Coatings

29 pages, 13229 KB

Open AccessArticle

Direct Strength Method for Compression Capacity Assessment of Circular Steel Tubes with Uniform Corrosion Modeled via Wall Thickness Reduction Induced by Coating Degradation in Coastal Atmospheric Environments

by Yuan Wei, Yatao Lin, Congcong Lin, Yingjie Li and Xianbiao Xiao

Coatings 2026, 16(7), 882; https://doi.org/10.3390/coatings16070882 - 22 Jul 2026

Viewed by 620

Abstract

Coastal and offshore steel infrastructures such as transmission towers and wind turbine towers are prone to coating degradation after long-term exposure to salt fog, high humidity, and ultraviolet radiation. The subsequent uniform corrosion significantly reduces the cross-sectional load-carrying capacity and threatens structural safety. [...] Read more.

Coastal and offshore steel infrastructures such as transmission towers and wind turbine towers are prone to coating degradation after long-term exposure to salt fog, high humidity, and ultraviolet radiation. The subsequent uniform corrosion significantly reduces the cross-sectional load-carrying capacity and threatens structural safety. This paper presents a numerical parametric analysis on the compression behavior of circular steel tube (CST) members subjected to uniform corrosion induced by coating failure, based on 18 accelerated corrosion tests. The effectiveness of the wall thickness reduction method for simulating uniform corrosion after coating degradation is verified, and the influence of key parameters on load-carrying capacity degradation is systematically investigated. A simplified formula for elastic local buckling of corroded CSTs is derived, and a direct strength method (DSM) calculation framework considering both global buckling and local–global interactive buckling is established. The results show that the uniform corrosion ratio is the dominant factor affecting load-carrying capacity degradation, while sectional dimension, slenderness ratio, and eccentricity have negligible influence. The proposed DSM method achieves a prediction error within 5% compared with test and numerical results. It is primarily applicable to uniformly corroded steel tubes represented by equivalent wall thickness loss, and its applicability to scenarios with localized corrosion, pitting corrosion, weld-zone corrosion, or non-uniform wall thickness reduction requires further validation. This method provides a rapid and accurate tool for residual load-carrying capacity assessment and life cycle management of coastal steel infrastructures after coating failure. Full article

(This article belongs to the Special Issue Corrosion Characteristics and Surface Protection of Coastal Infrastructure)

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16 pages, 2778 KB

Open AccessArticle

Effect of Sports and Energy Drinks on Surface Roughness of Dental Restorative Materials: An In Vitro Study

by Filip Podgórski, Wiktoria Musyt, Michał Krasowski, Kinga Bociong, Beata Czarnecka and Kacper Nijakowski

Coatings 2026, 16(7), 881; https://doi.org/10.3390/coatings16070881 - 22 Jul 2026

Viewed by 444

Abstract

This study evaluated the effect of sports and energy drinks on the surface roughness of three commonly used restorative dental materials: resin-based composites (RBCs), resin-modified glass ionomer cements (RMGICs), and conventional glass ionomer cements (GICs). Sixty-three A2-shade specimens of each material were fabricated, [...] Read more.

This study evaluated the effect of sports and energy drinks on the surface roughness of three commonly used restorative dental materials: resin-based composites (RBCs), resin-modified glass ionomer cements (RMGICs), and conventional glass ionomer cements (GICs). Sixty-three A2-shade specimens of each material were fabricated, stored in distilled water for 24 h, and then immersed in six commercially available beverages or distilled water (control) for 6, 30, or 60 h. Surface roughness was assessed after each immersion period using contact profilometry, and the effects of material type, immersion medium, and exposure time were compared. Surface roughness increased with longer immersion times for all materials, although the magnitude of change varied significantly among material types. RBCs showed the greatest resistance to surface degradation, whereas RMGICs and particularly GICs exhibited progressively higher roughness values over time. Beverages generally produced greater surface roughness than distilled water, with sugar-containing formulations showing higher roughness values than their sugar-free counterparts. Prolonged exposure to sports and energy drinks may adversely affect the surface integrity of restorative materials. Resin-based composites demonstrated the highest resistance to roughness changes, whereas glass ionomer cements were the most susceptible. Increased surface roughness may contribute to plaque accumulation, staining, and material wear, potentially compromising the long-term clinical performance of restorations. Full article

(This article belongs to the Special Issue Surface Properties of Dental Materials and Instruments, 3rd Edition)

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28 pages, 1818 KB

Open AccessArticle

Coating-Corrosion Coupled Durability Design of Prestressed Rock Bolt Foundations for Coastal Onshore Wind Turbines in Harsh Corrosive Environments

by Jian Xu, Dongpo Dong, Zhiquan Xing, Jing Huang, Jianwei Su, Wenbo Zhou, Da Luo, Ao Zhang, Changqing Bi and Xueyun Xing

Coatings 2026, 16(7), 880; https://doi.org/10.3390/coatings16070880 - 22 Jul 2026

Viewed by 565

Abstract

Under complex terrains and extreme environmental conditions such as high wind speeds, prestressed rock anchor foundations for onshore wind turbines are subjected to multiple coupled adverse effects during long-term service, including cyclic wind loading, temperature variation, groundwater intrusion, and rock mass weathering. These [...] Read more.

Under complex terrains and extreme environmental conditions such as high wind speeds, prestressed rock anchor foundations for onshore wind turbines are subjected to multiple coupled adverse effects during long-term service, including cyclic wind loading, temperature variation, groundwater intrusion, and rock mass weathering. These factors significantly affect structural performance and service life through corrosion and material degradation processes, while conventional design methods mainly focus on ultimate bearing capacity and lack a systematic consideration of corrosion-induced deterioration mechanisms and long-term performance evolution. Without changing the theoretical framework of current design codes, this study introduces a durability-oriented design concept and explicitly incorporates corrosion effects and material degradation into the analytical system of prestressed rock anchor foundations. First, from the perspective of anchor force evolution, a time-dependent analysis method for long-term prestress loss is established, considering the coupled effects of steel corrosion, material relaxation, and cyclic loading. Second, for the mechanical behavior of group anchor systems, a shear capacity model is proposed that accounts for rock mass strength degradation and grout–rock interface deterioration. Meanwhile, the coupling relationship between foundation void development and groundwater seepage is analyzed, revealing its critical role in the corrosion evolution process. On this basis, a coordinated design method for foundation dimensions and prestress parameters is developed to satisfy both load-bearing capacity and durability requirements. Finite element analysis is further conducted to verify the stress and deformation characteristics of the foundation–rock–anchor system under nonlinear conditions. Engineering case studies demonstrate that the proposed method not only meets bearing capacity requirements, but also effectively suppresses void development, reduces corrosion risk, delays structural performance degradation, and improves long-term service reliability. The findings provide a theoretical basis and engineering reference for the durability design and lifecycle performance optimization of prestressed rock anchor foundations for onshore wind power structures in extreme environments. Furthermore, the study underscores the critical role of advanced anti-corrosion coatings and surface protection systems in mitigating the coupled corrosion-degradation mechanisms, aligning with the scope of this Special Issue on corrosion protection and durability of infrastructure in harsh environments. Full article

