Journal of Advanced Ceramics•2026•DOI: 10.26599/JAC.2026.9221349
Polymer-derived SiC-based ceramic fibrous membranes are lightweight, thermally stable electromagnetic wave absorbers, but simultaneously achieving strong attenuation and good impedance matching remains difficult due to limited control over phase composition and dielectric behavior. This work prepares multiphase SiC-based fibrous membranes by electrospinning combined with polycarbosilane (PCS)-derived ceramic conversion. Phase evolution, fiber morphology, dielectric response, and electromagnetic wave absorption are regulated by tuning PCS content and pyrolysis temperature. Advanced characterization confirms a heterogeneous β-SiC/SiOxCy/carbon multiphase structure with good flexibility, providing abundant polarization centers, moderate conductive pathways, and multiple reflection sites, thereby balancing impedance matching and dielectric loss. The sample with 1.4 g PCS pyrolyzed at 1400 °C achieves a minimum reflection loss (RLmin) of −27.12 dB at 2.2 mm and a maximum effective absorption bandwidth (EAB) of 8.22 GHz at 2.7 mm, covering 9.78–18 GHz. Radar cross-section simulation verifies electromagnetic scattering suppression of the optimized fibrous ceramic coating. This study provides a strategy for tailoring phase composition and dielectric behavior in polymer-derived SiC-based fibrous membranes for broadband electromagnetic wave absorption.
China Foundry•2026•DOI: 10.1007/s41230-026-5175-5
To address the dimensional accuracy challenges in investment casting of DD6 nickel-based superalloy hollow turbine blades, a multi-parameter collaborative optimization and deformation response prediction method based on response surface methodology was proposed. Using a Box-Behnken design, with pouring temperature, shell temperature, and withdrawal rate as key variables, deformation response data were obtained through numerical simulation, and a second-order model incorporating linear, interaction, and quadratic terms was established to characterize the nonlinear coupling effects of process parameters on dimensional deformation. The results indicate that withdrawal rate is the dominant factor influencing deformation, while shell temperature exhibits a pronounced “U”-shaped nonlinear trend. Significant interactions between process parameters are also observed. The constructed model demonstrates high predictive accuracy, with R2 of 0.978 and an RMSE of 0.0026 mm, and exhibits strong generalization capability, enabling the identification of optimal parameter combinations even beyond the simulated dataset. Compared with conventional orthogonal design methods, the maximum deformation of the optimized process was reduced from 0.2021 mm to 0.1905 mm, achieving an improvement of approximately 5.74%. This work provides a theoretical foundation and practical strategy for dimensional accuracy control and multi-parameter process optimization in the manufacturing of complex thin-walled castings.
China Foundry•2026•DOI: 10.1007/s41230-026-5182-6
Abstract: In recent years, Al-Ti-Nb-B grain refiners have attracted increasing attention due to their grain refinement performance and anti-Si poisoning ability. This study investigates the influence of the introduction sequence of Ti and Nb during the synthesis of Al-4Ti-1Nb-1B refiners on their refinement performance on CP-Al and a series of Al-Si alloys (Al-3.5Si, Al-7Si, and Al-10.5Si). It is found that Al-4Ti-1Nb-1B prepared by introducing Ti prior to Nb exhibits the best grain refinement and anti-Si poisoning compared to samples where Nb is introduced before Ti or where both are added simultaneously. This Ti-first approach demonstrates superior grain refinement performance across CP-Al, Al-3.5S1, Ai-7Si, and Al-10.5Si alloys, especially at higher Si contents. It refines the grain size of Al-7Si to 150.1±27.5 μm from over 1,500 μm for the unrefined alloy. This superior performance is attributed to the variation in ground-state energy ΔE for the Ti prior to Nb sequence is lower than that of other sequences, thereby facilitating Nb adsorption on the TiB2 surface. TEM observations corroborate these findings, showing that TiB2 prepared by this sequence has the highest average Nb content of 3.80at.%. First-principles calculations reveal that this unique Nb adsorption enhances the TiB2/Al interfacial adhesion energy Wad and suppresses the segregation tendency of Si atoms at the interface, κSi(cSi). The higher the Nb adsorption at the TiB2/Al interface, the stronger the resistance to Si poisoning. These findings underscore the pivotal role of Nb-modified TiB2 in improving grain refinement and offer a novel strategy for advancing grain refiner technologies in Al-Si alloys.
