Carbide precipitation and ferrite formation often occur in 304-type austenitic stainless steels due to insufficient austenite stabilities. Based on the 16-atom formula for 304 grades derived from the cluster formula approach, the present work explores the optimal Cr and Ni balance and relevant C contents by considering the sensitization tendency in alloy series (Cr3.0Si0.125)-(Ni1.625Mn0.25)-Fe-11-(Cr23/6C)(0.0125 similar to 0.0625) and (Cr2.7 similar to 3.1Si0.125)-(Ni1.625Mn0.25)-Fe-11.3 similar to 10.9-(Cr23/6C)(0.0625), or (17.0 similar to 19.4)Cr-10.7Ni-1.5Mn-0.4Si-(0.02 similar to 0.08)C in wt.%. These alloys are arc-melted and copper-mold cast into 30g ingots. Upon sensitizing (650 degrees C/1h/furnace cooling), both M23C6 and ferrite are the least present in alloys featuring Cr and Ni equivalents of 19.2 similar to 20.0 and 13.5 similar to 13.9. Under the confinements from the above equivalents and from the ASTM standard, fairly high C contents are necessary for 304-type of steels, (0.05 similar to 0.07)C for 304, (0.05 similar to 0.10)C for 304H, and (0.02 similar to 0.03)C for 304L. Stainless steels complying to the optimal Cr-eq and Ni-eq ranges satisfy a Ni/(Cr-2) ratio range of 1 similar to 2 in terms of 16-atom formula.

High-entropy oxides (HEOs) have emerged as a novel class of materials in recent years. By deviating from conventional material design paradigms, the high-entropy strategy leverages multi-element synergistic effects, opening up new research directions in materials science. As anode materials, HEOs show great potential to overcome the performance limitations of traditional anodes in lithium ion battery and offer new opportunities for the design of advanced electrochemical energy storage systems. This review summarizes recent progress in the development of HEO-based anodes, with a focus on the driving forces behind their phase stability, the influence of cationic composition, and underlying mechanisms for performance modulation. Additionally, it outlines future prospects, application challenges, and modification strategies for three common HEOs structures: rock salt, spinel, and perovskite.

Developing additively manufactured α + β Ti alloys for service at 600 °C remains a challenge due to the strength-ductility trade-off associated with coarse parent β grains and fully lamellar microstructures. Here we report an α + β Ti-6.5Al-2V-2Mo-1Nb-14Zr (wt%) alloy previously designed by the cluster formula approach. Its high Zr content enhances constitutional undercooling, promoting the formation of equiaxed parent β grains during 2 kW laser additive manufacturing. Subsequent solution treatment and aging yield a bi-lamellar microstructure comprising coarse primary α laths (1.37 μm in width) and fine secondary α precipitates (0.13 μm in width). This tailored microstructure delivers unprecedented tensile properties at both room temperature and 600 °C: ultimate tensile strength of 1249 MPa with 9.3% elongation at room temperature, and ∼769 MPa with 28.2% elongation at 600 °C, surpassing conventional high-temperature Ti alloys. The enhanced ductility originates from activated pyramidal slip in the primary α laths, while the excellent strength is attributed to the synergistic contributions of grain boundary strengthening, solid-solution strengthening, and aging-induced α₂ (Ti3Al) precipitation. This work demonstrates an effective strategy for designing advanced additively manufactured Ti alloys through simultaneous control of parent β grains and α phase.

Multi-component carbide ceramics have garnered significant attention as ultra-high-temperature structural materials due to their exceptionally high melting points and excellent mechanical properties. In this work, we systematically investigate the synergistic effects of C vacancies and Ti alloying on the thermodynamic stability and elastic behavior of (Zr, Ti)C-x carbides using first-principles calculations. Specific cluster structural models of [C-M-6](C,square)(5) (M = Zr/Ti, square = vacancy) were constructed by considering the local chemical short-range orders of elemental distribution and the ordering of vacancies on C sublattice, which were then employed as inputs for first-principles calculations. The results reveal that the introduction of C vacancies decreases the free energy at high temperatures and enhances the thermodynamic stability, whereas Ti substitution for Zr tends to reduce stability. Notably, the ternary carbide Zr5Ti1C5 ([C-Zr5Ti1](C,square)(5)) with an equimolar ratio of Ti-to-vacancy exhibits superior high-temperature thermodynamic stability. Analysis of entropy contributions indicates that both vacancies and Ti addition primarily alter the free energy by modifying the lattice vibration modes, an effect dominated by the vibrational entropy. These two types of defects weaken the M-C bond strength, resulting in reduced binding energy and Young's modulus. Furthermore, this synergistic effect considerably lowers the critical temperature required to stabilize the single-phase solid solution structure in multi-component carbides, which is attributed to a decrease in mixing enthalpy and an increase in configurational entropy caused by vacancies. The cluster-model-embedded first-principles approach offers valuable insight for designing high-performance carbides in complex ceramic systems.