(This article belongs to the Special Issue Corrosion Characteristics and Surface Protection of Coastal Infrastructure)

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22 pages, 7948 KB

Open AccessArticle

Interfacial Shear Fatigue and Damage Evolution of Epoxy-Emulsified Asphalt Bond Coats Under Coupled Effects of Temperature, Loading Frequency and Stress Level

by Rui Sun, Jiyi Li and Lingyun Kong

Coatings 2026, 16(7), 879; https://doi.org/10.3390/coatings16070879 - 22 Jul 2026

Viewed by 468

Abstract

Interfacial bond failure is a common form of distress in rigid–flexible composite pavements, especially in tunnel environments with harsh service conditions. Epoxy-emulsified asphalt (EEA) is widely used as a high-performance interlayer bond coat, but its dynamic damage evolution under coupled thermomechanical loading remains [...] Read more.

Interfacial bond failure is a common form of distress in rigid–flexible composite pavements, especially in tunnel environments with harsh service conditions. Epoxy-emulsified asphalt (EEA) is widely used as a high-performance interlayer bond coat, but its dynamic damage evolution under coupled thermomechanical loading remains insufficiently characterised. In this work, 45° static oblique shear tests and stress-controlled dynamic shear fatigue tests were performed on a C40 concrete-EEA-asphalt mixture composite system. Tests covered a temperature range of −10 °C to 45 °C, loading frequencies of 1 to 15 Hz, and three stress levels (0.3, 0.4, 0.5). An optimised geometric tangent method (GTM) was adopted to objectively locate the fatigue failure inflexion point, reducing the empirical bias inherent in traditional stiffness degradation analysis. Test results showed that an EEA application rate of 0.8 kg/m² yielded the best overall interface performance, balancing mechanical interlocking and cohesive strength. At this application rate, the interfacial peak shear strength reached 1.72 MPa, with improved interfacial deformation compatibility and energy dissipation capacity. Fatigue damage followed a distinct three-stage stiffness degradation pattern. High temperatures and low loading frequencies accelerated rheological behaviour of the asphalt phase, shortened the stable damage propagation phase, and promoted premature interlayer slippage. Based on the experimental data, a phenomenological fatigue life prediction model was established, incorporating temperature, loading frequency and stress level. The model supports quantitative assessment of progressive interfacial damage and provides practical reference for structural durability design and life-cycle maintenance of composite tunnel pavements. Full article

(This article belongs to the Special Issue Advanced Coating Barriers for the Protection of Reinforced Concrete and Pavement, 3rd Edition)

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1 pages, 124 KB

Open AccessRetraction

RETRACTED: Chmielewski et al. Structure Investigation of Titanium Metallization Coating Deposited onto AlN Ceramics Substrate by Means of Friction Surfacing Process. Coatings 2019, 9, 845

by Tomasz Chmielewski, Michał Hudycz, Arkadiusz Krajewski, Tadeusz Sałaciński, Beata Skowrońska and Rafał Świercz

Coatings 2026, 16(7), 878; https://doi.org/10.3390/coatings16070878 - 22 Jul 2026

Viewed by 350

Abstract

The journal Coatings retracts the article “Structure Investigation of Titanium Metallization Coating Deposited onto AlN Ceramics Substrate by Means of Friction Surfacing Process” [...] Full article

1 pages, 123 KB

Open AccessRetraction

RETRACTED: Mohammadtaheri et al. The Effect of Deposition Parameters on the Structure and Mechanical Properties of Chromium Oxide Coatings Deposited by Reactive Magnetron Sputtering. Coatings 2018, 8, 111

by Masoud Mohammadtaheri, Qiaoqin Yang, Yuanshi Li and Jesus Corona-Gomez

Coatings 2026, 16(7), 877; https://doi.org/10.3390/coatings16070877 - 22 Jul 2026

Viewed by 338

Abstract

The journal retracts the article titled, “The Effect of Deposition Parameters on the Structure and Mechanical Properties of Chromium Oxide Coatings Deposited by Reactive Magnetron Sputtering” [...] Full article

1 pages, 133 KB

Open AccessCorrection

Correction: Faddouli et al. Facile Elaboration of TiO₂-ZnO-Based Low-Cost H₂ Gas Sensors. Coatings 2026, 16, 375

by Ali Faddouli, Youssef Nouri, Bouchaib Hartiti, Youssef Doubi, Mehmet Ertugrul, Ömer Çoban and Hicham Labrim

Coatings 2026, 16(7), 876; https://doi.org/10.3390/coatings16070876 - 22 Jul 2026

Viewed by 255

Abstract

In the original publication [...] Full article

1 pages, 127 KB

Open AccessCorrection

Correction: Zhou et al. Improving Mechanical and Tribological Behaviors of GLC Films on NBR Under Water Lubrication by Doping Ti and N. Coatings 2022, 12, 937

by Zhen Zhou, Yanfeng Han and Jin Qian

Coatings 2026, 16(7), 875; https://doi.org/10.3390/coatings16070875 - 22 Jul 2026

Viewed by 221

Abstract

In the original publication [...] Full article

23 pages, 6867 KB

Open AccessArticle

Effect of Oblique LSP on the Wear Resistance of Plasma-Nitrided H13 Tool Steel

by Longhui Li, Dongyan Lin, Judong Liu, Junying Chen, Zhilong Xu, Shiqi Chen, Qingshan Jiang, Xiuyu Chen, Wenjun Jiang and Wenbin Ma

Coatings 2026, 16(7), 874; https://doi.org/10.3390/coatings16070874 - 21 Jul 2026

Viewed by 384

Abstract

H13 tool steel is widely used in precision injection molds; however, severe wear in confined regions, such as ejector pin holes, limits its service life, while conventional strengthening techniques remain difficult to apply in these areas. In this study, a combined plasma nitriding [...] Read more.

