Magnesium hydride (MgH2) is regarded as a highly promising hydrogen carrier for hydrogen‐energy infrastructure; however, the intrinsically strong Mg-H bonding severely limits its hydrogen release and uptake under mild operating temperatures. In this work, amorphous Ni0.9Fe0.1-Cr2O3 nanoparticles were synthesized by a one-step co-reduction and integrated with MgH2 by ball milling to accelerate reversible solid-state hydrogen storage. Cr2O3 suppresses long-range ordering of NiFe, yielding nano amorphous catalysts well anchored on MgH2. DFT reveals that Cr2O3 disrupts Ni–Fe exchange and induces a Ni magnetic-moment gradient, which guides H migration and, together with band-overlap-enabled charge transfer, which collectively promote H diffusion and Mg-H bond cleavage. Therefore, temperature-programmed desorption shows the composite starts releasing H2 at 206 °C (about 130 °C lower than pristine MgH2), and delivers 3.56 wt% within 60 min at 235 °C. Overall, these findings establish magnetic-gradient-field regulation as a viable catalyst-design principle for high-performance MgH2-based solid-state hydrogen storage.

The advancement of low-loading Pt catalysts for PEMFCs faces challenges such as Pt nanoparticle aggregation, limited electron transfer efficiency, and inadequate stability. To address these challenges, further optimization of the distribution and electron transfer efficiency of Pt nanoparticles can be achieved by incorporating RE, particularly Ce, which enhances the performance and applicability of the ORR catalyst. The uniform distribution of Pt nanoparticles on CeO2 coupled with surface oxygen vacancy enrichment demonstrates that undercoordinated Ce3+ species anchor Pt precursors via oxygen vacancy (OVs), effectively suppressing nanoparticle aggregation and enhancing catalytic stability. This architecture reduces Pt aggregation and improves electron transfer efficiency. The Pt/CeO2@C catalyst exhibits outstanding electrocatalytic performance, attaining an E1/2 of 0.935 V and an electrochemically active surface area (ECSA) of 101.35 m2/g, representing a 25% enhancement over traditional Pt/C catalysts. Density functional theory (DFT) analysis indicates that d-orbital hybridization between CeO2 and Pt reduces the d-band center of Pt, and the introduction of oxygen vacancies enhances oxygen adsorption, offering more active sites for ORR. This breakthrough offers new opportunities for high-performance, cost-efficient fuel cell catalysts, establishing a robust foundation for future large-scale applications in fuel cell technology.

In flotation, metal ions can activate mineral surfaces, thereby enhancing the collector's ability to recover target minerals. This not only improves flotation efficiency but also reduces reagent consumption and costs. In this study, zinc ions (Zn2+) were employed as an activator and sodium oleate (NaOL) as a collector to achieve efficient flotation separation of diaspore and kaolinite. Single-mineral flotation tests showed that, at pH 9.0 and the NaOL concentration of 2 & times; 10-4 mol/L, the recovery of diaspore reached 96.82%. With the addition of Zn2+ ions (1 & times; 10-4 mol/L), the dosage of NaOL could be halved while still achieving a diaspore recovery of 96.87%, and the recovery of kaolinite remained as low as 2.31%. Artificial mixed minerals flotation experiments demonstrated that under optimal conditions, the reagent system containing Zn2+ ions and NaOL can enrich the aluminum-to-silicon (A/S) ratio of the raw ore from 3.95 to 9.49, with a recovery rate as high as 81.76%. This recovery rate is 48.79% higher than that achieved without the addition of Zn2+ ions during flotation. Contact angle measurements and zeta potential analysis confirmed that Zn2+ ions activate diaspore, thereby enhancing the adsorption of NaOL on its surface. Flotation solution chemistry calculations confirmed that the active collector component of NaOL is the oleate ion ((RCOO)22-), and the activating species of Zn2+ ions is zinc hydroxide precipitate (Zn(OH)2(s)), which forms directly on the surface of diaspore. FTIR and XPS analyses revealed that NaOL chemisorbs on the Zn2+-activated diaspore surface. AFM observations further indicated the occurrence of multilayer adsorption of NaOL on the activated diaspore. Density functional theory calculations indicate that the adsorption strength of Zn(OH)2 on the diaspore surface is greater than that on the kaolinite surface. Thus, the adsorption of NaOL on activated diaspore involves both chemical and physical adsorption mechanisms. This study provides a strategy and reference for using activators to enhance the desilication of high-silica bauxite via flotation.