High-temperature adhesive wear at self-mated contacts in nickel-based superalloys constitutes a persistent reliability barrier for critical dynamic components such as bearings and turbine rotors. In this work, copper alloy films combining excellent compatibility with nickel substrates, microstructural stability at elevated temperatures, and inherent self-lubricating properties were deposited on Inconel 718 (In718) via radio-frequency magnetron sputtering. The films composed of a face-centered cubic Cu-based solid solution and coherently precipitated L12-Ni3Al nanophases exhibit strong metallurgical bonding to the substrate, and their hardness is synergistically regulated by grain size, residual stress, and precipitates. Tribological tests show that the films significantly reduce the wear rate at both room temperature and 800 degrees C, whether sliding against In718 or Al2O3 ball. Particularly under self-mated conditions, the films reduce the wear rate by up to 38.4% at room temperature and decrease the counterpart wear scar diameter by 48.4%. At 800 degrees C, through the formation of a CuO-rich lubricating transfer layer, the wear rate under self-mated sliding is further reduced by 76.8%, with a 51.8% reduction in the counterpart wear scar diameter. The outstanding wear-resistant performance is attributed to the strengthening and toughening effects of nano-twins/stacking faults, the synergistic load-bearing capacity of the soft Cu matrix and hard Ni3Al precipitates, and the friction-induced formation of a Cu-based oxide lubricating layer. This study provides a promising coating strategy to mitigate high-temperature adhesive wear at self-mated interfaces of nickel-based superalloys and offers a theoretical basis for the design of self-lubricating films under extreme conditions.

Cu-Ni-Co-Si alloys are widely used in electrical and electronic applications owing to their superior mechanical properties, high electrical conductivity and favourable formability. To address the trade-off between strength and conductivity in conventional processes, this study optimized the solution and ageing regimes using in situ hightemperature hardness, conductivity and X-ray diffraction measurements. When held at 1000 degrees C for 5 h, the in situ hardness stabilised at 12 HV. Treatment at 450 degrees C for 2 h yielded optimal properties, including an in situ hardness of 95 HV, conductivity of 24.7% IACS and a dislocation density of 13.15 & times; 1014 m-2. The optimized alloy exhibited uniformly dispersed nano-sized (Ni, Co)2Si precipitates, forming a coherent interface with the Cu matrix, achieving favourable strength-conductivity synergy. In situ conductivity analysis was used to establish kinetic equations at 450 degrees C: sigma 450 degrees C= 0.2006 + 0.0099 ln t (conductivity vs. ageing time) and f450 degrees C= 56.5794 + 5.1476 ln t (precipitation vs. time), consistent with experiments. Precipitation strengthening played a crucial role, accounting for 60.7% of the total strength. This optimized single-stage heat treatment streamlines production and enhances performance, providing a viable material solution for high-end electrical applications.

With the transformation of the global energy structure, there is an urgent need to develop new types of low-cost, high-capacity and long-cycle lithium-ion batteries (LIBs) cathodes. Among the most promising candidates for high-energy-density LIBs, lithium-rich manganese-based oxide (xLi2MnO3·(1-x)LiMO2, LRM, M represents transition metal) cathodes have attracted extensive research interest due to their exceptionally high specific capacity and energy density. However, the practical application of LRM is hindered by several critical challenges, including voltage decay, oxygen release, and structural phase transitions. This review systematically summarizes the latest research progress on the crystal structure and electrochemical reaction mechanisms of LRM. Key modification strategies are critically analyzed, including composition optimization, surface/defect engineering, ion doping, and the emerging high-entropy oxides design strategy. A comparative evaluation of the influence of various synthesis methods on the electrochemical performance is presented. Finally, the future development and commercial prospects of LRM are discussed, aiming to provide insights for advancing their practical application.

Bentonite is introduced for the first time to activate spontaneous hydrogen generation via aluminum hydrolysis under ambient conditions. The aluminum-based composite 90Al-6.5Bentonite-3.5Bi, wt.% was prepared through powder pressing and sintering at 650 °C under an argon atmosphere. This sample reacts with pure water within 1 s across a temperature range of 0 °C to 30 °C (approximate temperatures), achieving a 100% hydrogen conversion yield at 20 °C. The maximum hydrogen production reaches 1389.59 mL g−1 at 30 °C. The bentonite-activated hydrogen generation in air and at room temperature greatly facilitates the application of hydrogen energy in mobile scenarios.