H13 tool steel is widely used in precision injection molds; however, severe wear in confined regions, such as ejector pin holes, limits its service life, while conventional strengthening techniques remain difficult to apply in these areas. In this study, a combined plasma nitriding and oblique laser shock peening (OLSP) treatment was proposed, and the effects of laser incidence angle on microstructure, mechanical properties, and wear behavior were systematically investigated through electron backscatter diffraction (EBSD), X-ray diffraction (XRD) residual stress analysis, and ball-on-disk (BOD) wear tests. The results demonstrate that OLSP promotes grain refinement, dislocation accumulation, and the introduction of high-magnitude compressive residual stress. The NLSP1 sample exhibited the optimum strengthening effect, with a maximum compressive residual stress of −1033 MPa. It also achieved the lowest wear depth, wear volume, and specific wear rate, with a specific wear rate of 1.64 × 10⁻⁶ mm³/(N·m), representing a 54.3% reduction compared with the untreated sample. The enhanced wear resistance was attributed to the synergistic effects of hardness improvement, microstructural refinement, and compressive residual stress. These findings demonstrate that optimizing the laser incidence angle can improve strengthening efficiency and provide an effective strategy for surface modification of critical regions in complex molds. Full article

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36 pages, 2629 KB

Open AccessArticle

Integrated Thermo-Energy and Environmental Assessment of PHA-Based Biopolymer Coatings Using Simulation and LOGSTA–LODECI–MUNRA Methods

by Figen Balo, Alptekin Ulutaş and Ilknur Ari

Coatings 2026, 16(7), 873; https://doi.org/10.3390/coatings16070873 - 21 Jul 2026

Cited by 2 | Viewed by 878

Abstract

An approach for the thermo-energy and environmental evaluation of polyhydroxyalkanoate (PHA)-based biopolymer coatings in green building envelopes is presented in this study. A boutique hotel designed for Antalya, Türkiye, was selected as a case study, and 117 multi-layer wall composites assemblies incorporating 13 [...] Read more.

An approach for the thermo-energy and environmental evaluation of polyhydroxyalkanoate (PHA)-based biopolymer coatings in green building envelopes is presented in this study. A boutique hotel designed for Antalya, Türkiye, was selected as a case study, and 117 multi-layer wall composites assemblies incorporating 13 different PHA-based coatings were evaluated. The thermal conductivity values were predicted by a crystallinity-dependent semi-empirical equation and used in dynamic building simulations with Integrated Environmental Solutions–Virtual Environment (IES-VE) to predict the annual energy use and CO₂ emissions. The performance of material was evaluated based on biodegradability, density, crystallinity, thermal stability, and mechanical properties by using the integrated LOGSTA–LODECI weighting and MUNRA ranking techniques. P3HB4HB showed the best overall material performance, in contrast to P3HB, which had the lowest energy requirement and emissions. The findings emphasize crystallinity as a key determinant for material and building energy performance. Full article

(This article belongs to the Special Issue Engineered Coatings for a Sustainable Future)

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19 pages, 49712 KB

Open AccessArticle

Numerical Prediction and Response-Surface Optimization of Narrow-Opening Micro-Pits Produced by Oblique Dual-Beam Femtosecond Laser Irradiation on Polyamide 6

by Hailong Zhang, Liujia Zhou, Chenbin Ma and Jian Lu

Coatings 2026, 16(7), 872; https://doi.org/10.3390/coatings16070872 - 21 Jul 2026

Viewed by 378

Abstract

Microstructures with narrow openings and enlarged internal volumes are highly desirable for durable superlubricating surfaces, as they enable increased lubricant storage and improved lubrication stability. However, conventional laser texturing typically produces tapered features with wider openings due to the intrinsic Gaussian energy distribution [...] Read more.

Microstructures with narrow openings and enlarged internal volumes are highly desirable for durable superlubricating surfaces, as they enable increased lubricant storage and improved lubrication stability. However, conventional laser texturing typically produces tapered features with wider openings due to the intrinsic Gaussian energy distribution of laser beams, limiting the achievable internal volume. To overcome this limitation, this study investigates an oblique dual-beam femtosecond laser ablation strategy for polyamide 6 (PA6) using a mechanism-informed optimization framework integrating COMSOL-based multiphysics simulations with response surface methodology (RSM). The effects of pulse energy, incident angle, and beam separation on micro-pit morphology are systematically analyzed. Pulse energy governs ablation intensity and feature scaling; increasing incident angle suppresses depth while promoting lateral expansion; and reduced beam separation enhances depth through local energy overlap. Quadratic regression models for pit depth, inner width, outer width, and ablated area are established via a central composite design and exhibit strong predictive capability. Multi-objective optimization identifies an effective processing window of 30–40 μJ pulse energy, 20–40° incident angle, and −12 to 12 μm beam separation, enabling uniform micro-pits with narrow openings and depths of 70–80 μm. Overall, this work provides a concise and predictive framework for oblique dual-beam laser texturing for predicting and guiding the future fabrication of narrow-opening, enlarged-interior microstructures. Full article

(This article belongs to the Special Issue Laser-Assisted Surface Modification and Coating Technologies)

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31 pages, 1300 KB

Open AccessReview

Thermal Spray Metallization of Polymers: A Review of Hybrid Polymeric–Metallic Coatings

by Muhammad Imran Khan, Anisa Riaz, Gul Badin, Luyang Xu, Xingyu Wang and Ying Huang

Coatings 2026, 16(7), 871; https://doi.org/10.3390/coatings16070871 - 21 Jul 2026

Viewed by 1027

Abstract

In recent years, the quest for advanced materials has intensified, driving the exploration of innovative coating systems to enhance material properties. Polymeric materials, renowned for their adaptability, have found extensive use across various industries. However, their inherent limitations in mechanical strength, wear resistance, [...] Read more.

In recent years, the quest for advanced materials has intensified, driving the exploration of innovative coating systems to enhance material properties. Polymeric materials, renowned for their adaptability, have found extensive use across various industries. However, their inherent limitations in mechanical strength, wear resistance, and thermal stability have prompted researchers to seek enhancement avenues. Hybrid polymeric–metallic coatings have emerged as a promising solution, employing thermal spray techniques to metalize polymeric substrates. This amalgamation utilizes the versatility of thermal spraying methods, ranging from cold spraying, flame spraying, arc spraying, to plasma spraying, to achieve robust adhesion between metal and polymer layers. These techniques yield durable composite structures, fortifying surfaces against corrosion and wear while enabling dimensional restoration. Cold spraying, in particular, stands out among thermal spray methods due to its effectiveness in metalizing various materials. This comprehensive review delves into recent advancements in hybrid polymeric–metallic coatings via thermal spray processes. Emphasis is placed on analyzing critical factors influencing coating properties, including various thermal spray parameters. Furthermore, the paper scrutinizes the challenges and future potentials inherent in thermal spray techniques, with a focused exploration of cold spray technology. Understanding these methodologies is pivotal for optimizing the design and durability of structural materials made of polymers or composites. Full article

(This article belongs to the Special Issue Thin Films: Materials, Fabrication Techniques, and Applications)

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5 pages, 163 KB

Open AccessEditorial

Ceramic and Glass Material Coatings: Advances in Raw Materials, Processing, Functional Performance, and Sustainability

by Manuel Miguel Jordán Vidal and María Belén Almendro-Candel

Coatings 2026, 16(7), 870; https://doi.org/10.3390/coatings16070870 - 20 Jul 2026