The pull-out behavior of steel fibers embedded in cementitious matrices significantly governs the post-cracking performance of steel fiber-reinforced concrete (SFRC). while conventional tests provide global force-displacement responses, direct visualization of interfacial stress evolution has remained unexplored. This study employed photoelastic analysis to visualize and interpret real-time interfacial stress distribution during the static pull-out of straight and hooked-end steel fibers at inclination angles of 0 degrees, 30 degrees, 45 degrees, and 60 degrees. Transparent epoxy resin specimens were cast to observe stress fields under polarized light, allowing a detailed assessment of stress-transfer mechanisms. Complementary mechanical pull-out tests on cement paste and concrete specimens further examined the influence of matrix type and fiber geometry. Photoelastic observations revealed progressive redistribution of interfacial stresses, with pronounced stress concentrations near the fiber exit zone as inclination increased. Hooked-end fibers exhibited superior mechanical anchorage and delayed debonding compared with straight fibers, attributable to hook engagement and snubbing-induced confinement. An analytical model confirmed the stress evolution, indicating that the affected stress zone extended to approximately 12.6 times the fiber diameter. Finite element analysis (FEA) effectively simulated the evolution of interfacial stress, aligning with the observed fringe patterns. This combined experimental-numerical approach provides valuable insights into fiber-matrix interaction mechanisms, offering a robust foundation for refining analytical models and optimizing fiber design in SFRC.

Metal-diamond composites offer outstanding mechanical and thermal properties, but are difficult to fabricate in complex shapes due to the hardness and brittleness of diamond particles. Electron beam powder bed fusion (PBF-EB) enables fabrication of metal-diamond composite parts, but the processing parameters should be carefully controlled to avoid the spattering of diamond and residual porosities. The energy density (E-D) is a common parameter for PBF, but there are still large differences in metallurgical quality of PBF-fabricated samples under the same E-D value. In this work, NiCu-diamond composites were fabricated with same E-D value of 144 J & centerdot;m(-1). A NiCu-diamond composite of high densities (> 97%) and low degrees of spattering of diamond particles was successfully manufactured, when electron beam current is lower than 2.4 mA, and scanning rate is below 1 m & centerdot;s(-1). The transverse rupture strength (TRS) of the diamond composite was as high as 670.2 MPa, and the abrasive ratio was 192.3, both greatly increased in comparison with 556.6 MPa and 179.9, respectively. In order to better understand the relationship between the processing parameters and the printing quality of composite parts, a dynamic parameter, the energy change rate (E-C), as a complementary parameter to the energy density (E-D), was introduced for the first time. It was found that, with the same E-D value, a low E-C value is beneficial for printing the NiCu-diamond composite with high metallurgical quality. The newly proposed E-C parameter also demonstrates similar regularity for optimizing the microstructure and properties of PBF-manufactured various materials (including Ti, Fe and Al alloys). Finally, for the first time, complex-shaped drilling parts were produced by PBF-EB process with the optimized E-C parameter, and showed much better wear resistance compared with that of commercial steel drilling parts.

Zr doping is introduced into La-Y-Ni-based alloys to systematically investigate its effects on microstructural evolution and solid-state hydrogen storage properties. Zr doping barely introduces new phases, but remarkably regulates the relative fraction of phases. Notably, preferential tendency of Zr in the [A2B4] subunits decreases the volume of the [A2B4] subunits more substantially than that of the [AB5] subunits, thereby effectively narrowing the volume mismatch between them. Consequently, with increasing Zr content, a single and elevated plateau pressure is achieved. An optimal amount of Zr addition significantly enhances both the reaction kinetics and cyclic stability, as evidenced by the reduced activation energy and the improved retention of particle size and lattice parameters after cycling. Although Zr doping leads to a slight reduction in hydrogen storage capacity, the remarkable improvements in plateau characteristics and cycling lifespan make these Zr-modified La-Y-Ni-based alloys highly promising candidates for future applications through subsequent optimization strategies.