Interstitial filling with non-metallic small atoms (SAs) provides a crucial pathway for tuning the structure and properties of high-entropy films. Owing to their small atomic size, SAs preferentially occupy interstitial sites and, through their distinct chemical interactions with constituent metallic elements, induce changes in local chemical order (LCO). With increasing SAs content, high-entropy films exhibit a progressive transition from disordered interstitial solid solutions to locally ordered states, and eventually to ordered crystalline or amorphous structures, accompanied by pronounced property variations. Accordingly, this review focuses on high-entropy films and systematically summarizes the effects of SAs filling on crystal structure, LCO, and mechanical, magnetic, and electrical properties. A percolation-theory framework is introduced, in which different LCO types are treated as percolating units with characteristic properties, thereby establishing intrinsic correlations between LCO content and macroscopic property evolution. On this basis, the commonalities and distinctions among different SAs in regulating material properties are summarized and compared. Finally, an outlook on future research directions is provided.

Dual-phase Ti alloys, recognized for excellent mechanical properties and processability, cannot withstand service temperatures above 500 degrees C. In this paper, a dual-phase alloy Ti-6.5Al-2V-2Mo-1Nb-14Zr-0.1Si (DT600) is developed, whose high-temperature performance is comparable to those of prevailing near-alpha 600 degrees C Ti alloys. The composition design follows the composition formula {Al2Ti14}(12)+beta-{Al1V2Ti15}(5) of popular dual-phase Ti-6Al-4V, via enhanced Al, partial replacement of V by stronger beta stabilizers Mo and Nb, and additional silicide formers Zr and Si, into alpha-{(Al,Si)(2)(Ti,Zr)(14)}(12)+beta-{Al-2(Mo,Nb,V)(2)(Ti,Zr)(14)}(5). 80 g ingots of DT600 and Ti-6Al-4V were prepared by arc melting and copper mold casting, followed by annealing at 700 degrees C for 2 h. Due to fine silicide precipitation (similar to 50 nm) and basket-weave alpha lamellar (similar to 260 nm) microstructure, its tensile properties at room temperature (R-m = 1321 MPa, R-p0.2 = 1242 MPa, and A = 5.2%) are superior to the reference Ti-6Al-4 V alloy (1004 MPa, 855 MPa, and 6.1%). Most importantly, this alloy achieves an unprecedented level of 600 degrees C tensile performance (739 MPa, 623 MPa, 46.2%), approaching the strength level of prevailing high-temperature near-alpha IMI834 grade, with much enhanced plasticity. The microstructure mechanism behind such superb performance is fully discussed. The development of DT600 demonstrates the usefulness of the cluster formula approach in accurate composition design of high-temperature Ti alloys.

Titanium dioxide suffers from poor conductivity and low capacity, whereas tin dioxide is hindered by low initial Coulombic efficiency and severe volume expansion, limiting their direct use as anodes for lithium-ion batteries. In this paper, single-phase rutile-structured Ti18Sn18Nb3Ta3Cr6O96 was designed and synthesized by the clusterplus-glue-atom model and solid-state reaction method. When evaluated as the lithium-ion battery anode, this material demonstrates superior electrochemical performance over all other synthesized counterparts. It achieved a high reversible capacity of 200 mAh g(-1) after 100 cycles at 100 mA g(-1), along with significantly improved cycling stability and rate capability relating to its optimized Nb/Ta/Cr concentration within Ti/Sn matrix and single-phase characteristic. Ti18Sn18Nb3Ta3Cr6O96 effectively suppresses the grain growth of nano-Sn-structured domains with particle size of 4-6 nm. These fine domains significantly alleviate volumetric strain during lithiation/delithiation, eliminate microscopic dislocation defects, and prevent macroscopic crack initiation in the electrode during cycling. Overall, this study offers a novel design strategy for rutile-structured medium-entropy oxides and demonstrates their promising potential for high-performance energy storage applications.

