated with Nb-Y2O3 composite gradient layers fabricated via slurry coating and sintering processes. Systematic optimization of coating composition and structure was achieved through ABAQUS finite element simulations and experimental validation. Research demonstrates that when employing a transition layer composition of 25% Nb+65% Y2O3+5% Si+3% Mo+2% Zr paired with a pure Y2O3 surface layer, the coating exhibits a characteristic graded structure. Under 1200 degrees C thermal cycling, the maximum interfacial thermal stress of the optimized coating is reduced from 94.90 MPa (pure Y2O3 coating) to 68.80 MPa, representing a 27.5% reduction. The stress concentration zone shifts from the substrate-coating interface to the interior of the transition layer, effectively mitigating interface damage caused by the thermal expansion coefficient difference of 1.8 & times; 10-6 K- 1. Liquid cerium erosion tests at 850 degrees C reveal no apparent metal penetration, with protection mechanisms attributed to the chemical inertness of the Y2O3 ceramic layer and stress dissipation by the Nb-Si-Mo transition layer. The proposed "compositionstructure-stress" synergistic optimization strategy provides an engineering solution for reusable actinide metal casting crucibles. The developed coating demonstrates exceptional thermal shock resistance, liquid metal erosion resistance, and interfacial bonding strength, showing potential to reduce radioactive waste generation and enhance nuclear material processing safety.

Visibly transparent radiative cooling (VTRC) glass offers a promising pathway for improving building energy efficiency. However, conventional designs of vertically installed VTRC materials often focus on optimizing emission or reflection across the entire mid-infrared (MIR) spectrum, neglecting the dual demand for outward radiative cooling and resistance to incoming thermal radiation from the surroundings. Herein, we proposed a strategy for selective mid-infrared regulation to overcome the above limitations and fabricated a multi-band selective regulation radiative cooling (MBSR-RC) glass through a simple blade-coating method. The fabricated MBSR-RC glass exhibited a precisely engineered spectrum. It maintained high VIS transmittance (85%), high NIR blocking (72%), and high emissivity (87%) in atmospheric transparent windows for heat dissipation, and a high reflectivity (60%) in the remaining MIR region to resist environmental heat. Consequently, compared with conventional radiative cooling glass and low-emissivity (low-E) glass under vertical installation, the multi-band selective regulation radiative cooling (MBSR-RC) glass achieved a maximized temperature reduction of 4 °C. Furthermore, it demonstrated high practicality, with high ultraviolet resistance, low thermal conductivity, and strong anti-raindrop stability. EnergyPlus simulations showed that, compared with normal buildings, an energy saving of 3.2 kWh m-2 could be achieved in buildings employing MBSR-RC. This work provides a novel and practical design strategy for energy-saving windows, showcasing significant potential for energy-efficient building applications.

The effects of refractory metals Mo, V, Zr, Hf, and non-refractory metal Al on the phase formation, solid solution behavior, and mechanical properties of NbTa0.5Ti-based refractory multiple-principal-element alloys (RMPEAs) were studied using CALPHAD, empirical parameter analysis, and first-principles DFT, combined with vacuum arc melting experiments. The addition of Al, Mo, Hf, V, and Zr effectively enhances the strength of NbTa0.5Ti alloy. Mo significantly improves strength and deformation resistance but reduces toughness, while V improves toughness; Al, Hf, and Zr reduce toughness. NbTa0.5Ti-X (X = Mo, V, Zr, Hf, Al0.6) RMPEAs were prepared and characterized in as-cast and annealed states. All alloys show dendritic microstructures with elemental segregation. After annealing at 1000 °C for 24 h, NbTa0.5TiAl0.6 exhibits a prominent yield strength increase from 1103 MPa to 1518 MPa due to intragranular Al-rich precipitates, at the cost of compressive ductility. Experimental results agree well with computations. Strong correlations are confirmed between DFT-calculated elastic constants and experimental strength/hardness; Pugh ratio and Cauchy pressure reliably predict toughness trends. Atomic size mismatch (δ) quantitatively indicates solid-solution strengthening. This work establishes a CALPHAD + empirical parameters + DFT framework to screen effective alloying elements for strengthening NbTa0.5Ti while maintaining room-temperature compressive ductility, providing a reproducible strategy for composition–property design of high-performance RMPEAs.