Viewed by 425

Abstract

Ceramic and glass material coatings have become essential components in numerous industrial sectors, including aerospace, energy production, transportation, construction, electronics, and advanced manufacturing [...] Full article

(This article belongs to the Special Issue Ceramic and Glass Material Coatings)

20 pages, 23705 KB

Open AccessArticle

Computational Study on the Na Storage Mechanism in Carbon Anodes Based on Bilayer Graphene Nanoribbons with Zigzag and Armchair Edges

by Sinan Li, Wei Dong, Shiyi Chen, Fudong Liu, Xiangran Meng and Jingming Zhao

Coatings 2026, 16(7), 869; https://doi.org/10.3390/coatings16070869 - 20 Jul 2026

Viewed by 401

Abstract

Hard carbon (HC) is one of the most promising anode materials for sodium-ion batteries (SIBs). Yet its sodiation mechanism—particularly the origin of the sloping and plateau regions in the voltage–capacity curve—remains debated. In this work, first-principles density functional theory (DFT) calculations are employed [...] Read more.

Hard carbon (HC) is one of the most promising anode materials for sodium-ion batteries (SIBs). Yet its sodiation mechanism—particularly the origin of the sloping and plateau regions in the voltage–capacity curve—remains debated. In this work, first-principles density functional theory (DFT) calculations are employed to systematically investigate the sodium storage mechanism at the edges and within the interlayer ultramicropores of bilayer graphene nanoribbons (BGNRs) with zigzag (BGNRs-Z) and armchair (BGNRs-A) terminations. A series of edge models, including hydrogenated, dehydrogenated (dangling bond), monovacancy (MV), and divacancy (DV) defects, were constructed to elucidate the effects of edge type and defect species on Na adsorption and intercalation. Our results demonstrate that Na ions preferentially adsorb at the edges rather than in the interior interlayer regions. The zigzag edge exhibits stronger binding affinity toward Na than the armchair edge. Progressive Na intercalation gradually opens the edge interlayer spacing. It reduces the interlayer angle toward a parallel configuration and accompanies a stacking transition from AB to AA at higher Na concentrations. Edge dangling bonds significantly enhance Na binding and drive the initial separation of edge carbon layers, whereas surface MV and DV defects contribute to Na adsorption at lower binding strengths. The calculated voltage–capacity relationships reveal that the first sloping region (>1.0 V) is primarily associated with Na adsorption at zigzag and defective edges, the second sloping region (0.1–1.0 V) can be rationalized by combined surface defect adsorption and interlayer intercalation, and the low-voltage plateau (<0.1 V) is thermodynamically linked to Na filling of narrow slit pores with optimized interlayer distances (~4.0 Å for zigzag and ~4.3–5.8 Å for armchair edges). These findings establish a direct structure–property correlation between carbon microstructure (edge type, defect architecture, and pore geometry) and the electrochemical voltage profile, offering atomic-level insights for the rational design of high-performance carbon-based anodes for SIBs. Full article

(This article belongs to the Section Surface Engineering for Energy Harvesting, Conversion, and Storage)

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32 pages, 7794 KB

Open AccessReview

Evolution of Functional Coatings on Metallic Substrates: Advanced Surface Solutions for Extreme Energy and Medical Applications

by Florentina Golgovici, Daniela Ionita, Radu Nartita, Mariana Prodana and Ioana Demetrescu

Coatings 2026, 16(7), 868; https://doi.org/10.3390/coatings16070868 - 20 Jul 2026

Viewed by 662

Abstract

Functional coatings have evolved from their early role as passive barriers against corrosion and wear into engineered interfaces that actively mediate the interaction between a bulk material and its environment. This review traces the evolution of coating technologies from traditional macroscopic protective layers [...] Read more.

Functional coatings have evolved from their early role as passive barriers against corrosion and wear into engineered interfaces that actively mediate the interaction between a bulk material and its environment. This review traces the evolution of coating technologies from traditional macroscopic protective layers to nanoscale and multifunctional systems, and finally to smart and stimuli-responsive architectures. Advanced deposition and surface modification techniques are examined, including atomic layer deposition, physical vapor deposition, electrochemical and sol–gel approaches. The discussion is structured around two complementary application domains: extreme energy environments, focusing on coatings developed for advanced nuclear systems, and modern medical implants, including bioactive and antimicrobial surfaces and drug-delivery interfaces. The review highlights that, despite the differences between reactor and biomedical environments, both sectors share a common set of design principles and challenges, including interfacial adhesion, mechanical durability, the dual role of nanostructuring, and the trade-off between architectural complexity and operational reliability. Long-term stability, scalability, and standardized validation remain key barriers to deployment, while data-driven design and the deliberate integration of multiple functions emerge as the principal directions for future development. Full article

(This article belongs to the Special Issue Smart and Functional Coatings Advancements in Synthesis, Characterization and Application)

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17 pages, 16869 KB

Open AccessArticle

Influence of Parameters in LDH Preparation on Its Morphology Structure and Corrosion Protection Property

by Jingjing Wang, Shuyou Luo, Kaifeng Chen, Yanhui Cao, Lingwei Ma and Dawei Zhang

Coatings 2026, 16(7), 867; https://doi.org/10.3390/coatings16070867 - 20 Jul 2026

Viewed by 380

Abstract

Layered double hydroxide (LDH) has been widely used in the field of corrosion protection. LDH nanofillers can act as multifunctional additives in coatings based on the physical barrier effect and anion exchange effect. However, the preparation of the typical co-precipitation method needs to [...] Read more.

Layered double hydroxide (LDH) has been widely used in the field of corrosion protection. LDH nanofillers can act as multifunctional additives in coatings based on the physical barrier effect and anion exchange effect. However, the preparation of the typical co-precipitation method needs to be simplified to realize large-scale industrialization. In this work, a wide range of synthesis parameters, including solution-mixing mode, reaction atmosphere, reaction pH control, titration rate and post-treatment on the obtained LDH, were systematically studied, and it was found that the one-step solution-mixing synthesis procedure and the adoption of N₂ atmosphere were able to alleviate the carbonate contamination to some degree. However, the one-step solution-mixing synthesis procedure has a negative influence on the formation of LDH, probably due to insufficient reaction, while the hydrothermal post-treatment is able to promote the continual growth of the LDH platelet and, thus, lead to an increase in crystallinity and particle size. Green inhibitor aspartates were used to modify LDH, and the electrochemical test results indicated that the adoption of N₂ atmosphere was able to clearly increase the corrosion protection ability of LDH, with an R_p value of 3.86 kΩ·cm² after immersion for 96 h in 0.1 mol/L NaCl, probably due to the intercalation of a relatively large amount of inhibitor anions since less carbonates were intercalated, followed by the LDH synthesized via co-precipitation without N₂ protection, pH control and hydrothermal post-treatment with an R_p value of 3.00 kΩ·cm². The LDH sample without inhibitor intercalation presented a corresponding R_p value of 2.45 kΩ·cm². Notably, the one-step solution-mixing method and a fast titration rate in co-precipitation would have a negative influence on the corrosion protection of LDH, probably due to insufficient reaction. This work could shed light on the simplification of LDH preparation, and it is able to provide a solid foundation and technical support for the wide promotion and application of LDH in anti-corrosion and other fields in the near future. Full article