Conventional Ti alloys strictly limit the content of Al and Si to avoid ductility loss caused by the precipitation of intermediate phases, which in turn restricts the further enhancement of their ambient and high-temperature properties. This study proposes an innovative strategy based on precise composition design via the cluster formula approach, coupled with subsequent heat treatment to control intermediate phases. Starting from the cluster formula of Ti-6Al-4V, α-{Al2Ti14}12+β-{Al1V2Ti14}5, the composition was modified by increasing Al to promote α₂-Ti₃Al precipitation, adding Zr and trace Si to form silicides, and substituting V with a refractory-element (Mo₀.₅Nb₀.₅Ta₀.₅W₀.₅) to refine α lamellae. The prepared alloy, after solution treatment at 840 °C for 1 h and aging at 600 °C for 4 h, exhibits a multimodal microstructure consisting of equiaxed α (αe), lamellar α (αl), and secondary α (αs). A hierarchically distributed, multi-scale precipitate structure is observed: sub-micron silicides and nano-sized Ti3Al are preferentially located in the primary α phase, while secondary nano-silicides are uniformly dispersed within the βt matrix. The alloy achieves an ultra-high strength level at ambient temperature (Rm = 1496 MPa, Rp0.2 = 1446 MPa, A = 7.8 %) and retains a tensile strength of 695 MPa at 600 °C, comparable to that of typical near-α high-temperature Ti alloys such as IMI 834. This study successfully realizes the controlled precipitation of strengthening phases and microstructural refinement through cluster-formula based design, providing a novel pathway for developing Ti alloys with outstanding performance at both ambient and high temperatures.

The multi-component compositional characteristics of high-entropy systems provide the potential to introduce complex inter-component interactions, which can purposefully alter the local structure and generate diverse valence states, paving the way for promising applications in catalysis, energy storage, and sensors. In this paper, the transition metal (TM) element Cu, known for its strong negative enthalpy of mixing with the basic components, and the non-metal element O, which has a large electronegativity difference, are introduced into the TaNbHfZr films. The effects of mixing enthalpy and electronegativity on the local structure are investigated by comparing the microstructure, surface potential, native oxidation, and hardness of the films. The cluster-formula of TaNbHfZr-Cu-O films is further resolved using the cluster-plus-glue-atom model, revealing the mechanism by which the added elements alter the local structure and induce multivalent states. Moreover, the cause of the hardness change is explained by the results of the local structure change, which increases the credibility of the theory. It has been demonstrated that the introduction of Cu under oxygen-free conditions leads to an increase in high-density "clusters with Cu", causing localized structural fluctuations at the nanoscale. The addition of O serves to attenuate the effect of Cu, thereby homogenizing the potential distribution. Differences in electronegativity between components lead to inhomogeneous filling of O in cluster vacancies, resulting in TM valence states that can fluctuate between +1 and + 4 or +5. The study not only demonstrates the feasibility of introducing multivalent states in the TaNbHfZr system but also theoretically estimates the fluctuation amplitude of oxygen density in the films at the angstrom level, further correlating the fluctuations in valence with those in O density. This provides a theoretical basis for a deeper understanding of the effect of composition on the local structure of high-entropy alloy films and for the purposeful use of multivalent states to enhance properties of material.

Carbonate molten salts exhibit higher operating temperatures and greater thermodynamic efficiency than nitrates; however, they also possess stronger oxidizing capacity, which exacerbates corrosion and compromises material durability. Heat-resistant Cu-Ni-Al alloys are promising candidates for sealing and drive-train components in molten salt systems due to their good microstructural stability and oxidation resistance. This study presents the first application of the Cu75Ni18.75Al6.25 (at.%) alloy in high-temperature carbonate salt environments. Furthermore, two novel alloys, Cu71.86Ni12.5Al4.69Co4.69Fe3.29Ti1.56Cr0.94Zn0.47 and Cu75Ni12.5Al4.69Co3.125Fe2.1875Ti1.56 Cr0.625Zn0.3125, were developed and fabricated using a cluster formula compositional design approach. All three alloys exhibited surface-limited oxidation with intact oxide scales after 504 h of continuous exposure at 650 degrees C. The multicomponent alloys demonstrated significantly lower mass losses (12.96 and 21.18 mg/cm2) and corrosion rates (0.27 and 0.44 mm/year) compared to the Cu75Ni18.75Al6.25 (42.46mg/cm2 and 0.88 mm/year), indicating the considerable potential of these alloys for use in corrosive molten salt environments. Mechanistic analyses reveal that three primary mechanisms contribute to the superior performance: (i) a high volume fraction of finely dispersed gamma' phase, which promotes early and stable Al2O3 formation; (ii) multielement segregation at grain boundaries that suppresses intergranular oxidation; and (iii) enhanced solute interactions within the gamma/gamma' phases, which reduce elemental diffusion. These findings provide clear insights into the corrosion behavior of Cu-Ni-Al-based alloys in carbonate molten salts and offer valuable guidance for the development of high-performance materials suitable for demanding environments. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Due to the inherently high degree of alloying in Cu–Ni–Al alloys, they are prone to casting defects such as porosity and microstructural coarsening during solidification. These issues compromise the reliability and service life of the alloy under practical operating conditions, limiting its engineering applications. On the basis of the demand for high-temperature material performance in practical engineering applications, this work systematically examines the effects of trace boron (B) addition on the microstructure, mechanical performance, in situ softening resistance, and tribological properties of Cu–Ni–Al alloys. Alloy samples were prepared via high-purity argon-shielded vacuum induction melting, followed by tailored heat treatment. Through microstructural characterization and property evaluation, it was found that the addition of 0.008 wt% B significantly suppressed the number of casting defects (the average equivalent diameter decreased from 2.53 μm to 1.08 μm), optimized the distribution of the γ′ strengthening phase, and enhanced both the room-temperature strength and ductility, achieving a tensile strength of 798.36 MPa and an elongation of 1.49%. During isothermal holding at 600 °C, the B‑containing alloy maintains a hardness of 188.3 HV with a fluctuation of less than 10 HV, demonstrating excellent thermal stability. In terms of high-temperature tribological performance, the boron-microalloyed alloy exhibits a friction coefficient of 0.43 under low-speed conditions and 0.35 under high-speed conditions at 600 °C. This significantly improves the service behavior of the alloy under high-temperature friction conditions.

