To address the poor room-temperature plasticity of Mg alloys, this study proposes a method called twist strain-induced twin orientation regulation (TITOR). Firstly, compressive strain is applied along the extrusion direction (ED) to generate preset 10–12 tensile twins, and then torsional deformation is introduced by screw twist extrusion (STE) to regulate the initial twin orientation. The results show that the TITOR process is dominated by continuous dynamic recrystallization (CDRX). Among them, STE will weaken the basal texture effectively. Under the continuous torsional stress, the c-axis of grains will deviate 30° in the transverse direction (TD), thereby refining the grains and promoting the movement of the basal slip obviously. By introducing controllable torsional deformation to conduct secondary regulation on the twin orientation at a large angle, the problem of poor low-temperature plasticity of Mg alloys is improved. As the increase of volume of pre-twinned, the mechanical properties and orientation regulation of Mg alloys have been improved significantly. Especially, the ultimate tensile strength (UTS) of 3

This study investigates how aging-induced carbide precipitation affects the intergranular corrosion (IGC) susceptibility of low-carbon austenitic stainless-steel C-HRA-5. The solution-treated sample contained sparse primary Nb-rich MX precipitates in an austenitic matrix, whereas aging promoted grain-boundary carbide precipitation and progressive coarsening. TEM-EDS line scans revealed increasing Cr enrichment at grain-boundary carbides together with a more pronounced local C-enriched/Cr-depleted region as the aging temperature increased. The solution-treated and 650 degrees C-aged samples showed low DOS values and limited intergranular attack, while aging at 750 and 850 degrees C markedly increased DOS and produced deeper grain-boundary grooves after DL-EPR testing. These results indicate that IGC susceptibility is controlled by the continuity/coarsening of grain-boundary carbides and the associated local chemistry gradient. This work provides a microstructure-based interpretation of why Nb-bearing C-HRA-5 can still become sensitized during high-temperature exposure.

Ageing treatment is a simple yet effective method for enhancing the mechanical performance of magnesium (Mg) alloys. This study investigates the precipitation behaviour, precipitation-free zone (PFZ) evolution, and strengthening mechanisms of Mg–7Gd–2Nd–0.5Zr (wt.

To examine the effects of different loading directions on mechanical behaviors and dynamic recrystallization of AZ31 magnesium alloy. Uniaxial hot compression experiments were conducted on the original AZ31Mg alloy at 0°, 15°, 30°, 45°, 60°, 75°, and 90° directions on the ND–RD plane. The results show that the sample compressed in the RD direction has a higher degree of dynamic recrystallization, and tensile twins promote the dynamic recrystallization behavior during the hot compression process. There are very few residual twins in the deformed samples. The compression behavior of samples with different orientations on the ND–RD plane shows anisotropy. The yield strength of the samples decreases first and then increases with the increase of the angle. The mechanical behavior of samples with different orientations shows anisotropy. The dynamic recrystallization mechanism of the samples is not affected by the spatial orientation. The dynamic recrystallization mechanism of the 0°, 45°, and 90° samples is all continuous dynamic recrystallization.

Laser powder bed fusion (LPBF) enables the fabrication of complex, high-performance Inconel 718 (IN718) components with unique non-equilibrium microstructures that are characterized by cellular substructures, elemental segregation, and Laves phase formation. Applications of LPBF IN718 with high strength in hydrogen-rich environments are limited by their low hydrogen embrittlement (HE) resistance. Keeping this in view, we examine the role of solutionizing temperature on the strength and HE resistance of solutionized and double aged (SA) LPBF IN718 with the aid of slow strain rate tensile (SSRT) tests that are conducted in air as well as in situ hydrogen charging conditions. Results reveal that solutionizing at a relatively low-temperature of 980 °C (LSA) enhances strength while maintaining HE resistance comparable to the as-built alloy, owing to retained dislocation cellular networks decorated with the Laves phases and nanoscale γ'/γ'' precipitates that promote uniform hydrogen distribution and suppress strain localization. In contrast, high-temperature solutionizing at 1150 °C (HSA) results in the dissolution of cellular structures and recrystallization and grain growth that leads to a microstructure with coarse equiaxed grains. The latter facilitate rapid hydrogen diffusion along their boundaries, which results in severe intergranular cracking. These findings demonstrated that controlled, lower-temperature solutionizing enables a balanced optimization of strength and HE resistance in LPBF-produced precipitation-strengthened superalloys, providing valuable guidance for the post-processing design of materials intended for applications in hydrogen-rich environments.