{112¯2} twinning is widely activated in α-titanium (α-Ti) to accommodate the strain along the c-axis. The short, three-layer height bands are observed along {112¯2} twin boundary, but the formation mechanism and atomic structure of these bands are in debate. In this work, we characterized atomic structure of these bands by using high-angle annular dark-field scanning transmission electron microscopy. Combining with topological analysis and first-principles density functional theory calculations, our conclusion is that these bands have a distorted ω-phase structure. The formation of the distorted ω-structure can be treated as the dissociations of a three-layer twinning disconnection (b3, 3h{112¯2}), where a leading partial disconnection (1/2b3, 3h{112¯2}) and a trialing partial disconnection (1/2b3, 3h{112¯2}) are bounded by a distorted ω-structure. Correspondingly, we proposed possible mechanisms for twin thickening via partial disconnections. These findings enhance the fundamental understanding of twinning behavior in hexagonal metals.

{1122} twinning is widely activated in alpha-titanium (alpha-Ti) to accommodate the strain along the c-axis. The short, three-layer height bands are observed along {1122} twin boundary, but the formation mechanism and atomic structure of these bands are in debate. In this work, we characterized atomic structure of these bands by using high-angle annular dark-field scanning transmission electron microscopy. Combining with topological analysis and first-principles density functional theory calculations, our conclusion is that these bands have a distorted w-phase structure. The formation of the distorted w-structure can be treated as the dissociations of a three-layer twinning disconnection (b3, 3h{1122}), where a leading partial disconnection (1/2b3, 3h{1122}) and a trialing partial disconnection (1/2b3, 3h{1122}) are bounded by a distorted w-structure. Correspondingly, we proposed possible mechanisms for twin thickening via partial disconnections. These findings enhance the fundamental understanding of twinning behavior in hexagonal metals.

Controlling planar fault shearing modes is key for improving the high-temperature creep performance of gamma '-strengthened superalloys. This work investigates the effect of Ti concentration on planar fault shearing modes during creep in L12-strengthened CoNi-based superalloys. Interrupted compressive creep tests were conducted at 1223 K under low applied stress and at 1123 K under high applied stress. We found, for the first time, that high Ti additions shift the dominant gamma ' shearing mode from antiphase boundaries (APBs) in Ti-free and low-Ti alloys to superlattice extrinsic stacking faults (SESFs). Systematic ab initio calculations show that in high-Ti alloys, the elevated APB energy renders APB-shearing mode unfavorable. Nevertheless, the SESF energy decreases relative to that in low-Ti compositions, and an increased ratio of complex intrinsic stacking fault (CISF) to SESF energy promotes the transformation of high-energy CISFs into lowerenergy SESFs. Chemical analysis using scanning transmission electron microscopy combined with energy-dispersive X-ray spectroscopy further reveals that, SESFs in high-Ti alloys are enriched in Ti, Mo and W, yet no grid-like ordering is observed. Combined with the ab initio calculations, the results suggest that Mo and W additions facilitate the transformation from the L12 structure to the lower-energy D024 structure. This indicates that Mo and W segregation along SESFs is energetically favourable. Furthermore, the successive SESF thickening facilitates microtwinning in the absence of D024 ordering along SESFs, as an additional major carrier for creep strain. These new findings clarify the role of Ti in controlling planar fault shearing modes, providing new insights for optimizing the creep performance of next-generation CoNi-based superalloys.

Polycrystalline diamond compacts (PDCs) are extensively utilized in hard-to-work fields, such as deep oil and gas drilling. In order to study the effect of diamond morphology on the structural integrity of polycrystalline diamond (PCD) layer, PDC samples with different particle gradation were fabricated using single-crystal diamond and crushed diamond as raw materials. The microstructure and mechanical properties of PDCs were systematically characterized. The results indicated that using single-crystal and fine crushed diamond powders to prepare bimodal PDC could enhance the structural integrity of the PCD, thereby improving its mechanical properties. During high-pressure high-temperature (HPHT) synthesis, the bimodal PDC exhibited reduced fragmentation and higher diamond skeleton contiguity. The use of single-crystal diamond reduced defects in the diamond phase, such as microcracks. These improvements, together with the reinforcing effects of a higher diamond content and fraction of twin boundary, led to a 6.86 % increase in Knoop hardness and a 294 % improvement in wear ratio, compared to conventional bimodal particle size PDCs with both crushed diamonds. The findings indicate that employing a bimodal particle size distribution comprising single-crystal and fine crushed diamond powders enhances the structural integrity of the PCD layer, leading to superior mechanical properties.