Copper (Cu) has been widely used in thermal management, but the thermal conductivity is limited to -387 W m- 1 K-1. Highly ordered graphene films (GFs) demonstrate a thermal conductivity of -1800 W m- 1 K- 1 in the plane, but the structural reliability and the machinability remain challenges due to the weak interface interaction between graphene layers. Herein, we report a cost-effective yet readily scalable preparation of inch-scale copper/ graphene film/copper (Cu/GF/Cu) sandwich composites for efficient heat dissipation. The optimized thermal interface between Cu and graphene is achieved by magnetron sputtering a thin Cu layer on GF, followed by a hot compression of the Cu-coated GF in the middle with two Cu foils in vacuum to densify the sandwich structure. Owing to the atomically compact interfacial thermal coupling between Cu and graphene, the in-plane thermal conductivity (k//) of the Cu/GF/Cu composite approaches theoretical values as predicted by the linear combination of GF and Cu. The resultant Cu/GF/Cu composite with 66.7 % volumetric fraction of GFs has a remarkable k// of 805.8 W m- 1 K-1, more than double the value of Cu, demonstrating superior thermal spreading ability than the bare Cu plate on a simulated heating source. This work proposes a practical strategy towards the preparation of high thermal conductivity Cu/GF composite materials for efficient thermal management.

Airflow sensors are in huge demand in many fields such as the aerospace industry, weather forecasting, environmental monitoring, chemical and biological engineering, health monitoring, wearable smart devices, etc.

To develop ZrNb alloys with excellent surface properties, phase composition, microstructure evolution, and friction and wear properties of Zr oxide ceramic layers prepared by equilibrium and non-equilibrium techniques were investigated. Non-oxidized samples prepared with same heat treatment process were used as control group. Optical microscopy, scanning electron microscopy, X-ray diffraction, and X-photoelectron spectroscopy were employed to further investigate and establish relationships between processing, structure, and properties. There was apparent oxygen-rich diffusion zone between in-situ synthesized Zr-based oxide ceramic layer and ZrNb substrate. High residual stress, fine-grained microstructure due to insufficient growth, and high diffusion rate of elements near oxide/metal interface at 1000 degrees C resulted in high content of t-ZrO2 in non-equilibrium aqueous oxidation sample. Furthermore, the composition of equilibrium thermal oxidation samples was dominated by m-ZrO2, exhibiting the highest nano-hardness (>14 GPa) and the lowest wear rate (3.40 x 10(-8) mm(3)/Nm). Friction and wear behavior of samples under different surface conditions was investigated. Lastly, stability mechanism of metastable oxide phases and growth mechanism of Zr-based oxides were analyzed and discussed in depth.

Macroscopic carbon nanotube assemblies (CNTAs) have advanced mechanical, electrical, and optical properties and exhibit potential applications in a wide range of technological fields. These properties stem from the intrinsic structural features of individual carbon nanotubes (CNTs). Wet-drawing is the most prevalent technique in optimizing the structure of CNTAs in both academia and industry. However, the understanding of the fundamental mechanisms governing the efficacy of the wet-drawing process remains insufficient. In this work, we investigated the influence of solvents on the structural evolution of CNTAs during wet-drawing and their impact on mechanical properties via coarse-grained molecular dynamics (CGMD) simulations. Our study revealed a volcano-like relationship between an energy parameter (ε) and the assembly strength, indicating that ε significantly influences the wetting behavior of solvents toward CNTAs. An increased ε value leads to decreased orientation entropy during drawing and increased entropy during solvent evaporation, elucidating the mechanisms underlying solvent-CNT interactions. To further validate our findings, we conducted experiments using five solvents with different energy parameters. The observed trends in mechanical, electrical, and optical properties were consistent with theoretical predictions. This work establishes a framework for solvent selection to enhance CNTAs' performance, advancing their applications in high-end areas.

