Enhancement of the thermoelectric performance of Cu2Se films depends on the synergistic optimization of high power factor and low thermal conductivity. In this study, beta-phase Cu2Se films with order pores of various sizes (100-400 nm) were fabricated using a combination of anodic aluminum oxide template nanoimprinting and vacuum thermal evaporation. The film with 400 nm pores significantly enhanced phonon scattering due to its ordered porous structure, decreasing thermal conductivity. Meanwhile, the (111) orientation and high continuity of film growth suppressed the decrease of electrical conductivity. Thus, the 400 nm porous film has the highest power factor of 1080 mu W & sdot;cm-1 & sdot;K-2 in all the porous films. This value is still lower than that of the non-porous film, however, the porous structure enhances temperature difference and possesses the ability to maintain it. Consequently, the power density of 400 nm porous film enhances by 16.6 % than that of the non-porous film, reaching 5.89 W/m2. This ordered porous architecture established foundation for the development of high-power-density thermoelectric devices.

Although traditional cobalt-based ultra-coarse grained cemented carbides possess both high hardness and toughness, they generally suffer from issues such as abnormal grain growth and cobalt pool segregation, leading to microstructural inhomogeneity that makes it difficult to meet the demanding requirements of extreme working conditions and precision machining fields. High-entropy alloys, by virtue of their multi-principal element characteristics, offer a new approach to overcoming the aforementioned bottlenecks. This study systematically investigates the influence of Cr content and the addition amount of HEAs on the microstructure and mechanical properties of ultra-coarse grained cemented carbides, and further elucidates the underlying mechanism governing WC grain growth in the presence of HEA binders. The results demonstrate that with increasing Cr content in the HEA binder, the average WC grain size gradually decreases, accompanied by a notable decline in relative density and hardness, whereas the fracture toughness remains relatively unchanged. Notably, the ultra-coarse grained cemented carbide fabricated with a 10 wt.% addition of the CoCuFeNiCr0.5 HEA binder exhibits the optimal comprehensive mechanical performance, achieving an average WC grain size of 6.12 μm, a relative density of 95.47%, a Vickers hardness of HV30 1188.77, and a fracture toughness of 22.85 MPa·m1/2.

The present study investigated the effect of ausforming with different strains on the subsequent bainitic transformation in a low-carbon steel. The results revealed that the equilibrium volume fraction of bainite increased from 47% to 76%, with an ausforming strain of 30%, during which 30% bainite was formed during deformation. Both the bainite formed during deformation and subsequent isothermal holding were significantly refined due to the ausforming process. Furthermore, the enhanced bainitic transformation promoted carbon redistribution into the austenite and thus increased the volume fraction of retained austenite. The refined bainite structure and the stabilized retained austenite with a higher volume fraction achieved synchronous improvement of strength and plasticity.

Compared with conventional cemented carbide, ultrafine gradient cemented carbide exhibits higher hardness, toughness, and wear resistance, together with better crack resistance under high temperature and high-pressure cutting conditions. However, most studies on coated cutting tools have focused on conventional cemented carbide substrates, while studies on the compatibility between ultrafine gradient cemented carbide substrates and different coatings, as well as their cutting performance, remain limited. In this study, single-layer AlTiSiN, AlCrTiN, and multilayer CrAlTiN coatings were deposited on ultrafine gradient cemented carbide substrates using arc ion plating. Cutting experiments combined with finite element simulations were conducted to analyze tool wear behavior and temperature distribution during high-speed turning of Ti-6Al-4V alloy. The results indicate that the AlCrTiN coating shows better compatibility with the substrate than AlTiSiN and multilayer CrAlTiN coatings, exhibiting superior cutting performance. When the cutting length was below 575 m, the flank wear was approximately 0.1 mm. The error between experimental and simulation results was less than 20