Achieving long-term stable Zn metal anodes with iso-plating/stripping remains a great challenge for practical rechargeable Zn-ion batteries. Herein, we propose a surface engineering strategy utilizing ultrafine Cu4Zn@Zn core-shell powders fabricated via powder metallurgy. The zincophilic Cu4Zn@Zn interlayer functions as a spatially confined reactor, orchestrating uniform Zn deposition at preferential nucleation sites while facilitating rapid Zn2+ transport via selective dissolution of the metallurgical active Zn core, thereby eliminating current localization and achieving highly reversible stripping/plating behavior. Consequently, the modified electrode delivers remarkable performance: a low polarization (15.32 mV at 1 mA cm- 2, 35.30 mV at 10 mA cm- 2), a high Coulombic efficiency (99.81% at 5 mA cm- 2 for 4000 cycles), and a long-term stability over 2370 h under harsh conditions (10 mA cm- 2). When paired with an NH4V4O10 cathode, the full cell maintains 79.83% of its capacity after 1500 cycles at 5 A g-1. This work provides an effective surface-engineering strategy for Zn anodes and opens a new avenue for stabilizing metal electrodes in aqueous battery systems.

High-temperature deformation in superalloys is governed by the cooperative glide-climb motion of dislocations. Superlattice stacking faults (SFs) in the gamma ' phase are predominantly interpreted as nucleating via conservative Shockley partial glide. Here, we demonstrate that non-conservative climb of a/3(111) Frank partials constitutes a kinetically viable pathway for both superlattice intrinsic (SISFs) and extrinsic stacking faults (SESFs) formation in the L12 structure of CoNi-based superalloys during compression at 850 degrees C. High-resolution transmission electron microscopy reveals that Frank partials form at gamma/gamma ' interface can climb into the gamma ' phase, generating SISFs via positive climb and SESFs via negative climb. Importantly, the negative climb-assisted nucleation of SESFs is experimentally confirmed for the first time, and the observed positive climb-assisted SISF configuration differs fundamentally from previously reported mechanisms. We show that these Frank partials originate from the reaction between a leading 30 degrees Shockley partial and a 60 degrees mixed dislocation on conjugate {111} planes, producing energetically stable configurations that promote subsequent climb. Energetic and kinetic analyses demonstrate that solute segregation induced reduction of SF energy provides a dominant contribution to Frank partial climb, enabling sustained climb and consequent SF expansion. Quantitative comparisons further indicate that, at elevated temperatures, solute drag-controlled Shockley glide can achieve mobilities comparable to vacancy diffusion-controlled Frank climb. These findings establish climb-assisted SF formation as an important deformation mechanism in gamma ' phase, and that both SISF and SESF expansion can proceed through Frank partial climb, providing new insights into dislocation-controlled high-temperature deformation in CoNi-based superalloys.

The separation of quartz and albite, critically important for the industrial minerals sector, remains a formidable challenge due to their similar physicochemical properties. The industry-standard hydrofluoric acid method poses severe environmental and safety risks, while existing fluorine-free alternatives often require highly corrosive or alkaline conditions and suffer from issues like unstable froth. This study introduces a novel, sustainable flotation strategy using a synergistically combined collector system: a newly synthesized oligomeric surfactant, THQ-8, and sodium oleate (NaOL). The tailored hyperbranched structure of THQ-8 was designed to provide powerful collection while mitigating the persistent froth stability of conventional cationic collectors. Micro-flotation tests demonstrated that this mixed system achieved exceptional selectivity under a mild alkaline condition (pH 9.0) at a low total concentration (10 mg/L, NaOL/THQ-8 mass ratio = 1:2), recovering 95.04% of quartz while effectively depressing albite (recovery = 1.77%). In mixed mineral flotation with a 1:1 mass ratio of quartz to albite, the concentrate yielded 83.44% quartz recovery with an albite recovery of 13.90%, confirming the effectiveness under more realistic conditions. This performance successfully decouples efficient separation from extreme pH environments. A multi-faceted analytical approach, including contact angle measurements, FTIR, XPS, and AFM, revealed the adsorption mechanism. A robust "liquid film" with hydrophobic aggregates formed on quartz via synergistic chemisorption and hydrophobic co-assembly, whereas a competitive adsorption on albite led to a disordered, non-hydrophobic layer. This work establishes a new paradigm for quartz-albite separation, highlighting the immense potential of oligomeric surfactant design in developing efficient and environmentally benign mineral processing reagents.