(This article belongs to the Special Issue Coatings with Various Functionalities in Marine Environments)

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4 pages, 147 KB

Open AccessEditorial

Advances in Functional Bio-Coatings: Progress, Emerging Trends, and Future Perspectives

by Burak Dikici and Mosab Kaseem

Coatings 2026, 16(7), 866; https://doi.org/10.3390/coatings16070866 - 20 Jul 2026

Viewed by 416

Abstract

Functional bio-coatings have become one of the most dynamic research areas in biomaterials and surface engineering [...] Full article

(This article belongs to the Special Issue Advances in Functional Bio-Coatings)

11 pages, 3491 KB

Open AccessArticle

Confining CoFe Alloy Nanocubes Within N-Doped Carbon Shells via Pyrolysis of Phenolic Resin-Coated Etched Prussian Blue Analogs for Efficient Oxygen Evolution

by Yishan Jiang, Qichao Zhang, Shengyi Huang, Yaopeng Zhang, Ying Xu, Wanwan Zhang, Hu Zhou, Lizhi Lian and Yanxin Qiao

Coatings 2026, 16(7), 865; https://doi.org/10.3390/coatings16070865 - 20 Jul 2026

Viewed by 466

Abstract

Constructing core–shell structured carbon-coated alloy nanoparticles represents an effective strategy to enhance the electrocatalytic performance. In this work, CoFe-based Prussian blue analogs (PBAs) with hollow structures are firstly coated with phenolic resin via the in situ polymerization method. A subsequent carbonization treatment yields [...] Read more.

Constructing core–shell structured carbon-coated alloy nanoparticles represents an effective strategy to enhance the electrocatalytic performance. In this work, CoFe-based Prussian blue analogs (PBAs) with hollow structures are firstly coated with phenolic resin via the in situ polymerization method. A subsequent carbonization treatment yields N-doped carbon-encapsulated CoFe alloy nanocubes (denoted as CoFe-NC@C). The carbon shell suppresses the structural collapse and particle aggregation of CoFe nanocubes while enhancing the electrical conductivity, thereby facilitating fast reaction kinetics. Meanwhile, the etching-induced hierarchical pore structure increases the specific surface area with a Brunauer–Emmett–Teller (BET) value of 57 m² g⁻¹, which exposes more accessible active sites and facilitates mass transport. Owing to the synergistic effect between the two components, the CoFe-NC@C catalyst exhibits an outstanding oxygen evolution reaction (OER) performance in an alkaline electrolyte, achieving a low overpotential of 278 mV (vs. RHE) at a current density of 10 mA cm⁻² along with superb durability. This work demonstrates that the OER performance of PBA-derived alloys can be boosted through an integrated strategy of etching and carbon coating. Full article

(This article belongs to the Section Surface Engineering for Energy Harvesting, Conversion, and Storage)

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28 pages, 4377 KB

Open AccessReview

NAP-XPS Applications on Solid Oxide Cells Materials: A Short Review

by Davide Cademartori and Luca Vattuone

Coatings 2026, 16(7), 864; https://doi.org/10.3390/coatings16070864 - 20 Jul 2026

Viewed by 623

Abstract

Performance and durability of solid oxide cells are ruled by surface and interface phenomena occurring under operation. Electrode elementary reactions involve adsorption, charge transfer, surface diffusion and incorporation processes that are sensitive to the applied operating conditions and defect concentration. However, key degradation [...] Read more.

Performance and durability of solid oxide cells are ruled by surface and interface phenomena occurring under operation. Electrode elementary reactions involve adsorption, charge transfer, surface diffusion and incorporation processes that are sensitive to the applied operating conditions and defect concentration. However, key degradation mechanisms such as cation segregation, catalyst deactivation, phase transformations and microstructural evolution originate at/near the electrode surface. Consequently, understanding the surface chemistry of electrode materials is essential for the development of the next generation electrodes. In this frame, Near-Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS) has emerged as a powerful tool to probe chemically active surfaces under more realistic environments, thus correlating surface science and electrochemistry. This review covers the principles of NAP-XPS and its application to solid oxide cell materials, including ceria-based model electrodes, Ni-containing fuel electrodes, exsolved perovskites and mixed ionic-electronic conducting air electrodes. NAP-XPS demonstrated the ability to directly monitor the dynamic state of the electrode surface under controlled operating conditions. Common mechanistic insights and emerging trends are highlighted, together with potential limitations associated with current experimental configurations. Overall, combined NAP-XPS and electrochemical analyses appear to hold the potential for linking surface chemistry with electrode performance and degradation, thus supporting the rational design of the next-generation solid oxide cell materials. Full article

(This article belongs to the Special Issue Surface Engineering of Solid-State Electrochemical Systems for Energy Conversion and Storage)

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14 pages, 5572 KB

Open AccessArticle

Effect of Working Voltage on the Microstructure and Comprehensive Properties of Electro-Brush-Plated Nickel–Graphene Composite Coatings

by Zhongke Zhang, Haonan Wang, Wenhao Ma and Yingbo Ma

Coatings 2026, 16(7), 863; https://doi.org/10.3390/coatings16070863 - 19 Jul 2026

Viewed by 753

Abstract

To improve the surface service durability and heat-transfer performance of brass heat-dissipation components, Ni–graphene (Ni–Gr) composite coatings were prepared on brass substrates by electro-brush plating, and the effects of working voltage on the coating microstructure and overall performance were investigated. The coating thickness [...] Read more.