The immense potential of electronic textiles for wearable applications has spurred extensive research into luminescent fibers suitable for smart textile displays. However, current electroluminescent (EL) fibers, while flexible and wearable, typically emit only a fixed color and have a 1D structure, which confines fiber-based displays to pre-designed patterns. Here, a coaxial hierarchical fiber structure is fabricated with an insulating polymer layer sandwiched between an EL core and an electrochromic (EC) shell based on carbon nanotube fibers. Acting as a dynamic optical filter with RGB tri-state switching capabilities, the EC shell can effectively modulate the optical properties of inner emitted lights via a low voltage, enabling a new "electroluminochromic" fiber with multicolor luminescence and rapid on-demand color switching. Moreover, electroluminochromic bare fibers can be woven with orthogonal electrodes at discrete gel polymer electrolyte junctions, forming individually addressable luminescent pixels. Using a warp-weft knitting approach and integration with the Internet of Things, this display textile can transmit information, exhibiting great potential for applications in smart displays and wearable electronic devices.

Despite significant advancements in theoretical and experimental research, the strength of state-of-the-art carbon nanotube fibers (CNTFs) still falls short of their theoretical limits. To bridge this gap, a detailed understanding of the structure-strength relationships of CNTFs is urgently needed to guide enhancement of the fiber strength. In this work, a mesoscale quantitative model employing coarse-grained molecular dynamics simulations was proposed to investigate the relationship between the conformation of CNTFs and fiber strength. Two structural features were identified to affect the overall fiber strength by machine learning: the length-pore ratio (α) and porosity (β). An in-depth analysis of various postprocessing techniques reveals that the objective of process optimization is to maximize α while simultaneously minimizing β. When these two factors are fine-tuned, it is possible to significantly enhance the mechanical performance of CNTFs, bringing their strength closer to the theoretical predictions.

Novel compositionally complex borides, (Hf,Zr,Nb,Ti)B 2 and (Hf,Zr,Nb,Ti)B 2 ‒LaB 6 , were fabricated using spark plasma sintering process. (Hf,Zr,Nb,Ti)B 2 ‒LaB 6 exhibits a dual‐phase microstructure, in which (Hf,Zr,Nb,Ti)B 2 is a primary phase with the hexagonal structure and LaB 6 is a secondary phase with a cubic structure. The mechanical properties of both (Hf,Zr,Nb,Ti)B 2 and (Hf,Zr,Nb,Ti)B 2 ‒LaB 6 are comparable, with a combination of high hardness and moderate fracture toughness. Thermal diffusivity and conductivity of (Hf,Zr,Nb,Ti)B 2 are much lower than the individual transition metal borides but are significantly increased by the addition of LaB 6 . Herein, it is implied that the thermal properties of boride ceramics can be controlled through the appropriate design of principal metal element compositions.

In this study, commercial Nd-Fe-B magnets were utilized as starting materials to investigate the impact of various Tb-containing diffusion sources on the magnetic properties. Tb, Tb60Nd5Al30Ga5, and Tb65Pr10Nd5Al5Cu10Ga5 were developed as diffusion sources. After grain boundary diffusion treatment, the magnetic parameters of the magnets were evaluated at 20 °C, 90 °C, and 140 °C. The composition, microstructure, and elemental distributions of the magnets before and after diffusion were examined. It was found that the inherent coercivity of the magnets showed a dramatic increment of 49.4% at 20 °C after diffusion with Tb-containing alloys. The benefits and drawbacks of the designed diffusion sources were thoroughly discussed. Magnets diffused with the Tb65Pr10Nd5Al5Cu10Ga5 source displayed the highest overall performance, generating a thin layer with a grid-like structure at the grain boundaries and a consistent shell structure of Tb around the main phase grains. This work offers a promising alternative in the optimization of Nd-Fe-B magnets.

Novel compositionally complex borides, (Hf,Zr,Nb,Ti)B2 and (Hf,Zr,Nb,Ti)B2-LaB6, were fabricated using spark plasma sintering process. (Hf,Zr,Nb,Ti)B2-LaB6 exhibits a dual-phase microstructure, in which (Hf,Zr,Nb,Ti)B2 is a primary phase with the hexagonal structure and LaB6 is a secondary phase with a cubic structure. The mechanical properties of both (Hf,Zr,Nb,Ti)B2 and (Hf,Zr,Nb,Ti)B2-LaB6 are comparable, with a combination of high hardness and moderate fracture toughness. Thermal diffusivity and conductivity of (Hf,Zr,Nb,Ti)B2 are much lower than the individual transition metal borides but are significantly increased by the addition of LaB6. Herein, it is implied that the thermal properties of boride ceramics can be controlled through the appropriate design of principal metal element compositions.