Predicting how mineral crystals split influences grinding, liberation and downstream flotation, yet routine density-functional-theory evaluation of many candidate surfaces remains prohibitively expensive. Building on the surface broken-bond-density theory of Gao et al.(2012) and the crystal-plane fracture-energy density Sc formulation of He et al.(2022), we present DBv2.0, an open-source Python package that reads standard crystallographic files, builds a periodic bond graph, weights each bond by its Brown–Altermatt bond valence or a length-adjusted bond energy, and ranks candidate Miller planes by Sc=∑niEi2A. Zircon (ZrSiO4) is used as a representative case: DBv2.0 identifies 48 bonds in the conventional cell and ranks the XRD-derived, deduplicated families in the order {100} < {112} < {312} < {332}, with {100} as the easiest-cleaving plane family. The workflow provides a transparent, reproducible bridge from crystallographic input files to bond-energy-based cleavage tendency.

The microstructure, room-temperature and high temperature compressive properties, as well as oxidation behavior of Nb-16Cr-16Ti-xAl-16Zr (2, 5, 16 at. %) alloys were systematically evaluated in this study. The results show that all alloys exhibit a dual-phase microstructure consisting of a BCC solid-solution matrix and a Laves phase. Decreasing the Al fraction promotes a C14-to-C15 Laves phase transformation and decreases its volume fraction, which together enhance high-temperature strength and deformability. Oxidation tests show that all the investigated alloys exhibit superior oxidation resistance compared with Nb521, with the 16Al containing alloy demonstrating the best performance due to the formation of a protective AlNbO4-containing oxide scale. These findings can provide valuable insights for the design of advanced Nb-based alloys for high-temperature applications.

Weak magnetic collectability limits the wet separation of hematite-bearing resources under mild processing conditions. In this study, glucose-assisted wet treatment was evaluated as a mild approach to regulate the interfacial chemistry and magnetic collection behavior of an impure hematite-bearing feed. The effects of pH, glucose concentration, temperature, and solid-to-liquid ratio on the dry-mass yield of magnetically collected products were systematically investigated, while XRD, FTIR, SEM-EDS, VSM, and XPS were used to clarify the phase assemblage, surface chemistry, morphology, and magnetic collection behavior of the products. Under a reaction time of 1.5 h and stirring at 450 rpm, the highest magnetic-product yield of similar to 20.0%, was obtained at pH 6.0. The XRD patterns remained dominated by hematite and associated impurity phases, indicating that the treatment preserved the main crystalline phase assemblage. Glucose dosage exhibited a non-monotonic effect: 0.1 mol/L and 0.4 mol/L produced comparable yields, but 0.1 mol/L was preferred because it minimized reagent consumption and reduced the likelihood of excessive surface residue accumulation. Under pH 6.0 and 0.1 mol/L glucose, increasing temperature above 60 degrees C did not improve product yield, and the solid-to-liquid ratio displayed an optimum at 1:5. No clear bulk phase transformation to a new crystalline iron oxide phase was detected by XRD. Instead, the combined evidence suggests that the change in magnetic-product yield is associated with limited surface or near-surface Fe3+-to-Fe2+ conversion, perturbation of the Fe-O coordination environment, Ferich particle aggregation, and selective enrichment during magnetic collection. These results define the operating window for glucose-assisted wet magnetization under mild aqueous conditions and provide a restrained mechanistic basis for the low-temperature magnetic recovery of hematite-bearing resources such as red mud.

