PurposeThis study aims to clarify the effect of cerium (Ce) content on passive film stability and localized corrosion behavior of a Cr-containing alloy in hypersaline seawater, with particular emphasis on the differences between aerated and deaerated conditions.Design/methodology/approachAlloys with different Ce contents were prepared and exposed to NaCl solutions with chloride concentrations up to 50,000 ppm under aerated and deaerated environments. Microstructural evolution and precipitation behavior were characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive spectroscopy. Corrosion behavior was evaluated using open-circuit potential, electrochemical impedance spectroscopy, potentiodynamic polarization, surface morphology analysis and X-ray photoelectron spectroscopy characterization of passive films.FindingsModerate Ce addition (0.5 Wt.%) significantly refines the microstructure, suppresses harmful precipitates and promotes the formation of compact, Cr-rich passive films, resulting in enhanced corrosion resistance under both aerated and deaerated conditions. Excessive Ce addition induces Ce-rich and Cr/Mo-rich precipitates, increasing electrochemical heterogeneity and accelerating pitting corrosion, especially in oxygen-deficient environments. Deaerated conditions markedly weaken passive film stability and facilitate chloride penetration, leading to more severe localized corrosion.Originality/valueThis work provides a systematic comparison of Ce-regulated corrosion mechanisms under aerated and deaerated conditions in hypersaline seawater, revealing the synergistic roles of microstructure, precipitation evolution and passive film chemistry in governing localized corrosion resistance.

This study developed a metal-modified fluoroethylene vinyl ether (FEVE) organic coating on 6061 aluminum alloy, supported by a micro-arc oxidation (MAO) pretreatment layer, to enhance corrosion resistance and antifouling performance in marine environments. The MAO layer offered initial ceramic protection, reducing i corr from 2.46 & times; 10-6 to 6.27 & times; 10-7 A cm- 2. FEVE fluorocarbon resin acting as the primary functional barrier provided a dense, low-polarity outer layer, whereas La3+/Ho3+ ions coordinated with the polymer matrix and deposited in situ as metal oxides at micro-defects, further decreasing i corr to 1.62 & times; 10-9 A cm- 2. Additionally, the combined effects of FEVE hydrophobicity, metal ion activity, and Ag+/Cu2+ release effectively inhibited fungal growth and diatom adhesion, maintaining stable antifouling performance over 7-14 days. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) results confirmed uniform metal modification dispersion and improved organic/inorganic interfacial densification. Overall, the MAO-FEVE-La/Ho system demonstrates a polymer-driven barrier-defect-sealing-ion-assisted antifouling mechanism, offering strong potential for long-term marine applications. (sic)(sic)(sic)(sic) 6061 (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(MAO)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)-(sic)(sic)(sic)(sic)(FEVE)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).MAO (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(i corr)(sic) 2.46 & times; 10-6 A cm-2 (sic)(sic)(sic) 6.27 & times; 10-7 A cm-2.(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) FEVE (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic) La3+/Ho3+ (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic) i corr (sic)(sic)(sic) 1.62 & times; 10-9 A cm-2.(sic)(sic),FEVE (sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic) Ag+/Cu2+ (sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic) 7-14 (sic) (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic)(sic)(sic)(sic)(SEM),(sic)(sic)(sic)(sic) X (sic)(sic)(sic)(EDS)(sic) X (sic)(sic)(sic)(sic)(XRD)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)/(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).(sic)(sic)(sic)(sic),MAO-FEVE-La/Ho (sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic),(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic)(sic).

Magnesium-based alloys are attractive candidates for biodegradable orthopedic implants owing to their excellent biocompatibility and bone-like mechanical properties; however, their excessively rapid corrosion in physiological environments often causes premature loss of mechanical integrity and adverse local reactions, limiting clinical translation. In this study, a micro-arc oxidation (MAO) ceramic layer and an outer polylactic acid (PLA) coating were constructed on a Magnesium alloy, and ZnTe particles were incorporated into the PLA layer at varying concentrations to obtain a ZnTe doped MAO/PLA composite coating with enhanced integrity and antibacterial function. The microstructure, coating morphology, and phase composition were characterized, and corrosion behavior in Hank's simulated body fluid was assessed by open-circuit potential and electrochemical impedance spectroscopy. Results show that the MAO layer forms a strongly adherent oxide barrier while the PLA topcoat effectively seals MAO micro-pores; ZnTe addition further improves coating compactness, leading to markedly increased potential stability and charge-transfer resistance relative to ZnTe-free coatings, indicating superior corrosion resistance. Immersion tests reveal that ZnTe incorporation enhances the buffering capacity of the system, mitigating the pH decrease associated with PLA hydrolysis. Antibacterial assays demonstrate a bactericidal rate exceeding 99% for ZnTe-containing coatings. Collectively, the ZnTe-doped MAO/PLA composite coating provides synergistic corrosion protection and robust antibacterial activity, offering a promising surface-engineering route to improve the long-term reliability of biodegradable magnesium implants.