High-entropy alloys (HEAs) have attracted increasing attention as alternative binder phases for WC-based cemented carbides. However, precipitation during sintering is unavoidable in HEA binders, and the role of precipitated phases in microstructural evolution and mechanical performance remains insufficiently understood. In this work, the precipitation behavior in WC-15Cox FeNiCrCu ( x = 0.5, 1, 1.5, 2) cemented carbides was systematically investigated, clarifying the mechanism of precipitate contributions to mechanical properties. Cr was identified as the primary precipitating element, separating from the HEA binder and oxidizing to form Cr2 O3 owing to strong oxygen affinity. The Cr2 O3 precipitates form coherent interfaces with the reaction layer (Co,Fe)3 W3 C, generated at the WC/HEA interface, exemplified by the orientation relationship (012)Cr2 O3 //(1 3 & strns; 1 & strns; )(Co,Fe)3 W3 C ( delta = 1.1%), which markedly enhances interfacial bonding. In addition, numerous ductile [CoFeNiCu] nanoparticles are distributed within the Cr2 O3 regions, effectively mitigating the intrinsic brittleness of the oxide phase. As a result, the cemented carbides with HEA binder achieve an exceptional combination of ultrahigh hardness without losing fracture toughness. The WC15HEA (Co0.5) reaches a maximum hardness of 2035.4 kgf/mm2 together with a fracture toughness of 13.05 MPa m1/2 . This work provides new insights into the design of cermet through controlled precipitation and interface engineering in HEA binder. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Ultra-coarse grained cemented carbides exhibit high toughness but relatively low hardness. Traditional cobalt-based binder phases cannot balance these two properties. High-entropy alloys (HEAs), as novel binders, leverage high-entropy effects and solid-solution strengthening to enhance hardness while preserving toughness. They also improve binder distribution uniformity and eliminate cobalt pool segregation. In this study, a series of CoCuFeNiCrₓ (x = 0.5, 1.0, 1.5, 2.0) high-entropy alloy binders were prepared by mechanical alloying, and ultra-coarse grained WC-HEA cemented carbides were fabricated via vacuum sintering. The effects of Cr content and HEA addition amount on the microstructure and mechanical properties were systematically investigated. With increasing Cr content in the HEA binder, the following trends are observed. The average WC grain size gradually refines from 6.12 μm to 5.53 μm. The relative density decreases from 95.47% to 88.91%. The fracture toughness decreases from 22.87 MPa·m¹/² to 21.34 MPa·m¹/². The hardness increases from HV30 1189.30 to HV30 1260.50. These changes reveal a trade-off between hardness and toughness. The ultra-coarse grained cemented carbide fabricated with 10 wt.% CoCuFeNiCr₀.₅ HEA binder exhibits the optimal comprehensive mechanical performance. It shows an average WC grain size of 6.12 μm. Its relative density is 95.47%. Its Vickers hardness is HV30 1188.77. Its fracture toughness is 22.85 MPa·m¹/². Sluggish diffusion in the HEA and Cr-induced inhibition govern grain growth. This study reveals how Cr content controls densification, grain size and properties, providing a strategy to balance strength and toughness in ultra-coarse cemented carbides by designing HEA binders.

An amorphous-nanocrystalline dual-phase multilayer structure was designed to overcome the columnar grain structure of high-entropy nitride coatings by regulating the structural evolution of TiAlTaCrZr/(TiAlTaCrZr)N multilayers with different modulation periods and ratios. Compared with the monolithic (TiAlTaCrZr)N coating, the multilayer coating exhibits a maximum toughness improvement of 38.9% while maintaining a low wear rate of 1.987 × 10−6 mm3·N−1·m−1. In a 3.5% NaCl solution, the corrosion current density decreases from 3.186 × 10−7 A·cm−2 to 6.75 × 10−8 A·cm−2. The amorphous TiAlTaCrZr layer suppresses the V-shaped growth of columnar grains in the high-entropy nitride layer and promotes significant grain refinement through interface-mediated growth regulation. The restriction of dislocation motion by grain boundaries, together with the strengthening effect arising from refined grains, synergistically enhances the toughness of the coating without compromising its hardness. In addition, the abundant grain boundary interfaces and the disordered structure of the amorphous layer effectively hinder the diffusion of oxygen atoms and corrosive ions, thus enhancing the oxidation resistance and corrosion resistance of the coating. This study provides a novel materials design strategy for high-performance protective tool coatings.

The integration of machine learning (ML) into materials science has introduced a transformative approach for predicting complex material behavior, particularly in systems where traditional modeling methods face significant limitations. Bulk metallic glasses (BMGs), characterized by their amorphous atomic structure, exhibit unique mechanical properties such as high strength and elastic limit, yet their deformation behavior remains difficult to predict due to the absence of conventional dislocation mechanisms. This study explores the application of data-driven machine learning techniques to model and predict the flow curve and deformation behavior of BMGs under varying conditions. By utilizing experimental datasets that incorporate parameters such as temperature, strain rate, and alloy composition, ML models-including neural networks and support vector machines-are trained to capture nonlinear relationships between input variables and mechanical response. The results demonstrate that ML-based models can accurately reproduce stress-strain behavior and outperform traditional empirical approaches in predictive capability and generalization. Furthermore, the study highlights the advantages of ML in reducing experimental costs and enabling rapid exploration of material design spaces. However, challenges related to data quality, model interpretability, and integration with physics-based frameworks are also discussed. The findings underscore the potential of machine learning as a powerful tool for advancing the understanding and design of amorphous materials, paving the way for future innovations in materials engineering.