Wear-resistant materials underpin modern manufacturing, energy and transportation technologies, yet their high-temperature durability remains limited by inadequate strain accommodation and unstable tribo-oxidized interfaces. Here we report a cemented high-entropy carbide (HEC), (Ti,W,Ta,Nb)C–Ni, that addresses these coupled challenges through an “entropy-enabled amorphous tribo-oxide shielding” strategy. The key is to construct a stable dual-FCC architecture comprising a multicomponent FCC carbide and an FCC-Ni binder, in which pronounced lattice distortion and sluggish diffusion refine the carbide grains, attenuate core–rim heterogeneity and enhance carbide/binder interfacial cohesion. During high-temperature sliding, friction activates a non-equilibrium reaction between the HEC surface and environmental oxygen, producing an in situ high-entropy amorphous oxide film with a thickness of 6–16 nm and a representative composition of Ti18W12Ta6Nb5O59 at.%. Unlike brittle crystalline oxide scales that tend to crack, fragment and delaminate, this nanoscale continuous amorphous film stabilizes the real contact interface, accommodates interfacial shear and suppresses abrasive wear and adhesive transfer. As a result, the optimized HEC–Ni hard material exhibits an exceptionally low wear rate of 5.81 × 10-7 mm3/N·m and a low coefficient of friction of 0.14 at 600 °C. It also combines a low density of 9.20 g/cm3, a high hardness of 1305 HV30 and high fracture toughness of 15.13 MPa·m1/2 at room temperature and 12.23 MPa·m1/2 at 600 °C. This work establishes amorphous tribo-oxide shielding as a design strategy for hard materials that require both bulk damage tolerance and adaptive surface protection under extreme tribological conditions.

In the present work, a eutectic high-entropy alloy (EHEA) consisting of equiaxed C14 Laves and FCC phases was fabricated via hot extrusion of pre-alloyed powders. The compressive behavior of this EHEA was systematically investigated across a wide range of temperatures and strain rates, revealing an exceptional combination of strength and ductility. The multicomponent Laves phase, although intrinsically brittle, exhibits noticeable plasticity under the tested conditions, with cracks initiating in Laves phase and being effectively arrested by the ductile FCC matrix. The FCC phase accommodates strain through dislocation slip, twinning, and dynamic recrystallization (DRX) at elevated temperatures and strain rates, enhancing crack-arresting capability and overall ductility. This work highlights the synergistic role of Laves and FCC phases in achieving balanced strength and ductility, providing a promising design strategy for high-performance structural alloys under extreme service conditions.

Achieving synergy between ultra-high strength and plasticity in nanocrystalline metals remains a grand challenge, as they are typically plagued by intrinsic brittleness arising from catastrophic shear localization. Here, we overcome this limitation by engineering an oxide/nanocrystalline dual-phase (ONDP) architecture within a CoCrFeNiMn high-entropy alloy via rapid current-activated sintering. Guided by atomistic simulations and lattice misfit calculations, a high density of semi-coherent C15-Cr2MnO4 nanoprecipitates was successfully introduced via an ethylene glycol-assisted ball milling and sintering process. The fabricated alloy delivers a compressive yield strength of 4.5 GPa, which is among the highest values reported for nanocrystalline fcc metals/alloys tested by micropillar compression, while maintaining >30% uniform plasticity. Mechanistically, these semi-coherent oxides effectively suppress grain rotation and convert the nanocrystalline matrix into dislocation storage reservoirs, thereby avoiding strain localization and enabling pronounced strain hardening. This study establishes a scalable pathway for stabilizing nanostructures through O-induced dual-phase engineering, offering a blueprint for next-generation high-performance structural materials.

Unlike conventional Elinvar alloys that rely on magnetoelastic effects or phase transitions, NiTi-type multi-principal element B2 intermetallics, such as CoNiTiZr, exhibit the Elinvar effect through intrinsic modulus hardening due to the thermal alleviation of lattice distortion. While both the atomic size mismatch and sublattice frustration contribute to lattice strain, the specific role of sublattice frustration in lattice distortion and elastic behavior across temperatures remained unclear. We show that atomic size mismatch introduces localized strain fields, while electronic structure randomness frustrates symmetry-breaking transformations and delocalizes lattice strain, thus mitigating overall distortion. Further, we proposed a sublattice engineering model that quantitatively predicted the temperature-dependent elastic modulus of both multiple-element B2 intermetallics and body-centered cubic alloys. The model revealed a strong distortion-modulus coupling in the B2 structure due to covalent bonding contributions and accurately illustrated the Elinvar mechanism. This framework offers a physically grounded approach for designing lattice-distortion-induced Elinvar alloys with improved thermoelastic stability.