With the growing concern for environmental sustainability and energy demand in recent years, microbial fuel cells (MFCs) have emerged as an innovative environmental technology that converts organic waste into green energy through microbial metabolism. This review provides an overview following the structure of ‘mechanism–model–materials–application', analyzes the operational principles and practical applications of MFCs, and focuses on cutting-edge technological advances that enhance the application capabilities of MFCs. The mechanisms of MFCs' operation are summarized, including anaerobic cellular respiration and extracellular electron transfer processes. Subsequently, the development of mechanism & application-oriented MFC models is reviewed. The roles and advancements of various substrate materials, including methods for modifying them to enhance the overall performance of MFCs, are evaluated based on numerous laboratory studies on electrode materials. The potential applications of MFCs in wastewater treatment, electricity production, and renewable energy recovery are discussed. The progress of MFCs in small and medium-sized electronic devices, such as biosensors and wearable technology, is reported. In particular, MFCs will play a significant role in the development and utilization of marine resources, as well as in the synthesis and corrosion protection of advanced marine materials. The long-term operation of MFCs in marine environments, by utilizing local marine microorganisms and sediment resources, can effectively facilitate marine environmental protection and resource development in a location-specific manner. Through interdisciplinary collaboration and cutting-edge research, MFCs are poised to become the sustainable solution for transitioning from energy production and pollution treatment to a green bioeconomy.

This study investigated the electrochemical, microbial, and metagenomic characteristics of microbial fuel cells (MFCs) operated at different poised anode potentials (-0.4 V, 0 V, and + 0.4 V vs. Standard Hydrogen Electrode), inoculated with the sulfate-reducing bacteria (SRB)-enriched consortium from real shale gas fracturing flowback water. Marked performance differences were observed across the individually operated reactors after acclimation, with the reactor poised at -0.4 V showing the highest sulfate removal efficiency (75%) and power density (0.63 W/m2). Electrochemical analyses indicated the highest electrochemical activity in the -0.4 V anode biofilm. Metagenomic analysis revealed that Nitratidesulfovibrio vulgaris (N. vulgaris) was substantially more abundant in the -0.4 V reactor (16%) than in the other reactors, where it was the dominant SRB taxon. Functional gene profiling of the dissimilatory sulfate reduction (DSR) and extracellular electron transfer (EET) systems showed that N. vulgaris was the taxon to which DSR genes and the pilin subunit genes flp and pilA were predominantly assigned based on best-hit annotation, suggesting a possible direct EET route via a pilus system. Furthermore, the fermentative genus Trichococcus also showed higher relative abundance in this reactor, and nfrA1 was predominantly assigned to this taxon (best-hit annotation), pointing to a potential role in flavin-mediated indirect EET. Collectively, these observations indicate that the -0.4 V reactor was associated with a distinct community structure and functional gene abundance profile, providing a putative metabolic model that may guide future exploration of SRB-MFCs targeting sulfate-rich wastewater.