To improve the surface service durability and heat-transfer performance of brass heat-dissipation components, Ni–graphene (Ni–Gr) composite coatings were prepared on brass substrates by electro-brush plating, and the effects of working voltage on the coating microstructure and overall performance were investigated. The coating thickness ranged from 6.667 to 19.334 μm. The results show that the coating prepared at 7 V had a thickness of 8.524 μm, a dense microstructure, relatively uniform graphene dispersion, and the lowest Raman I_D/I_G ratio of 1.2146, thereby exhibiting the best overall performance. The microhardness of this coating reached 395 HV, which was approximately 190% and 127% higher than those of the brass substrate and pure Ni coating, respectively. Its corrosion current density in 3.5 wt.% NaCl solution decreased to 1.0143 × 10⁻⁵ A/cm², corresponding to a 90.4% reduction relative to the pure Ni coating. The room-temperature thermal conductivity of the coating/brass composite specimen reached 145 W/(m·K), which was 29.5% higher than that of the brass substrate. When the working voltage increased to 9–11 V, although the coatings became thicker, surface nodules coarsened, pores/pinholes increased, and graphene agglomeration intensified, leading to declines in mechanical properties, corrosion resistance, and thermal conductivity. These results demonstrate that an appropriate working voltage is beneficial for coordinating Ni nucleation/growth and graphene co-deposition, and is a key processing parameter for obtaining high-performance Ni–Gr composite coatings for brass heat-dissipation components. Full article

(This article belongs to the Special Issue Mechanical, Wear, and Functional Properties of Composite Coatings)

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18 pages, 8438 KB

Open AccessArticle

Phosphonic Acid-Derived Dual-Metal Passivation of Cu and Al for Corrosion-Resistant Wire-Bonded Interconnects

by Shinoj Sridharan Nair, Dinesh Kumar Kumaravel, Pavan Singh Ahluwalia, Khanh Tuyet Anh Tran, Duwage Anushka Sandaruwan Perera, Shyam Muralidharan Nair and Oliver Chyan

Coatings 2026, 16(7), 862; https://doi.org/10.3390/coatings16070862 - 18 Jul 2026

Viewed by 480

Abstract

Copper–aluminum (Cu-Al) wire-bonded devices are widely used in microelectronic packaging; however, corrosion at exposed Cu-Al bimetallic interfaces can lead to Al pad degradation, undercutting, and eventual ball-bond lift-off or open-circuit failure under humid, halide-contaminated conditions. This work presents a scalable post-wire-bond wet-chemical passivation [...] Read more.

Copper–aluminum (Cu-Al) wire-bonded devices are widely used in microelectronic packaging; however, corrosion at exposed Cu-Al bimetallic interfaces can lead to Al pad degradation, undercutting, and eventual ball-bond lift-off or open-circuit failure under humid, halide-contaminated conditions. This work presents a scalable post-wire-bond wet-chemical passivation process using octadecylphosphonic acid (ODPA) to simultaneously modify exposed Cu/Pd-coated Cu (PCC) and Al surfaces. The passivation process includes a hydroxylation pretreatment to generate reactive oxide/hydroxide surface sites, followed by ODPA treatment and solvent rinsing to remove weakly adsorbed species. Surface modification was evaluated using contact-angle measurements, reflection–absorption infrared spectroscopy (RAIRS), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). ODPA treatment increased the water contact angle on Cu and Al, confirming a substantial increase in surface hydrophobicity following coating formation. RAIRS identified ODPA-associated aliphatic C-H bands, AFM showed treatment-induced nanoscale surface changes, and XPS supported metal–oxygen–phosphorus interfacial bonding. Under aggressive 100 ppm chloride-ion immersion, ODPA passivation strongly suppressed corrosion-induced ball-bond lift-off across both device platforms. Lift-off decreased from 99.0% to 0.73% for Cu-Al devices and from 23.3% to 0.42% for PCC-Al devices. Collectively, these findings establish an effective, process-compatible post-wire-bond strategy for substantially protecting corrosion-susceptible interfaces and thereby improving the reliability of wire-bonded interconnects in halide-containing environments. Full article

(This article belongs to the Section Corrosion, Wear and Erosion)

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26 pages, 7332 KB

Open AccessReview

Advances in Surface Finishing of Wood Products: Toward Functionalization, Intelligence, and Sustainability

by Jingxuan Lu and Xinhao Feng

Coatings 2026, 16(7), 861; https://doi.org/10.3390/coatings16070861 - 18 Jul 2026

Viewed by 425

Abstract

This review systematically summarizes recent advances in the field of surface finishing for wood products, with a focus on three cutting-edge directions: functionalization, intelligence, and sustainability. The article first outlines the fundamental theories and the evolution and modernization of traditional surface-finishing techniques, then [...] Read more.

This review systematically summarizes recent advances in the field of surface finishing for wood products, with a focus on three cutting-edge directions: functionalization, intelligence, and sustainability. The article first outlines the fundamental theories and the evolution and modernization of traditional surface-finishing techniques, then delves into the construction mechanisms and performance characteristics of advanced functional surfaces such as superhydrophobic, self-cleaning, and smart-responsive coatings. Surface finishing of wood products is transitioning from conventional passive protection and aesthetic enhancement toward active functional empowerment and intelligent interaction. Functionalization, intelligence, and sustainability have become mainstream trends in technological development, supported by the deep integration of materials science, digital technologies, and design disciplines. Finally, the paper identifies current research challenges and prospects for key future research directions, aiming to provide a systematic knowledge framework and developmental guidance for academic studies in wood-product surface finishing. Full article

(This article belongs to the Section Composite Coatings)

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24 pages, 4055 KB

Open AccessReview

Phase Change Materials in Lime-Based Mortars for the Energy Efficiency of Historic Buildings: State-of-the-Art and Prospects

by Antonella Sarcinella and Mariaenrica Frigione

Coatings 2026, 16(7), 860; https://doi.org/10.3390/coatings16070860 - 18 Jul 2026

Viewed by 365

Abstract

Historic buildings represent a substantial share of the European building stock. However, their energy retrofit is heavily restricted by conservation principles that often exclude conventional insulation systems. In this context, phase change materials (PCMs) incorporated into lime-based mortars have emerged as a potentially [...] Read more.

Historic buildings represent a substantial share of the European building stock. However, their energy retrofit is heavily restricted by conservation principles that often exclude conventional insulation systems. In this context, phase change materials (PCMs) incorporated into lime-based mortars have emerged as a potentially compatible solution, combining latent heat storage capacity with the compatibility traditionally associated with aerial lime, the binder of reference in conservation practice. In some cases, natural hydraulic lime and hydrated lime are also used in heritage conservation applications. The aim of this study, therefore, is to provide a systematic review of peer-reviewed articles published between 2010 and 2026 that illustrate the use of PCM-containing lime mortars applied in historic buildings. The analysis examines PCM types, incorporation methods, thermal and mechanical behavior, durability, and compatibility with conservation requirements. The reviewed studies demonstrate that the incorporation of PCM generally reduces internal thermal fluctuations in buildings along with capillary water absorption. Durability investigations indicate improved resistance to freeze–thaw cycles and salt crystallization of mortars containing such PCMs. However, durability was investigated in less than 20% of the studies reviewed. Lime mortars show a consistent reduction in compressive strength as the PCM content increases; on the other hand, hydrated lime mortars can also offer increases in strength. Although the reviewed studies focused on applications in historic buildings, the reversibility of the intervention and its compatibility with historic substrates was not assessed according to the standards required for the conservation of cultural heritage. This gap represents the main limitation of the research conducted. Full article

(This article belongs to the Section Cultural Heritage and Protective Coatings)

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23 pages, 34733 KB

Open AccessArticle

Enhanced Anti-Icing and Anti-Corrosion Hydrophobic Coating: Based on Photothermal Complementarity and Multi-Scale Synergy

by Wansong Bai, Minghui Zhang, Feng Lv, Junyu Chen, Pengcheng Sun, Xuesong Bai, Xu Zhang, Hang Zhang, Guowei Wang, Shuguang Zhang, Guibin Shan and Dan Song

Coatings 2026, 16(7), 859; https://doi.org/10.3390/coatings16070859 - 18 Jul 2026

Viewed by 424

Abstract

Ice formation and corrosion pose dual threats to critical infrastructure, such as power systems. Developing composite coatings that integrate efficient photothermal de-icing with long-term corrosion protection is of great value. In this study, a ternary synergistic hydrophobic coating was constructed utilizing multi-component fillers [...] Read more.