ABSTRACT Selective conversion of biomass‐derived glycerol into high‐value chemicals is challenged by poor selectivity and mass‐transfer limitations. Here, a BiOI/Au/TiO 2 photoanode is developed, where plasmonic Au mediators facilitate a transition from Type‐II to Z‐scheme charge transfer. This heterojunction preserves strongly oxidative holes on the TiO 2 surface, as confirmed by femtosecond transient absorption spectroscopy and spatially resolved MnO x photodeposition. In situ characterizations and density functional theory (DFT) reveal that this hole‐rich interface strengthens specific primary hydroxyl (pri‐OH) adsorption, lowering the rate‐determining dehydrogenation barrier to ∼0.6 eV. It also promotes rapid glyceraldehyde (GLAD) desorption, suppressing over‐oxidation. In a static H‐cell, the photoanode achieves 87% GLAD selectivity with a glycerol conversion rate of 341.25 mmol·m −2 ·h −1 . To overcome diffusion limitations, computational fluid dynamics (CFD) simulations were employed to design a continuous‐flow reactor for the 100 cm 2 large‐area photoanode. The flow system prevents product accumulation, boosting GLAD selectivity from 48% (H‐cell) to 77% for the large‐area electrode, with enhanced glycerol conversion (60.34%) and stable 120 h operation. This work provides a laboratory scale‐up by integrating nanoscale reprogramming with macroscale reactor engineering.

Transition metal selenides (TMSs) are promising conversion-type anodes with high specific capacity. However, their reconstructed solid electrolyte interphase (SEI) layers formed by ester-based electrolytes are relatively loose and unable to withstand structural expansion. Herein, this work demonstrates an effective interface modification strategy via the built-in electric field from ZnSe/NiSe2/CoSe2@NC (ZNCS@NC) cascade type-II heterostructures and the regulation mechanism of nitrogen-doped carbon matrix confinement. The ZNCS@NC achieves excellent performance (658 mAh g−1 at 0.5 A g−1) and reliable cyclability (427 mAh g−1, 97.4% capacity after 3000 cycles at 5 A g−1), delivering favorable capacities at −15 °C (343 mAh g−1 at 0.5 A g−1). During the continuous sodiation/desodiation processes, the SEI can gradually evolve into a stable structure with continuous compactness, thereby ensuring excellent long-term cycling stability and showing substantial potential for practical applications. The ZNCS@NC//NVP coin-type full cell exhibits a promising capacity (323 mAh g−1 at 0.5 A g−1), and the pouch-type full cell maintains excellent mechanical damage resistance. This work paves the way for regulation of the electrode-electrolyte interfacial chemistry through rational electrode structure design towards high-performance SIB anodes for future commercial applications.

Herein, low-Gd-content Mg-Gd-Zr system alloys with novel strength and adequate ductility were prepared by Nd and Y elements alloying combined with hot extrusion. The effects of Nd and Y elements on the microstructure, texture and mechanical properties of as-extruded Mg-6Gd-0.5Zr (VK61), Mg-4Gd-2Nd-0.5Zr (VEK421) and Mg-4Gd-2Y-0.5Zr (VWK421) alloys were investigated. The results showed that the addition of Nd not only refines and homogenizes the alloy structure but also promotes the dynamic precipitation of the secondary-phase particles during the extrusion process; while the addition of Y significantly inhibits the recrystallization behavior of the alloy during extrusion, forming a typical bimodal structure. After extrusion, the VK61 and VEK421 alloys consisted of fine dynamic recrystallization (DRX) grains while the VWK421 alloy consisted of fine DRX grains and coarse deformed grains. The as-extruded VEK421 alloy demonstrated optimal plasticity, characterized by a UTS of 245.4MPa and an EL of 33.6%. The as-extruded VWK421 alloy had the highest volume fraction of the second phase, the lowest recrystallization volume fraction, and the highest texture intensity. It also exhibited optimal tensile strength; ultimate tensile strength (UTS) and elongation (EL) were 261.6MPa and 18.2%, respectively, 66.7% and 106.8% higher than the as-solutionized alloy. The alloy-strengthening mechanisms mainly include fine grain strengthening and dislocation strengthening. Moreover, the presence of DRXed grains with a weak texture plays a significant role in improving the plasticity of the alloy.