To address the poor interfacial compatibility between porous silica (pSiO(2)) and waterborne epoxy (WEP) matrix, we investigate the interfacial modulation effect of hexamethyldisilazane (HMDS) functionalization on pSiO(2)/WEP nanocomposites. The optimal comprehensive performance is achieved at 2 wt% HMDS-pSiO(2) loading: the water contact angle increases from 75.4 degrees to 84.4 degrees, the interfacial adhesion strength improves by 52.6% to 5.8 MPa, and the low-frequency impedance modulus (|Z|(0.01)Hz) reaches 1.77 & times; 10(9) Omega cm(2), which is two orders of magnitude higher than pure WEP coating (6.2 & times; 10(7) Omega cm(2)) and similar to 1.5-2 times higher than most recently reported state-of-the-art modified SiO2/WEP systems. The coating also maintains excellent long-term stability, retaining an impedance modulus of 4.5 & times; 10(8) Omega cm(2) after 30 days of immersion in 3.5 wt% NaCl solution. This significant performance enhancement originates from the synergistic corrosion protection mechanism combining a physical barrier with tortuous diffusion paths and in-situ chemical passivation via an iron silicate self-healing layer. This work provides a facile and effective strategy for designing high-performance eco-friendly waterborne anticorrosive coatings for industrial marine and petrochemical applications.

A functional composite coating system was developed on VW75 magnesium alloy to address the trade-off between corrosion resistance and electrical conductivity. A micro-arc oxidation (MAO) inner layer incorporating Ta2O5 particles was first fabricated, followed by the deposition of an epoxy resin topcoat doped with PEDOT: PSS and cobalt (Co) powder. The microstructure, phase composition, and electrochemical properties of the composite coatings were systematically characterized. The results indicated that the incorporation of Ta2O5 particles significantly enhanced the compactness of the MAO layer, with optimal corrosion resistance achieved at a Ta2O5 concentration of 6 g/L. When the concentration of Ta2O5 is 6 g/L, the pore size distribution of the coating is moderate, which can form a strong bonding force with the epoxy coating. The subsequent application of the modified epoxy topcoat further augmented the protective performance via a pore-sealing effect. Notably, the corrosion resistance was positively correlated with the content of dopants. Furthermore, the PEDOT: PSS and Co fillers facilitated the formation of a conductive percolation network within the epoxy matrix, thereby imparting excellent electrical conductivity to the composite. These findings demonstrate the potential of this dual-layer coating strategy for protecting magnesium alloys in harsh marine environments.

Marine monitoring equipment under prolonged seawater immersion faces severe challenges from biofouling and microbiologically influenced corrosion (MIC), which compromise operational reliability. Herein, composite coatings were synthesized using water-based epoxy-modified organosilicone resin as the matrix, incorporating three functionalized graphene oxide (GO) fillers: carboxylated (CGO), hydroxylated (OHGO), and aminated (NGO). Comprehensive characterizations and evaluations of adhesion, corrosion resistance, antimicrobial activity, and visible transmittance demonstrate that CGO composite coatings outperform OHGO and NGO counterparts, attributed to two key mechanisms: (1) the highest polarity of carboxyl groups (1.8-2.1 D) promotes electron transfer and reactive oxygen species (ROS) generation, inducing bacterial oxidative stress; (2) enhanced CGO-resin interfacial compatibility forms a denser physical barrier against corrosive media. Specifically, the CGO-15 coating (0.15 wt% CGO) achieves optimal performance: adhesion strength of 3.55 MPa, low-frequency impedance modulus (|Z|(0).(1)Hz) of 6.5 x 10(6) Omegacm(2) (two orders of magnitude higher than the pure silicone resin coating), over 90 % inhibition of sulfate-reducing bacteria (SRB), initial visible transmittance of 96 %, and retention of > 85 % transmittance after 14 days of immersion in SRB-containing medium. Flow cytometry confirms that intracellular ROS levels in SRB exposed to CGO-15 are 5-fold higher than those in the blank group, verifying ROS-mediated bacterial metabolic disruption. This work establishes a clear structure-property relationship for GO-functionalized marine coatings, providing a sustainable solution integrating high transparency, corrosion resistance, and antifouling performance for marine monitoring equipment.