China Foundry (中国铸造 - 英文版)•2026•DOI: 10.1007/s41230-026-4218-2
Enhancing corrosion resistance in cast alloys using straightforward and cost-effective micro-alloying techniques has emerged as a key area of investigation in materials science. The challenge lies in applying this technique to further enhance the already excellent properties of CoCrNi medium-entropy alloys (MEAs) for casting applications. A micro-alloying approach was proposed to improve the corrosion resistance of as-cast CoCrNi MEAs by incorporating cerium (Ce). The corrosion resistance of CoCrNi MEAs firstly increases and then decreases as the Ce content increases in a 3.5wt.% NaCl solution. At a Ce content of 0.02at.%, the passivation current density reaches its minimum value (26.383 μA·cm-2), while the breakdown potential reaches its maximum (0.471 VSCE), imparting exceptional corrosion resistance. The results indicate that the enhanced corrosion resistance is primary due to Ce micro-alloying, which affects inclusions by forming a non-conductive precipitated phase and modifying the passivation film. Ce micro-alloying presents a promising strategy for enhancing the corrosion resistance of as-cast CoCrNi MEAs.
Journal of Central South University•2026•DOI: 10.1007/s11771-026-6266-6
To reduce the subjectivity of conventional instability criteria in deep rock engineering, this study develops an energy-driven criterion grounded in cusp catastrophe theory and embeds it within an improved nonlinear Hoek-Brown (H-B) strength-reduction framework. We derive an explicit algebraic transformation that maps a quartic energy potential to the standard cusp form and introduce the mutation eigenvalue Δ as a physically interpretable measure of proximity to the vanishing of the energy barrier. Building on this, failure staging is diagnosed in practice by the concurrence of a slope mutation in displacement-reduction-factor curves, a threshold jump of total plastic strain-energy increment typically exceeding threefold between adjacent reduction steps, and video-confirmed crack through-connection. Integrating Δ with the nonlinear reduction scheme yields reproducible integral safety factors. Two representative cavern layouts (Model A/B) are validated by scaled physical model tests and companion simulations: global failure occurs at the overload safety factor K=2.33 for Model A and K=2.73 for Model B, with relative deviations from tests (2.4P0 and 2.9P0) of 1.3% and −5.9%, respectively, coinciding with the energy-jump threshold and the multi-evidence diagnosis. Compared with the equivalent Mohr-Coulomb parameter approach, the improved nonlinear scheme produces smaller (more conservative) safety factors by 5.7% and 2.5%, while better matching the observed destabilization process. The framework clarifies the role of Δ as an energy-based instability indicator and offers a practical, verifiable criterion for cavern stability assessment.
Journal of Central South University•2026•DOI: 10.1007/s11771-025-6125-x
This comprehensive study investigates the formation and evolution of intermetallic compounds during the solidification process of magnesium alloys using advanced micro X-ray computed tomography. By analyzing both common industrial Mg-Al-Zn alloys and a novel rare earth-containing Mg-Ni-Gd-Y alloy, we aim to characterize the nucleation, growth, and distribution of Al-Mn and eutectic intermetallics across various stages of solidification. The non-destructive imaging technique employed in this research provides high-resolution, three-dimensional insights into the microstructural development, allowing for a detailed examination of the morphology, spatial arrangement, and interconnectivity of intermetallic phases. This approach overcomes limitations of traditional two-dimensional metallographic methods, offering a more comprehensive understanding of the complex three-dimensional structures formed during solidification.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01803-3
As a green sustainable alternative technology, synthesizing nitrate by electrocatalytic nitrogen oxidation reaction (NOR) can replace the traditional energy-intensive Ostwald process. But low nitrogen fixation yields and poor selectivity due to the high bond energy of the N≡N bond and competition from the oxygen evolution reaction in the electrolyte restrict its application. On the other hand, two-dimensional (2D) PdS2 as a member in the family of group-10 novel transition metal dichalcogenides (NTMDs) presents the interesting optical and electronic properties due to its novel folded pentagonal structure, but few researches involve to its fabrication and application. Herein, unique imitating growth feature for PdS2 on different 2D substrates has been firstly discovered for constructing 2D/2D heterostructures by interface engineering. Due to the different exposed chemical groups on the substrates, PdS2 grows as the imitation to the morphologies of the substrates and presents different thickness, size, shape and the degree of oxidation, resulting in the significant difference in the NOR activity and stability of the obtained composite catalysts. Especially, the thin and small PdS2 nanoplates with more defects can be obtained by decorating poly(1-vinyl-3-ethylimidazolium bromide) on the 2D substrate, easily oxidized during the preparation process, resulting in the in situ generation of SO4^2−, which plays a crucial role in reducing the activation energy of the NOR process, leading to improved efficiency for nitrate production, verified by theoretical calculation. This research provides valuable insights for the development of novel electrocatalysts based on NTMDs for NOR and highlights the importance of interface engineering in enhancing catalytic performance.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01759-4