In Fe-Cr alloys, lanthanum (La) has garnered a significant interest for enhancing Fe-Cr alloys oxidation resistance, yet consensus on its underlying mechanisms remains elusive despite multiple proposed explanations. In this paper, the influence of La on the high-temperature oxidation behavior of Fe-Cr alloys was investigated via long-term exposures in air at 800 for 500 h. The effect of La addition on microstructural evolution, oxidation kinetics, and oxide scale formation was evaluated through coupling an experimental analysis with first-principles calculations. La induces a "fast-nucleation, slow-thickening, strong-adhesion" evolution paradigm, yielding a smaller kp and superior adhesion. Specifically, the enhanced oxidation resistance is attributed to multiscale mechanisms: La segregation at grain boundaries (GBs) of Cr2O3 retards ionic diffusions, La2O3 act as nucleation templates to promote Cr2O3 formation. Moreover, a high density of Fe2(Nb, W) Laves phase precipitates promote the selective oxidation of Cr and inhibit inward oxidation by blocking GBs diffusion paths. First-principles calculations further demonstrate that La2O3 promotes Cr surface segregation and enhances Cr-O bonding stability. This study reveals the synergistic thermodynamic and kinetic roles of La2O3 formation and Laves phase precipitation in constructing adherent, protective oxide scales and provides a guidance for rare-earth microalloying design in oxidation-resistant alloys.

Understanding the coupling between detwinning and slip activity is essential for improving the ductility of magnesium (Mg) alloys, where plastic deformation is governed by basal slip and twinning. Here, we investigate orientation-dependent slip transitions during detwinning in pre-twinned Mg single crystals. Results show that detwinning efficiency strongly depends on loading orientation, being most pronounced at [777 0 829] direction, while it is suppressed at [952 0 586] direction due to a reduced strain-energy gradient. During detwinning, slip in the parent crystal evolves from prismatic slip to pyramidal and pyramidal slip. This transition governs dislocation behavior and lattice distortion: prismatic slip enables long-range glide and tangling, pyramidal slip involves climb-assisted transfer, and pyramidal slip produces highly localized dislocation pile-ups and severe lattice distortion. These findings clarify the mechanistic coupling between detwinning and slip-mode transition, providing guidance for optimizing deformation pathways in Mg alloys.

Mechanical twinning can facilitate the nucleation and growth of new grains during plastic deformation, referred to as twin-induced dynamic recrystallization (TDRX). This process is particularly relevant in hexagonal close-packed (HCP) metals such as magnesium (Mg) and titanium (Ti), where twinning is an important deformation mode. In this work, we studied the TDRX behavior in Mg alloy through pre-introducing twins into a single crystal at room temperature and then compressing the twinned crystals at 643 K under various directions. Electron backscatter diffraction (EBSD) analysis was conducted to investigate the factors influencing TDRX behavior. Four key factors were identified: grain rotation induced by dislocation slips, grain growth driven by twin boundary motion, the orientation effects of thermal compression, and the influence of stacking faults (SFs). The results indicate that grain rotation leads to the formation of low-angle grain boundaries and modifies twin boundary remnants, thereby affecting the misorientation angles during TDRX. The growth of dynamically recrystallized grains is primarily driven by dislocation slip and grain boundary sliding, which reorient boundaries toward higher-index directions. This study provides critical insights into TDRX nucleation mechanisms and offers strategies for enhancing the mechanical properties of Mg alloys through controlling recrystallization processes.