Micro-arc oxidation (MAO) coatings were prepared on 6061 aluminum alloy in an Nb-containing silicate-phosphate electrolyte to clarify the coupled effects of voltage and frequency on microporous architecture and corrosion protection in natural seawater. A 3 × 3 parameter matrix was designed using voltages of 400, 500, and 600 V and frequencies of 300, 600, and 900 Hz. SEM and image analysis showed that all coatings exhibited discharge-induced micropores, with most equivalent pore diameters concentrated at 0.4–1.2 μm. Increasing voltage enhanced plasma discharge, promoted coating growth and oxide crystallization, and enlarged surface pores, increasing the coating thickness from 3.25 ± 0.25 μm at 400 V-300 Hz to 6.61 ± 0.25 μm at 600 V-300 Hz. Increasing frequency dispersed micro-discharges and reduced open porosity, with the lowest porosity obtained at 600 V-900 Hz. EDS and XRD confirmed the incorporation of Si, P, and Nb species into alumina-based coatings mainly composed of γ-Al₂O₃. Electrochemical results showed that corrosion resistance was governed by coating thickness, pore connectivity, and inner barrier-layer continuity rather than surface porosity alone. The 600 V-300 Hz coating exhibited the strongest initial protection, with the lowest corrosion current density of 1.097 × 10−11 A cm−2 and the highest initial oxide-film resistance of 2.690 × 108 Ω cm2. Time-dependent EIS further showed that the 600 V-900 Hz coating retained better impedance stability after 72 h immersion owing to its refined pore structure and reduced pore connectivity.

This study systematically investigates the influence of cerium addition on the microstructural evolution and corrosion behavior of super austenitic stainless steel subjected to solution treatment in simulated alkaline seawater environments. The results demonstrate that appropriate Ce addition significantly enhances corrosion resistance, with the optimal performance observed at 1.0 wt% Ce. At this concentration, grain refinement and improved microstructural homogeneity are achieved, leading to enhanced stability of the passive film. Electrochemical analyses, including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization tests, reveal reduced corrosion current density and improved passivation behavior over a temperature range of 25-75 degrees C. These results indicate that Ce-modified super austenitic stainless steel exhibits superior corrosion resistance and structural stability in alkaline chloride-containing environments, suggesting its strong potential as a corrosion-resistant metallic material for alkaline seawater electrolysis environments.

To improve the corrosion and wear resistance of high-entropy alloy (HEA) coatings to meet the extreme marine working environment, W was introduced into the FeCoNiCrAl coating system, and FeCoNiCrAl and FeCoNiCrAlW coatings were fabricated by plasma spraying. Microstructure, corrosion behavior, tribocorrosion performance, and interfacial electronic structure were systematically investigated. The results show that the addition of W element significantly improves the comprehensive properties of the coatings. The FeCoNiCrAlW coating achieved a 30.59% increase in hardness, while the coating porosity decreased by 36.25%. Compared with FeCoNiCrAl HEA coatings, the FeCoNiCrAlW HEA coatings exhibit a dramatic reduction in corrosion current density from 1.80 & times; 10-5 A center dot cm-2 to 5.72 & times; 10-7 A center dot cm-2, confirming its superior corrosion resistance. The wear rate is reduced from 4.84 & times; 10-6 mm3 center dot N-1 center dot m-1 to 3.75 & times; 10-6 mm3 center dot N-1 center dot m-1 in 3.5 wt% NaCl solution. FeCoNiCrAlW coating exhibits a lower oxidation tendency after tribocorrosion. W incorporation regulates the electronic structure of the alloy system and reduces interfacial charge transfer, indicating superior interfacial stability, thereby suppresses Cl-induced corrosion and oxidation. These effects inhibit the formation of corrosion products and material spallation, ultimately leading to the improved tribocorrosion resistance of the FeCoNiCrAlW coating.

Nacre-inspired coatings reinforced with amino-functionalized boron nitride nanosheets (NH2-BNNSs) were developed in this work. A hierarchical "brick and mortar" structure, where NH2-BNNSs act as "bricks" and epoxy resin act as "mortar", was developed attributed to electrostatic repulsion between NH2-BNNSs modified by sodium carboxymethyl cellulose. In nacre-inspired coatings, penetration path of corrosive species must travel to reach metal surface was extended significantly, leading to hindered metal corrosion. Electrochemical impedance spectroscopy demonstrated |Z|f=0.01 Hz of aluminum alloy (AA5052) covered by nacre-inspired coating (NC-20) was 4 orders of magnitude higher than that of AA5052 covered by pure epoxy coating after 84 days of exposure in NaCl solution.