Ice formation and corrosion pose dual threats to critical infrastructure, such as power systems. Developing composite coatings that integrate efficient photothermal de-icing with long-term corrosion protection is of great value. In this study, a ternary synergistic hydrophobic coating was constructed utilizing multi-component fillers with complementary light absorption properties and multi-scale structures. The surface morphology, microstructure, optical absorption, wettability, ice delay behavior, photothermal de-icing performance, and corrosion resistance were systematically characterized using SEM, UV-Vis-NIR, AFM, contact angle goniometry, infrared thermography, and electrochemical analysis. The results demonstrate that the multi-component fillers construct unique multi-scale microstructures within the PDMS matrix. This architecture not only enhances surface hydrophobicity and delays ice nucleation but also delivers outstanding photothermal de-icing performance owing to its excellent broadband light absorption capability. Meanwhile, electrochemical tests reveal that the coating exhibits superior corrosion protection, reducing the corrosion current density by nearly four orders of magnitude compared to the unmodified substrate. This enhancement mechanism is primarily attributed to the ternary synergy among the fillers, which integrates complementary photothermal conversion, surface microstructuring, and corrosion barrier effects. This work provides a crucial strategy for developing novel coatings that integrate both anti-icing and anti-corrosion functionalities. Full article

(This article belongs to the Special Issue Advanced Metallic Materials: Corrosion Protection and Surface Engineering)

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15 pages, 3648 KB

Open AccessArticle

Polarization-Encoded Switchable Structured Light Generator Based on All-Dielectric Holographic Metasurfaces

by Xi Xu, Zibo Lu, Haoze Pan, Shun Zhou, Changda Zhou, Qi Xu, Reiu Takeda and Qi Zhang

Coatings 2026, 16(7), 858; https://doi.org/10.3390/coatings16070858 - 17 Jul 2026

Viewed by 499

Abstract

Metasurfaces, as emerging functional optical coatings, enable precise wavefront manipulation at the subwavelength scale. In this work, we propose a polarization-encoded switchable structured light generator based on a single-layer holographic metasurface composed of silicon nanopillars. By combining Fresnel holography technology and the Pancharatnam–Berry [...] Read more.

Metasurfaces, as emerging functional optical coatings, enable precise wavefront manipulation at the subwavelength scale. In this work, we propose a polarization-encoded switchable structured light generator based on a single-layer holographic metasurface composed of silicon nanopillars. By combining Fresnel holography technology and the Pancharatnam–Berry phase modulation principle, two sets of holographic phase distributions for perfect vortex beams corresponding to orthogonal circularly polarized states are superimposed onto a single metasurface. The optimized nanopillar achieves a transmittance of approximately 85% and a polarization conversion efficiency of around 98% at the wavelength of 632.8 nm. By simply adjusting the incident polarization state, the metasurface generates a perfect vortex beam under right-handed circularly polarized light illumination and a cylindrical vector beam under horizontal linearly polarized light illumination, enabling on-demand switching between the two structured light modes. Furthermore, we design and validate a spatially multiplexed perfect vortex beam generator, in which the radius, topological charge, and focal plane position of each channel can be independently controlled. This flexible thin-film metasurface platform offers a promising route toward compact, multifunctional photonic devices for advanced optical integration. Full article

(This article belongs to the Special Issue Bound States in the Continuum in Metamaterials and Metasurfaces)

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23 pages, 6436 KB

Open AccessArticle

Grain Refinement and Property Trade-Offs in Laser Cladded Ni60-WC Coating Induced by 2% ZrO₂ Addition

by Xianglin Wu, Jingquan Wu and Dianlong Chen

Coatings 2026, 16(7), 857; https://doi.org/10.3390/coatings16070857 - 17 Jul 2026

Cited by 1 | Viewed by 325

Abstract

To improve the surface properties of Q235 steel, two types of composite coatings were prepared using laser cladding technology: a 25% WC + 75% Ni60 coating (Group NO) and a 25% WC + 73% Ni60 coating with 2% ZrO₂ added (Group 2). [...] Read more.

To improve the surface properties of Q235 steel, two types of composite coatings were prepared using laser cladding technology: a 25% WC + 75% Ni60 coating (Group NO) and a 25% WC + 73% Ni60 coating with 2% ZrO₂ added (Group 2). Through XRD, SEM, microhardness testing, friction and wear testing, and electrochemical testing, the effects of ZrO₂ on the phase composition, microstructure, mechanical properties, and corrosion resistance of the coatings were systematically investigated. The results indicate that upon the addition of ZrO₂, Zr atoms solid-solve into the γ-Ni lattice, causing the grain size to refine from 17.36 nm to 10.84 nm, and the carbides to transform from coarse cuboidal particles (average 4.00 μm) into fine, irregularly shaped, dispersed particles (average 2.93 μm); the average hardness of the coating decreased from 901.51 HV0.2 to 576.20 HV0.2, but the uniformity of the hardness distribution improved significantly (standard deviation decreased from 142.75 to 29.74); the coefficient of friction increased from 0.71 to 0.85, and the wear volume increased from 0.04 mm³ to 0.38 mm³, indicating a decline in wear resistance; in a 3.5% NaCl solution, the corrosion potential shifted positively by 38 mV, and the corrosion rate decreased from 0.7234 mm·a⁻¹ to 0.7071 mm·a⁻¹, indicating a slight improvement in corrosion resistance. In summary, the addition of 2% ZrO₂ achieves grain refinement, carbide homogenization, and improved corrosion resistance, but reduces hardness and wear resistance. It is suitable for operating conditions where corrosion resistance and microstructural uniformity are the primary considerations. Full article

(This article belongs to the Special Issue Recent Development in Post-Processing for Additive Manufacturing (Second Edition))

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23 pages, 4848 KB

Open AccessArticle

Fabrication of Paraffin/Sepiolite Composite Phase Change Coatings for Building Thermal Insulation

by Lixin Zhang, Xinjing Zheng, Haizhen Li, Tianliang Wang, Shaowei Bai, Shengfei Guo, Longtao Wang and Gang Yu

Coatings 2026, 16(7), 856; https://doi.org/10.3390/coatings16070856 - 17 Jul 2026

Viewed by 408

Abstract

To develop energy-efficient building coatings with enhanced thermal energy storage performance, paraffin/sepiolite composite phase change coatings were prepared using ultrasonic-assisted acid-activated sepiolite as a supporting matrix. The effects of acid treatment duration on the structural properties of sepiolite and the performance of the [...] Read more.