Magnesium-based alloys display poor strength–corrosion resistance synergy in physiological environments, which hinders their widespread use as biomedical materials. To address this challenge, a Mg-0.4Ca alloy with a lamellar grain structure was fabricated via hard-plate rolling. Then, the effects of the lamellar grains on its mechanical characteristics, corrosion and biocompatibility were considered. This structure led to excellent synergy between ductility and strength, with an elongation of 24.8% and a yield strength of 204.4 MPa. In simulated body fluid, a corrosion product dual-layer film comprising an outer Ca(OH)2/Ca3(PO4)2 layer and an inner MgO/Mg(OH)2 layer was formed. After 288 h of immersion in SBF, the alloy maintained a low corrosion rate of 0.03 mm·y−1, indicating good long-term corrosion resistance. The dense and uniform structure of this layer was promoted by the lamellar grain structure, leading to considerably enhanced corrosion resistance and more uniform degradation behavior. In addition, the alloy exhibited a high antibacterial rate of 94.8 ± 1.5% against Staphylococcus aureus after 6 h of contact. This lamellar design offers a practical pathway to synergistically enhancing the corrosion resistance, strength and biological performance of magnesium alloys.

To overcome the limitations of traditional single-crystal X-ray diffraction (SCXRD) for microcrystalline materials and the peak-overlapping issue of powder X-ray diffraction (PXRD), this study employed cryogenic continuous rotation electron diffraction (cryo-cRED) with a low-dose strategy to determine the crystal structure of CL30, a novel silicogermanate framework. It is confirmed that CL30 crystallizes in the C2/m space group and has layered topology composed of discontinuous zigzag chains connected by double four-membered ring (d4r) units, with fluoride anions (F-) occluded in the d4r units. In CL30, charge balance involves organic structure-directing agent (OSDA) cations, occluded F-, and terminal oxygen sites whose protonation state cannot be established from the present three dimensional (3D) ED data. F- encapsulated in the d4r units contributes to charge compensation as the counter-anion to OSDA cations, rather than only balancing the framework charge. Although the refinement indices (R1 = 0.29, wR2 = 0.71) exceeded typical small-molecule crystallography standards, the structural model remained highly reliable, as supported by geometric restraints and validation. In electron diffraction, elevated R1 values are commonly attributed to the intrinsic factors of the technique, such as dynamic scattering, detector noise from scintillator-based detectors, and TEM stage instability (large spheres of confusion). This study introduces a new structural prototype to the silicogermanate family and establishes a feasible workflow for determining the structures of radiation-sensitive microcrystalline porous materials.

In this work, an efficient and innovative texture weakening and grain refinement method, shear strain induced twin orientation regulation (SITOR), was used to improve the ductility of AZ31 at relatively low temperatures below 200 degrees C and the corresponding ductility increasing mechanism was explored. In this way, the grains of the SITORed sample were fine and uniform, the strong basal texture was weakened significantly, and a new SITORed texture was formed about 43 degrees away from the parent basal plane. The results showed that the ductility of SITORed AZ31 was significantly improved at relatively low temperatures compared with initial AZ31 alloy. The basal slip dominated the deformation at room temperature which made the fracture elongation increasing from 15.3% to 32.6%. At 100 degrees C and 150 degrees C, the basal slip was more active than prismatic slip and pyramidal slip at the initial stage of plastic deformation, and the activity of prismatic slip increased and gradually dominated the deformation with the increase of strain. The fracture elongation increased nearly by 30% at 100 degrees C. At 150 degrees C, the fracture elongation of SITORed sample was as high as 63.9%. The fracture elongation increased to 81.7% at 200 degrees C, which was nearly 35% higher than the original sample. This was due to the occurrence of continuous dynamic recrystallization behavior and multiple slip modes co-actuation.