Silicon suboxide (SiOx, 0<x<2) is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries. Nevertheless, the huge volume change and rapid capacity decay of SiOx electrodes during cycling pose huge challenges to their large-scale practical applications. To eliminate this bottleneck, a dragonfly wing microstructure-inspired polymer electrolyte (denoted as PPM-PE) is developed based on in-situ polymerization of bicyclic phosphate ester- and urethane motif-containing monomer and methyl methacrylate in traditional liquid electrolyte. PPM-PE delivers excellent mechanical properties, highly correlated with the formation of a micro-phase separation structure similar with dragonfly wings. By virtue of superior mechanical properties and the in-situ solidified preparation method, PPM-PE can form a 3D polymer network buffer against stress within the electrode particles gap, enabling much suppressed electrode volume expansion and more stabilized solid electrolyte interface along with evidently decreased electrolyte decomposition. Resultantly, PPM-PE shows significant improvements in both cycling and rate performance in button and soft package batteries with SiOx-based electrodes, compared with the liquid electrolyte counterpart. Such a dragonfly wing microstructure-inspired design philosophy of in-situ solidified polymer electrolytes helps facilitate the practical implementation of high-energy lithium batteries with SiOx-based anodes.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.10.007
Deep-sea mining has emerged as a critical solution to address global resource shortages; however, the mechanical interaction between tracked mining vehicles (TMVs) and soft seabed sediments presents fundamental engineering challenges. This study establishes a multiscale modelling framework coupling the discrete element method (DEM) with multi-body dynamics (MBD) to investigate track-seabed dynamic interactions across three operational modes: flat terrain, slope climbing, and ditch surmounting. The simulation framework, validated against laboratory experiments, systematically evaluates the influence of grouser geometry (involute, triangular, and pin-type) and traveling speed (0.2–1.0 m/s) on traction performance, slip rate, and ground pressure distribution. Results reveal rate-dependent traction mechanisms governed by soil microstructural responses: higher speeds enhance peak traction but exacerbate slip instability on complex terrain. Critical operational thresholds are established—0.7 m/s for flat terrain, ≤0.5 m/s for slopes and ditches—with distinct grouser optimization strategies: involute grousers achieve 35%–40% slip reduction on slopes through progressive soil engagement, while triangular grousers provide optimal impact resistance during ditch crossing with 30%–35% performance improvement. These findings provide quantitative design criteria and operational guidelines for optimizing TMV structural parameters and control strategies, offering a robust theoretical foundation for enhancing the performance, safety, and reliability of deep-sea mining equipment in complex submarine environments.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3050-1
The development of stretchable conductors with high deformation, conductivity, and thermal conductivity using liquid metal (LM) has sparked widespread interest in the fields of flexible electronics, electromagnetic interference (EMI), and multifunctional materials. However, fabricating desirable shielding materials by directly coating LMs on soft polymer substrates remains a challenge because of the huge surface tension and weak wettability of LMs. In this study, Ga-based composite paste is prepared from a mixture of Ga and diamond nonmetallic particles through ultrasonic fragmentation. At various temperatures, the resulting LM composite putty (LMP) exhibits soft and hard properties and can thus be molded into specific shapes according to application needs. In addition, the composite can be easily coated onto polymer substrates, such as thermoplastic polyurethane (TPU) elastomer. The fabricated LMP–TPU exhibits an impressive shape deformation capacity of 1100%, demonstrating exceptional tensile properties and achieving electromagnetic interference–shielding effectiveness of up to 52 dB. Furthermore, it retains an ultrahigh conductivity of 20000 S/m, even under a strain of 600%. This feature further makes it a highly competitive multifunctional material.