Porous structures can enhance thermoelectric films by suppressing heat transport, but excessive porosity degrades electrical conduction. Here, (3-Cu2-xSe films with four pore architectures (non-pore, through-pore, half through-pore and sealing-pore) were grown on AAO templates by tuning the thickness. The sealing-pore film combines internal pores with a dense surface layer, which blocks heat flow while providing continuous carrier pathways. As a result, at 250 degrees C it yields a power factor of about 460 mu W center dot m-1 center dot K-2 and a maximum power density of 0.58 W center dot m-2, where the maximum power density is nearly twice that of the non-pore film prepared under the same conditions. These results show that sealing-pore structure can balance thermal insulation and electrical transport, offering a simple method for high-performance Cu2-xSe TE films and devices.

Precise control of non-metallic inclusions is essential for achieving the desired mechanical properties of steels. Generally, fine inclusions are relatively difficult to remove completely during the refining process. They can serve as the heterogeneous nucleation sites for the formation of intragranular ferrite (IGF). This interlocked microstructure is the preferred type in the coarse-grain heat-affected zone of weldments to improve the toughness at low temperatures. In this study, two representative grades of low-alloy steels with 0.2 and 0.4 pct carbon were used to investigate the synergistic influence of the prior austenite grain size (PAGS) and cooling rate on IGF formation. In-situ observation experiments using high-temperature confocal laser scanning microscope, thermodynamic calculations and electron microscopy characterizations were used to investigate this synergistic effect in the two steel grades. It is found that the coarse grains can promote IGF nucleation and growth at an intermediate cooling rate, while smaller grain size requires a higher cooling rate as a driving force for IGF formation. This synergistic effect was verified in the steels with 0.2 and 0.4 pct carbon. The current work provides a quantitative study on the comprehensive influence of PAGS and cooling rate on IGF formation. The obtained findings are validated for general low-alloy steels with different carbon contents, contributing to the development of the ‘Oxide Metallurgy’ concept.

The coarsening behavior of solid particles significantly affects the alloy microstructure during semi-solid manufacturing. The effects of high magnetic fields (HMFs) on solute diffusion and interfacial energy hold promise for controlling coarsening behavior. In this work, the Al-30 wt% Cu alloys, whose coarsening process is dominated by solute diffusion, was selected and subjected to semi-solid isothermal annealing in 560 degrees C for various times without and with a 6 T magnetic field. The effect and mechanism of high magnetic fields on the coarsening behavior of alpha-Al particles were investigated. Quantitative microstructure analyses revealed that the coarsening process was suppressed while the particle sphericity was improved. Coarsening kinetics calculations showed that the coarsening exponent n is 3.34 at 0 T and 3.40 at 6 T, indicating that the coarsening process remains diffusion-controlled throughout. However, the coarsening rate constant K decreased from 11.24 & times; 10(-20) m(3)& centerdot;s(-1) at 0 T to 9.88 & times; 10(-20) m(3)& centerdot;s(-1) at 6 T. The high magnetic field not only suppressed the long-range diffusion of Al solute in the liquid matrix but also inhibited the local diffusion of Cu solute rejected from the particles, leading to the formation of a Cu-rich layer around the particles that hindered the entry of Al solute into the particles. The diffusion coefficient of the coarsening system decreased by 58% at 6 T. Meanwhile, the high magnetic field increased the interfacial energy of the particles, which was insufficient to compensate for the substantial reduction in the diffusion coefficient yet, the coarsening behavior remained suppressed. Nevertheless, the increased interfacial energy amplified the free energy difference arising from curvature variation, driving the particles toward a more regular spherical shape and thus improving their sphericity. Notably, the enrichment of Cu solute around the particles resulted in the formation of a similar to 40 nm thick transition layer consisted of Al and intermetallic compounds (Al2Cu and eta(1)) surrounding the particles. This may become a new method for preparing core-shell structured materials under magnetic fields. This work demonstrates that high magnetic fields can effectively regulate coarsening behaviors through combined modulation of solute diffusion and interfacial energy, offering new strategies for microstructural design in semi-solid processing.