The limited engineering applications of magnesium alloys due to their inadequate corrosion resistance have prompted extensive research. Systematic analysis of corrosion products holds significant scientific value for elucidating corrosion mechanisms, evaluating material performance, optimizing protective processes, and guiding alloy design. This review summarizes recent studies on the corrosion behavior of magnesium alloys in marine atmospheres, industrial environments, and biomedical settings. In marine environments, the synergy between atmospheric temperature/humidity and chloride deposition rate critically influences corrosion kinetics. In industrial settings, pollutant gases and particulate matter markedly accelerate corrosion through surface adsorption. In biomedical scenarios, the interaction between alloys and body fluids, along with tissue contact, leads to more complex micro-scale corrosion phenomena. This study focuses on the distinct corrosion characteristics of magnesium alloys across various service environments and provides an in-depth analysis of the mechanisms by which different factors affect their corrosion behavior. Based on this, key elements governing alloy performance are comprehensively considered to develop tailored alloy designs for specific applications, aiming to create novel magnesium alloys with excellent corrosion resistance that are highly compatible with their intended environments. Furthermore, multi-scale characterization techniques are employed to systematically analyze the corrosion products of magnesium alloys, offering multidimensional insights into the nature of corrosion in resistant alloys. These contents aim to enhance the understanding of corrosion mechanisms and provides important theoretical support for subsequent composition optimization, process improvement, and overall performance enhancement of corrosion-resistant magnesium alloys.

Aluminum alloys used in marine engineering face the dual threats of solar radiation induced thermal loading and corrosion from chloride rich marine atmospheres. To address these challenges, we designed a nacre-inspired composite coating that integrates passive radiative cooling with superior anti-corrosion performance. The coating comprises two primary components, a bottom emission layer and a top reflective layer. The emission layer is constructed via layer-by-layer (LbL) assembly of cationic chitosan containing dispersed boron nitride nanosheets (BN@CS) and anionic poly(sodium 4-styrenesulfonate) (PSS). The top reflective layer consists of TiO2 nanoparticles dispersed in a fluorocarbon (FEVE) resin. The emission layer mimics the structure of nacre, creating an extended tortuous path for corrosive media. Electrochemical impedance spectroscopy (EIS) results confirm the optimal coating (C-40) retains a low-frequency impedance modulus of 4.66 & times; 1010 Omega & sdot;cm2, which is four orders of magnitude higher than a conventional FEVE coating after 60 days of immersion in 3.5 wt% NaCl solution. Concurrently, the high refractive index of TiO2 ensures efficient scattering of sunlight (0.3-2.5 mu m), while the h-BN nanosheets provide a high and selective thermal emissivity (approximate to 88%) within the atmospheric transparency window (8-13 mu m). This synergistic design yields an outstanding radiative cooling effect, achieving a temperature reduction of 12.7 degrees C under outdoor conditions. This composite coating, integrating corrosion protection and radiative cooling functionalities, offers a viable pathway to enhance the durability of aluminum alloy components in harsh coastal environments.

Marine equipment faces numerous threats during service, such as metal corrosion and the attachment of marine fouling organisms. Therefore, the development of multifunctional organic protective coatings is crucial. In this study, a UV-curable, photothermal-responsive PHFBA-IBOA/Bi2WO6@CuS (PFI/BC) polyacrylate organic composite coating was successfully synthesized and evaluated for its structure and properties. The composite coating exhibits a time-efficient preparation process, high photothermal self-healing efficiency, ultra-long anticorrosion capacity and outstanding antifouling ability. The results show that the temperature at the center of the PFI/BC composite coating reaches 133.1 degrees C upon exposure to the NIR laser at 808 nm of 1.5 W & sdot;cm-2. This constitutes a 225% increase relative to the pure resin. The self-healing of the PFI/BC composite coating can be completed after 45 s of irradiation. After 90 d of EIS test, the |Z|0.01Hz of the PFI/BC composite coating can reach 1.3 & times; 108 Omega & sdot;cm2, which proves its excellent anticorrosion performance. After 336 h of algae attachment experiment, the PFI/BC composite coating exhibited the lowest level of Platymonas subcordiformis and Phaeodactylum tricornutum adhesion, demonstrating long-term antifouling capability. This research provides a promising strategy for the development of multifunctional organic protective coatings.

