Weiyan Lu

Safe long-term storage of spent nuclear fuel requires materials that combine high neutron absorption with excellent corrosion resistance. In this study, two Gd-doped Fe-based amorphous coatings (2X5 + Gd and PC + Gd) containing 6.0 wt.% Gd were fabricated by high-velocity air–fuel (HVAF) spraying. The coatings exhibit macroscopic neutron absorption cross-sections 16.8 and 15.8 times that of borated stainless steel with a B content of 0.6 wt.%, respectively. Electrochemically, both coatings show spontaneous passivation and superior localized corrosion resistance, with PC + Gd outperforming 2X5 + Gd due to a Cr₂O₃-enriched passive film facilitated by P addition. A unique “dissolution–passivation” mechanism governs corrosion: Gd particles dissolve preferentially as anodes, while the amorphous matrix rapidly repassivates, ensuring durable protection. This work provides a viable strategy for designing high-performance neutron-absorbing composite coatings.

Lightweight refractory high-entropy alloys (HEAs) are promising for engineering applications, yet the effect of Al addition on their corrosion resistance remains unclear. In this work, Ti3Zr1.5Nb1V1Alx (x=0, 0.5, 1) HEAs with single BCC structure were systematically investigated. Electrochemical results show that increasing Al content progressively deteriorates the corrosion resistance, shifting the pitting morphology from random distribution to preferential grain boundary attack. Mechanistic analysis reveals that Al incorporation introduces Al2O3 into the passive film while reducing beneficial high-valence oxides (Tiox4+, Nbox5+, and Vox5+), leading to increased donor density and reduced film compactness. Meanwhile, Al segregation at grain boundaries creates weak sites which promoting localized dissolution. These findings provide critical guidance for optimizing Al content in corrosion-resistant lightweight HEAs.

Lightweight refractory high-entropy alloys (HEAs) are promising for engineering applications, yet the effect of Al addition on their corrosion resistance remains unclear. In this work, Ti3Zr1.5Nb1V1Alx (x=0, 0.5, 1) HEAs with single BCC structure were systematically investigated. Electrochemical results show that increasing Al content progressively deteriorates the corrosion resistance, shifting the pitting morphology from random distribution to preferential grain boundary attack. Mechanistic analysis reveals that Al incorporation introduces Al2O3 into the passive film while reducing beneficial high-valence oxides (Tiox4+, Nbox5+, and Vox5+), leading to increased donor density and reduced film compactness. Meanwhile, Al segregation at grain boundaries creates weak sites which promoting localized dissolution. These findings provide critical guidance for optimizing Al content in corrosion-resistant lightweight HEAs.

A four-order “orientation-clustering-stiffness-damage” coupling framework is proposed for 28–30 vol% carbon-fiber/epoxy short-fiber composites (7 μm nominal fiber diameter, 3–5 mm chopped length), enabling accurate cross-scale failure prediction spanning from 60 μm single-fiber interfacial debonding regions up to 300 μm component-level representative volume elements that cover the full statistical distribution of fiber orientation and spatial arrangement. Twenty-one 30 × 30 × 30 mm ³ cubic specimens were in-situ imaged under quasi-static loading via synchrotron radiation Micro-CT at 0.5 μm voxel spacing, delivering approximately 1 μm effective spatial resolution after standard modulation transfer function deconvolution and ring-artifact suppression processing. The tomographic finite-element analysis workflow was fully synchronized to a pre-calibrated six-channel acoustic-emission array with 120 dB gain and 100 kHz–1 MHz bandwidth, where 15 specimens were exclusively used for multi-parameter model calibration through a genetic algorithm optimization loop, while the remaining six completely independent specimens were adopted for rigorous blind validation under uniaxial tension, biaxial compression and in-plane shear loading conditions. This framework achieves a tensile modulus prediction error below 5% and over 92% acoustic-emission hit event agreement on the fully unseen validation dataset, which significantly outperforms conventional Mori-Tanaka mean-field homogenization and periodic representative-volume-element homogenization methods by reducing prediction deviation by more than 40%. By embedding high-order orientation tensors, statistical fiber clustering spectral descriptors and gradient-sensitive non-local damage variables into a single physically interpretable constitutive kernel, the framework delivers an experimentally calibratable, highly scalable and transferable modeling paradigm, holding great practical application potential for composite process reverse design in aerospace and automotive lightweighting industries.