A novel precipitate-free Mg-0.1Sn anode with a homogeneous equal-axis grain structure was developed and rolled successfully at 573 K. Electrochemical test results indicate that the Mg-0.1Sn alloy exhibits enhanced anode dissolution kinetics. A Mg-air battery prepared using this anode exhibits a cell voltage of 1.626 V at 0.5 mA/cm2, reasonable anodic efficiency of 58.17%, and good specific energy of 1730.96 mWh/g at 10 mA/cm2. This performance is attributed to the effective reactive anode surface, the suppressed chunk effect, and weak self-corrosion owing to the homogeneous basal texture.

In this work, AZ31B extruded sheets with mixed-grain microstructures were prepared through extrusion. Samples of mixed-grain microstructure with different morphologies were selected from the AZ31B extruded sheets (referred to as M1 and M2 samples, respectively). The creep tests were performed on these samples at the temperature range of 150–200 °C, and the stress level range of 50–100 MPa. The creep properties and fracture behavior of AZ31 extruded sheets with mixed-grain microstructures were studied. Results showed that the creep properties of the M2 sample always outperformed that of the M1 sample and M1 and M2 samples’ creep was dominated by dislocation movement. The creep rate of M2 samples (1.5 × 10-7 ± 1.1 × 10-10 s-1) is an order of magnitude lower than that of M1 samples (4.8 × 10-6 ± 8.1 × 10-10 s-1) at 200°C under 50 MPa The high activity of basal slip and softening mechanism in the M1 sample significantly accelerated creep, resulting in a relatively high creep rate. Moreover, the stress concentration within the M1 sample caused by deformation incompatibility, increased the initiation and propagation of voids, ultimately leading to fracture and poorer creep performance. However, the numerous <10 µm fine grains surrounding deformed coarse grains in the M2 sample facilitated better coordination of deformation through dislocation slip, effectively slowing down the initiation of voids during the creep process. Meanwhile, the strain was uniformly distributed within each grain, mitigating stress concentration, inhibiting voids propagation, and contributing to the superior creep resistance of the M2 sample.

To enhance the ductility of Mg-2Zn-1Mn (ZM21) magnesium alloy, this study introduced high-density crossed twins via bidirectional pre-twinning. This process fragmented the microstructure and refined the grains. Subsequently, controlled shear deformation was applied to optimize the twin orientation further, specifically targeting orientations that deviated by 86.3 degrees from the basal plane. The results demonstrate that the sample subjected to 4 passes of bidirectional pre-twinning achieved an ultimate tensile strength (UTS) of 388.1 MPa and a fracture strain (FS) of 38.9 %. This represents significant increases of 53.5 % in strength and 276 % in ductility compared to the as-received sample. The texture was markedly weakened, achieving an ideal shear texture rotated by approximately 50 degrees, which optimized the twin orientation. Combined analysis with the visco-plastic self-consistent (VPSC) model revealed a substantial activation of prismatic slip during tensile deformation in the pre-twinned sample, establishing it as the dominant slip mechanism alongside basal slip. The enhancement in mechanical properties is attributed to the orientation dispersion induced by intersecting twins, the orientation regulation facilitated by shear deformation, and the activation of non-basal slip systems. This study provides a novel approach to developing high-performance magnesium alloys.

Transition behavior of different deformation modes can effectively relieve the local strain concentration through dynamic softening in terms of dynamic recrystallization (DRX). To reveal the response of DRX behavior to the deformation mode, the activation of slip systems and the corresponding DRX modes in an as-extruded Mg-3Bi binary alloy was studied during compression and tension at strain rate of 0.1 s(-1) and a temperature of 200 degrees C. The findings reveal that difference in strain hardening rates in across loading conditions are primarily influenced by the discontinuous yielding stage. During compression, deformation is primarily governed by pyramidal slip and pyramidal slip modes, with together account for more 60 % of the total silp activity. Transition behavior of pyramidal slip to pyramidal slip components promotes continuous dynamic recrystallization (CDRX). Under tensile, prismatic slip is easily activated and dominates the occurrence of DDRX. Additionally, DDRX is more efficient at aleviating stress concentrations compared to CDRX.