The additive manufacturing of metal matrix composites (MMCs) using laser powder bed fusion (LPBF) is gaining considerable attention for its ability to produce high‐performance materials with intricate geometries. However, incorporating reinforcement such as diamond (D) particles poses challenges to the melting and solidification behavior of the powders, potentially affecting print quality. In this study, the laser irradiation of AlSi10Mg powder mixed with 5 vol% of uncoated D particles is investigated across varying processing parameters. Dense (97%) and crack‐free parts are successfully produced using high laser powers (300 and 400 W) and low laser scanning speeds (300 and 400 mm s−1). It is shown that the energy needed for proper melting of the powder surpasses that required for printing pure AlSi10Mg. Scanning transmission electron microscopy coupled with energy‐dispersive X‐ray spectroscopy uncovers a direct interfacial reaction between the molten aluminum (Al) and the D reinforcement, forming Al carbide at the Al–D interface. Moreover, Al composites processed under optimal energy density exhibit an enhanced Young's modulus. It is highlighted that optimizing LPBF processing parameters is crucial to achieve superior material properties in MMCs, while controlled matrix–reinforcement interactions offer the potential for tailored properties.

The strength-ductility synergy optimization of refractory high-entropy alloys (RHEAs) faces an intrinsic challenge, creating a fundamental conflict between extreme environment service requirements and room-temperature brittleness, thus severely constraining their engineering applications in advanced manufacturing sectors. NbTa0.5Ti-Alx (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) RHEAs were fabricated via laser powder bed fusion (LPBF) using elemental powder mixtures. To address the challenges of achieving a balance between strength and ductility in RHEAs while leveraging LPBF's capability for near-net shaping of complex geometries. Thermodynamic simulations (CALPHAD and Scheil-Gulliver models) predict that increasing Al content promotes the formation of brittle sigma (sigma) phases, transforming the phase constitution from a single-phase BCC structure to a multiphase equilibrium system. Under the non-equilibrium rapid solidification conditions of LPBF, experimental observations further reveal the formation of ordered B2 phases. Experimentally, LPBF-processed alloys with low Al content (x <= 0.4) exhibit a metastable BCC matrix with nanoscale B2 precipitates, achieving a yield strength of 1047 MPa and >80 % compressive ductility. However, excessive Al (x >= 0.6) induces severe cracking due to thermal stress accumulation and insufficient liquid feeding during solidification, leading to manufacturing failure for x >= 0.8. Microstructural analysis reveals that Al refines substructures and promotes elemental segregation, with Al enrichment at grain boundaries, a co-continuous BCC/B2 nanocomposite in the Al-0.6 alloy, enhancing strength through solid-solution and precipitation strengthening. The hardness increases from 261 HV (Al-0) to 357 HV (Al-0.6) due to lattice distortion and B2 phase formation, while density decreases by 8.8 % (from 8.61 to 7.85 g/cm(3)). This work highlights the critical role of Al in tailoring phase evolution and mechanical properties in RHEAs processed by LPBF. Optimal Al content (x = 0.4-0.6) balances strength and ductility, offering a promising solution for lightweight, high-strength structural applications.

Radiative cooling is an emerging zero-energy-consumption technology for human body cooling in outdoor scenarios during hot seasons. However, existing radiative cooling textiles are limited by low intrinsic cooling power, high hydrophobicity, and heat-insulating properties, which seriously impede a satisfying cooling effect, perspiration-wicking, and heat dissipation, thus limiting human thermal comfort in practical situations. Here, we developed a radiative cooling meta-fabric that was integrated with high perspiration-wicking and thermal conduction capacity. The meta-fabric included a polyoxymethylene (POM) nanotextile on the front side as a selective radiative emitter, a skin-friendly silicone on the reverse side as a thermal conductor, and patterned bamboo yarns (a cellulose fiber derived from bamboo with excellent hydrophilicity) as the water transport channels. As a result, the meta-fabric could rapidly wick away perspiration (within seconds) and had a high thermal conductivity of 1.5 W/(mK), exhibiting high-performance human body cooling with a temperature of 10.9 degrees C lower than the meta-fabric without perspiration. Besides, even without perspiration, the meta-fabric still exhibited a temperature of 9.6 degrees C lower than commercial cotton fabrics. The work provides an alternative method to design smart textiles for personal thermal management in real applications.