TiO2-based n-type semiconductor materials are promising photoanodic materials in photoelectrochemical (PEC) cathodic protection, if only their dependence to hole scavengers can be overcome. In this study, ZnAl-layered double hydroxide/TiO2 composites (Ti-Z/A) were prepared hydrothermally. The PEC cathodic protection performance of the composites was then tested in NaCl solution, without the use of any hole scavengers. Open circuit potential (OCP)-time (OCP-t) and current-time (i-t) measurements indicated that the composite with a Zn: Al ratio of 3:1 exhibited the most effective cathodic protection of 304 stainless steel (304 SS), as evidenced by the largest negative shift in OCP (-350 mV) and the highest photocurrent density (10 mu A cm-2). An 85-h intermittent illumination test demonstrated the long-term stability of the Ti-Z/A photoanode. Reasons for the non-dependence of Ti-Z/A on hole scavengers were discussed in detail. The result indicated a Z-scheme heterojunction between ZnAl-LDH and TiO2 was formed, which preserved powerful redox potentials (e.g., highly oxidizing holes and highly reducing electrons). The highly oxidizing holes can be directly consumed by ambient substances (e.g., H2O, OH-). The result demonstrated a direct, rapid and thorough consumption of photo-generated holes is essential to maintain long-term performance of TiO2 based photoanodes.

Microarc Oxidation (MAO) coatings on Al-10wt.%La alloy were synthesized by incorporating varying concentrations of tungsten carbide (WC) into the electrolyte. The micromorphology, elemental distribution, three-dimensional morphology, physical phase composition, and corrosion resistance of the resulting MAO coatings were systematically analyzed and characterized. Our findings indicate that the surface micropores, pore diameter, and roughness of the MAO coatings exhibited a biphasic response to the WC concentration, with a decrease followed by an increase as the WC concentration increased. Concurrently, the coating thickness initially increased and then decreased with increasing WC concentration. The MAO coatings significantly enhanced the corrosion resistance of the Al-10La alloy compared to the uncoated substrate. The variation in WC concentration altered the densification of the coatings, which in turn influenced their corrosion resistance. Notably, at a WC concentration of 4 g/L, the MAO coatings demonstrated optimal corrosion resistance.

Developing polyurethane coatings that simultaneously exhibit rapid self-healing, high mechanical robustness, and long-term corrosion resistance remains a significant challenge for protective applications. Herein, a Ti3C2Tx@ZnIn2S4 (Ti3C2Tx@ZIS) heterojunction was synthesized via a solvothermal strategy and incorporated into a disulfide-containing polyurethane matrix to fabricate a multifunctional coating. The Ti3C2Tx@ZIS heterojunction exhibited excellent photothermal conversion capability, which efficiently activated dynamic disulfide bond exchange and enabled rapid self-healing of surface damage within 20 s under 808 nm laser irradiation. Benefiting from the synergistic reinforcement of the heterojunction filler and the dynamic polymer network, the tensile strength and toughness of the polyurethane reached 36.37 MPa and 140.61 MJ·m−3, respectively. In situ morphological observation, atomic force microscopy, and small-angle X-ray scattering revealed that the Ti3C2Tx nanosheets effectively regulated stress transfer and promoted the orientation and redistribution of polyurethane molecular chains during deformation, thereby enhancing the mechanical performance. Furthermore, the coating maintained an impedance modulus of approximately 1010 Ω·cm2 after 90 days of immersion, demonstrating outstanding long-term corrosion protection. This work provides an effective strategy for constructing rapidly self-healing, mechanically robust, and corrosion-resistant polyurethane coatings for demanding engineering environments.

B4C/Al neutron absorber materials are critical for the criticality safety of spent nuclear fuel wet storage, yet their corrosion-induced degradation poses a significant challenge to long-term operational reliability. This study systematically investigated the corrosion behavior and failure mechanism of a commercial B4C/Al composite during long-term immersion in a simulated spent fuel pool environment (2700 ppm boric acid at 40 degrees C) via microstructural characterization and electrochemical analyses. Results indicate that the corrosion product layer exhibits a decelerating growth trend, and is mainly composed of non-protective aluminum oxides and hydroxides. Scanning kelvin probe (SKP) and in-situ scanning vibrating electrode technique (SVET) mapping revealed that preferential corrosion occurs at the interface, driven by the micro-galvanic coupling between the noble B4C particles (micro-cathodes) and the active Al matrix (micro-anodes). The rapid interfacial dissolution undermines the matrix support, causing the neutron-absorbing B4C particles to undergo mechanical loosening and detach along with the shedding of the loose corrosion product layer, thereby posing a potential risk to the material's functional performance.