Cl-doped SnO2 (CTO) films were prepared utilizing ultrasonic spray pyrolysis technology, where SnCl2 was the single source for both tin and chlorine. The effect of substrate temperature was systematically studied on the crystalline state, surface morphology, thickness, optical and electrical properties, and thermal stability. Phase analysis indicated that the critical substrate temperature for crystallizing the CTO film is about 450 degrees C. Furthermore, the preferred orientation of the films evolved from (200) orientation to a dual orientation of (211) and (301) with increasing substrate temperature. All the film deposited at higher temperature (>= 500 degrees C) presented pyramidal surface morphology with clear grain boundary. we deduced that the pyramidal morphology is primarily attributable to the crystal structure of SnO2 (containing Sn-O-6 octahedra) and the anisotropic growth behavior (i.e., preferred orientation), rather than to any specific crystallographic orientation. Moreover, the Cl concentration, denoted by the ratio of [Cl-]/(2 & times; [Sn4+], decreased markedly from 9.53% to 0.14% with increasing substrate temperature. From the correlation between the bandgap and the Cl concentration, we deduced the solubility limit for Cl doping in SnO2 to be about 0.80 at.% (i.e., [Cl-]/(2 & times; [Sn4+]) = 0.80%). The film deposited at 500 degrees C exhibited the lowest resistivity (1.11 & times; 10(-3) Omega & centerdot;cm) and outstanding electrical stability, showing no degradation in electrical conductivity after one week of aging at 150 degrees C and even a slight improvement. All in all, our study reveals that the CTO film has great promise for optoelectronic applications and deserves more attention.

Ultra-high strength maraging stainless steels possess many important applications such as in aircraft landing gears owing to their excellent strength and good process ability. However, traditional ultra-high strength maraging stainless steels are facing the challenge of balancing strength and ductility while pursuing ultra-high strength. This is mainly due to the semi-coherent or non-coherent relationship between the precipitated nanoparticles and the body-centered cubic (BCC) martensitic matrix. In this work, a novel ultra-high strength maraging stainless steel (Fe-7.95Cr-13.47Ni-3.10Al-1.83Mo-0.03C-0.23Nb, weight percent, %) is designed using a cluster formula approach. Alloy ingots are prepared by vacuum induction melting under an argon atmosphere, followed by hot rolling at 950℃ and multiple passes of cold rolling. Finally, the alloy is aged at 500℃ for 288 h. Microstructural characterizations of the alloy in different aging states are performed using electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). As a result, the martensitic structure of the alloy is fragmented and elongated, with high-density dislocations (~ 1.8 × 10–3 nm–2) and a large number of coherent B2-NiAl nanoparticles (< 5 nm) observed in the BCC martensitic matrix after cold rolling and aging. In terms of mechanical properties, the alloy exhibits significant age-hardening, with a peak-aged hardness of 651 HV after ageing treatment. It also demonstrates an extraordinarily high yield strength (σYS = 2.3 GPa) and a decent elongation (El = 3.6%), indicating a well-balanced strength-ductility property. Finally, the origins of the ultra-high strength in the novel alloy are discussed in depth, showing that the ultra-high strength of this stainless steel comes from the strengthening effect of different microstructures. This study provides valuable guidance for designing high-performance ultra-high strength maraging stainless steels.