Lightweight refractory high-entropy alloys (HEAs) are promising for engineering applications, yet the effect of Al addition on their corrosion resistance remains unclear. In this work, Ti3Zr1.5Nb1V1Alx (x=0, 0.5, 1) HEAs with single BCC structure were systematically investigated. Electrochemical results show that increasing Al content progressively deteriorates the corrosion resistance, shifting the pitting morphology from random distribution to preferential grain boundary attack. Mechanistic analysis reveals that Al incorporation introduces Al2O3 into the passive film while reducing beneficial high-valence oxides (Tiox4+, Nbox5+, and Vox5+), leading to increased donor density and reduced film compactness. Meanwhile, Al segregation at grain boundaries creates weak sites which promoting localized dissolution. These findings provide critical guidance for optimizing Al content in corrosion-resistant lightweight HEAs.

Laser-remelted Stellite alloys are widely used in wear-resistant components owing to their excellent wear resistance. However, the relationship linking carbide type and volume fraction with wear behavior remains unclear. To address this, three alloys with different carbon and tungsten contents in Stellite 1, Stellite 6, and Stellite 12 were deposited on AISI 1045 steel by plasma transferred arc (PTA) cladding and then laser remelted. It is found that the carbide characteristics differ markedly after remelting, with Stellite 1 retaining the highest M₇C₃ content and the most pronounced size refinement, whereas both Stellite 6 and Stellite 12 undergo near-complete carbide dissolution. The wear results show that the remelted Stellite 1 achieves the lowest wear rate of 0.46 × 10-5 mm³/(N·m) among the three alloys, with a friction coefficient of 0.52. The difference in wear behavior arises from carbide-dependent elastic contact responses and subsurface strain partitioning. Elastic contact simulations combined with KAM analysis reveal that, compared with the other two alloys, the higher-modulus remelted Stellite 1 develops a distinct hard-contact state, which confines intense strain to a thin surface layer and thereby minimizes subsurface damage. This work provides a mechanistic understanding of how carbide features govern the wear behavior of laser-remelted Stellite alloys.

Borated stainless steels (BSSs) with high boron content are essential for neutron absorption in spent nuclear fuel wet storage, but they suffer from severe pitting corrosion resistance. This work investigates the effect of hot rolling degree on the pitting resistance of a BSS with high B content. Results indicate that increasing rolling reduction markedly enhances the pitting resistance of BSS. The improved corrosion resistance is mainly attributed to two factors. First, hot rolling refines the grain structure, thereby facilitating the formation of a denser and Cr-enriched passive film through accelerated film growth kinetics and enhanced Cr diffusion along grain boundaries. Second, hot rolling suppresses pit initiation by reducing both the width and number of Cr-depleted regions at the γ/(Cr, Fe)2B interfaces. This work demonstrates that high-degree hot rolling is an effective pathway to improving corrosion resistance of high-boron BSS for wet storage applications.

Borated stainless steels (BSSs) with high boron content are essential for neutron absorption in spent nuclear fuel wet storage, but they suffer from severe pitting corrosion resistance. This work investigates the effect of hot rolling degree on the pitting resistance of a BSS with high B content. Results indicate that increasing rolling reduction markedly enhances the pitting resistance of BSS. The improved corrosion resistance is mainly attributed to two factors. First, hot rolling refines the grain structure, thereby facilitating the formation of a denser and Cr-enriched passive film through accelerated film growth kinetics and enhanced Cr diffusion along grain boundaries. Second, hot rolling suppresses pit initiation by reducing both the width and number of Cr-depleted regions at the γ/(Cr, Fe)2B interfaces. This work demonstrates that high-degree hot rolling is an effective pathway to improving corrosion resistance of high-boron BSS for wet storage applications.