The solution-strengthened GH3536 superalloy fabricated via laser powder bed fusion (LPBF) possesses inherent anisotropy, which restricts its industrial application. Herein, two heat treatment routes, namely HIP (Hot Isostatic Pressing) + double aging (HA) and HIP + solution + double aging (HSA), were adopted to investigate their effects on the mechanical anisotropy of LPBF-built GH3536 along and perpendicular to the building direction. The results show that HA treatment remarkably enhances the tensile strength of horizontal specimens but fails to eliminate anisotropy. In comparison, the HSA treatment induces columnar-to-equiaxed grain transformation and tailors' carbide precipitation morphology, thereby effectively alleviating the alloy anisotropy. After HSA treatment, the room-temperature tensile strength reaches 800 MPa along with an elongation of 40%. This study clarifies the anisotropy evolution mechanism and provides a theoretical basis for heat treatment optimization of LPBF nickel-based superalloys.

By combining spark plasma sintering and gradient sintering, low-melting-point nanocrystalline gradient cemented carbides were prepared by adding Ni and Fe to the binder phase. With a decrease in the melting point of the cemented carbides, the diffusion coefficient of V atoms increased and the thickness of the gradient layer increased. In the case of the WC-CoNiFe-4V(C, N) alloy, the thickness of the gradient layer increased by 50 % (with a maximum thickness of 105 +/- 4 mu m) as compared to that in the case of the WC-Co-4V(C, N) alloy. The Co content of the gradient layer of the WC-CoNiFe-4V(C, N) alloy reached more than 20 wt%, which is about twice the total amount of the binder phase. A new method is provided for developing cemented carbides with thicker gradient layers.

The inherent high hardness and low fracture toughness in WC-Co cemented carbides fundamentally restricts ability to fully utilize the advantages of dual-phase materials. This study demonstrates an interfacial engineering design strategy to concurrently refine WC grains and strengthen WC/Co interfacial bonding, achieving synergistic enhancement of hardness and fracture toughness. The results show that added Ti(C, N) reconfigures the conventional WC/Co interfaces into two reinforced interfaces, WC/Ti(C, N) and Co/Ti(C, N). Ti(C, N) acts as heterogeneous nucleation sites, inducing the nucleation of Co and promoting its growth along the same crystallographic orientation. The identical FCC crystal structure and orientation establishes a high density of coherent Co/Ti(C, N) interfaces, which significantly enhances the interfacial bonding between Co and Ti(C, N). WC/Ti(C, N) interfaces develop similar to 2 nm thick (W, Ti)(C, N) complexion layers via dissolution-reprecipitation mechanisms, effectively resolving the inherent HCP/FCC (hexagonal close-packed/face-centered cubic) mismatch and improving interfacial fracture resistance. The dual-interface optimization promotes transgranular fracture dominance at binder interfaces, increasing energy dissipation during crack propagation. The Ti(C, N)-added WC-Co nanocrystalline cermet achieves synergistic property enhancement with a Vickers hardness of 2110.68 HV30 and fracture toughness of 11.31 MPam(1)(/)(2), representing 13.07 % and 1.71 % improvements respectively compared to conventional WC-Co cemented carbides. This work demonstrates that targeted interfacial design can overcome the traditional hardness-toughness trade-off in ceramic-metal composites, providing new insights for optimizing cemented carbides in extreme mechanical applications.

Cordierite-based composites with pin rod SiC were successfully prepared by using industrial powder of coal gangue, Al2O3 and MgO as the main raw materials and incorporating varying proportions of SiC and sintering in air at 1350 degrees C through a vacuum freeze-drying method. The effects of SiC content on the phase composition, microstructure, mechanical properties and thermodynamic properties of samples were discussed. With the addition of SiC, pin rod SiC fibers were formed in the samples and a cross-interlocked three-dimensional mesh structure was established together with the cordierite matrix. The better thermal conductivity of SiC itself and the formation of this structure led to an increase in the thermal conductivity and bending strength of the samples, optimizing the properties of the cordierite material. The results showed that the sample with 75 wt% SiC addition had the best performance. At this time, the thermal conductivity of the sample was 5.64 W/mK, the bending strength was 4.12 MPa. In addition, the filtration capability can be improved by SiC fiber growth on the wall of composite honeycomb ceramics, which combined with the cross-interlocked three-dimensional mesh structure formed, gives it great potential as a diesel particulate filter.

Al-15 wt% Cu binary alloys were isothermally annealed in a semisolid state with and without a 10 T magnetic field. The influence of the magnetic field on the 2D morphology and 3D distribution of alpha-Al grains was investigated. The coarsening mechanism under a high magnetic field was proposed based on microstructural analysis, coarsening kinetics calculations, and interfacial energy calculations. The size of the alpha-Al grains was increased, and the coarsening rate was significantly accelerated by the magnetic field. Meanwhile, more alpha-Al grains contacted each other and started coalescing. The grain size distribution revealed that the coarsening mechanism shifted from Ostwald ripening at 0 T to a combination of the Ostwald ripening and migration-coalescence at 10 T. The accelerated coarsening rate may be attributed to an increase in interfacial energy from 0.143 to 0.213 J m-2 under the high magnetic field. Significant Cu clustering was observed between coalesced grains at 10 T, which could further demonstrate the accelerated coarsening rate. Additionally, the magnetic field induced the rotation of adjacent grains via magnetic torque, reducing their misorientation and subsequently enhancing their coalescence. This study elucidated the mechanism of orientation-induced grains coarsening under a high magnetic field, providing a novel methodology for controlling metallic materials fabrication processes which undergo grains coarsening using magnetic fields.

Ni-P electroless coatings are widely utilized in industrial applications due to their exceptional hardness and wear resistance. To enhance the wear resistance of Ni-P coatings and reduce the wear of counterparts, a Ni-P-MSH composite coating was fabricated successfully through the incorporation of environmentally friendly magnesium silicate hydroxide (MSH) nanoparticles. This study demonstrates that MSH significantly influences the hardness, crystal structure, and chemical composition of the Ni-P coating, offering a novel approach to performance enhancement. Results show that the wear rate of Ni-P-MSH1 composite coating decreases by about 82.9% compared with the Ni-P coating, with its wear resistance comparable to that of the heat-treated Ni-P-AT300 coating with high hardness. Furthermore, the steel ball sliding against the Ni-P-MSH1 coating exhibited a wear rate three orders of magnitude lower than that observed with the Ni-P-AT300 coating, highlighting the excellent lubrication performance of the Ni-P-MSH1 coating. The outstanding wear resistance of Ni-P-MSH composite coatings can be attributed to the formation of a tribofilm composed of nickel oxide and phosphate on the surface of the coatings, and this discovery lays a foundation for the development of high-performance and eco-friendly coating materials.

The electromagnetic swirling flow in nozzle (EMSFN) technique is designed to mitigate the adverse effects of unstable and uneven flow within the submerged entry nozzle in continuous casting. Utilizing electromagnetic forces, EMSFN stabilizes the flow within the nozzle, leading to a more controlled flow in the mold. Numerical simulations were used to quantitatively analyze the magnetic and flow fields in a slab continuous casting system under EMSFN. Results indicate that EMSFN significantly stabilizes the outflow from the nozzle, with stability increasing with higher current intensity. At 10,000 Ampere-turns (At) of the coil, meniscus fluctuations were unstable. They stabilized at 13,000 At, with minimal changes observed beyond this point. The optimal current intensity for stable mold flow, at a casting speed of 1.56 m/min, is 13,000 At. These findings confirm the effectiveness of EMSFN in stabilizing the internal flow field of the slab mold and determining optimal operational current intensity.

Joule-Brayton cycle-based pumped-thermal electricity storage can develop from a pure electricity-storage function to integrated cooling, heating and power systems. Cascaded latent-heat stores are promising as thermal stores that offer flexible multi-grade heat and cold utilisation. So far, comprehensive investigations of these stores for pumped-thermal electricity storage, particularly through the lens of the second law of thermodynamics, have not been investigated comprehensively. This paper presents a model for cascaded latent-heat stores, and assesses the impacts of tube-side velocity, total stage number and stage area on the exergy performance for the entire store and individual stages. A comparative analysis highlights that the upper limit of roundtrip exergy efficiency in combined heating and power mode surpasses pure electricity-storage mode by 2.1%. Furthermore, cascaded latent-heat stores demonstrate comparable performance to packed-bed and liquid sensible-heat stores in terms of exergy metrics. Notably, in combined heating and power mode, cascaded latent-heat stores improve the upper limit of roundtrip exergy efficiency by 7.5% over packed-bed heat stores. The second-law analysis yields more refined store designs than first-law assessments.