To develop energy-efficient building coatings with enhanced thermal energy storage performance, paraffin/sepiolite composite phase change coatings were prepared using ultrasonic-assisted acid-activated sepiolite as a supporting matrix. The effects of acid treatment duration on the structural properties of sepiolite and the performance of the resulting coatings were systematically investigated. The results showed that acid activation for 1 h produced the optimal pore structure, yielding a maximum internal specific surface area of 125.881 m² g⁻¹. Longer treatment durations (>2 h) caused structural degradation and possible deterioration of pore structure. The paraffin/sepiolite composite phase change material prepared with JK-1 h exhibited a latent heat of 77.29 J g⁻¹, outperforming that prepared with JK-2 h. Increasing the paraffin and CPCM contents enhanced the thermal storage capacity of the coatings; however, excessive CPCM loading deteriorated film integrity, resulting in cracking, reduced adhesion, and decreased hydrophobicity. Among all formulations, sample S3 demonstrated the best overall performance, with a latent heat of 33.51 J g⁻¹, a pull-off strength of 5.9 MPa, and a water contact angle of 102.53°. Thermal cycling tests further confirmed its excellent thermal reliability and reusability. These findings indicate that paraffin/sepiolite composite phase change coatings have considerable potential for reducing building energy consumption and improving indoor thermal regulation. Full article

(This article belongs to the Section Architectural and Infrastructure Coatings)

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17 pages, 6179 KB

Open AccessArticle

Research on the Performance of ZnO Piezoelectric Film Ultrasonic Transducers and Its Application in the Detection of Preload of Hydroelectric Bolts

by Xuechao Jing, Wenbo Li, Ameng Xie, Yanghui Jiang and Jun Zhang

Coatings 2026, 16(7), 855; https://doi.org/10.3390/coatings16070855 - 17 Jul 2026

Viewed by 428

Abstract

In this study, ZnO thin-film ultrasonic transducers were directly fabricated by reactive radio-frequency magnetron sputtering for bolt preload detection. The effects of deposition pressure and Ar/O₂ ratio on the morphology, crystal structure, piezoelectric response, and ultrasonic performance of ZnO films were investigated. [...] Read more.

In this study, ZnO thin-film ultrasonic transducers were directly fabricated by reactive radio-frequency magnetron sputtering for bolt preload detection. The effects of deposition pressure and Ar/O₂ ratio on the morphology, crystal structure, piezoelectric response, and ultrasonic performance of ZnO films were investigated. The ZnO film deposited at 2.0 Pa with an Ar/O₂ ratio of 3:1 exhibited strong c-axis preferred orientation and generated stable high-frequency longitudinal ultrasonic waves with a center frequency above 50 MHz. After being deposited on the bolt surface, the optimized transducer showed a strong linear relationship between ultrasonic time-of-flight and axial load, with an R² value greater than 99.99% and an average measurement error below 1% within the preload range. Field monitoring at a hydropower station further showed that the preload variation of randomly selected bolts was negatively correlated with temperature, mainly due to the thermal deformation mismatch between 35CrMo bolts and Q235-B flanges. The maximum preload variation was approximately 40 kN, accounting for about 6.7% of the specified preload of 600 kN, while no abnormal preload loss was observed. These results demonstrate that ZnO thin-film ultrasonic transducers provide a reliable and accurate approach for hydraulic bolt preload measurement and in-service monitoring, with better applicability than conventional torque-based methods. Full article

(This article belongs to the Section Thin Films)

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21 pages, 5744 KB

Open AccessArticle

A Lightweight Transformer with Corrosion Gating and Physical Embeddings for Pipeline Corrosion Growth Prediction

by Fangchao Kang, Zeguang Zhang, Hang Zhang, Guan Chen, Shuqian Shen, Gaoshen Cai, Xiaoqing Lu, Wenkai Chen and Maodong Li

Coatings 2026, 16(7), 854; https://doi.org/10.3390/coatings16070854 - 17 Jul 2026

Viewed by 395

Abstract

Pipeline corrosion critically threatens the safe operation of chemical industrial park pipeline networks, making accurate corrosion growth prediction essential for preventing catastrophic failures. Mechanistic models assume steady states, which conflict with in-service corrosion dynamics; data-driven approaches, however, presume complete datasets but frequently face [...] Read more.

Pipeline corrosion critically threatens the safe operation of chemical industrial park pipeline networks, making accurate corrosion growth prediction essential for preventing catastrophic failures. Mechanistic models assume steady states, which conflict with in-service corrosion dynamics; data-driven approaches, however, presume complete datasets but frequently face missing parameters due to sensor failures and limited samples from costly inspections, increasing the risk of noise and overfitting. In this paper, the TinyTransCorrosion model was proposed, which is a lightweight Transformer-based corrosion growth prediction model specifically designed for small-sample scenarios. A cross-validation residual analysis is employed for data cleaning, while five physical embedding features are constructed to encode domain knowledge and compensate for missing parameters. A compact Transformer encoder containing only 6433 parameters was adopted, and a corrosion gating mechanism along with a classification (CLS) token was introduced to achieve efficient feature interaction. Evaluated on a real-world pipeline inspection dataset with 215 records, TinyTransCorrosion attains an R² of 0.6411 and an MAE of 0.1608 mm, outperforming nine conventional baseline models, including Mean predictor, Linear Regression, Ridge, SVR-RBF, Random Forest, XGBoost, LSTM, MLP, and CNN. While these results are limited to a single-site dataset and require external validation on independent multi-source data, the proposed lightweight physics-guided architecture demonstrates promising predictive capability for small-sample pipeline corrosion assessment, with model error approaching the metrological limit imposed by field ultrasonic gauge accuracy. It provides an acceptable pathway for prioritizing inspection intervals and optimizing maintenance scheduling in resource-constrained industrial settings. Full article

(This article belongs to the Special Issue Recent Progress in Laser Additive Manufacturing of Alloys: Methods, Microstructures and Properties)

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15 pages, 15964 KB

Open AccessArticle

Comparative Study on Microstructures and Wear Properties of Laser-Clad AlCoCrFeNi High-Entropy Alloy Coating and TiC/AlCoCrFeNi Composite Coating

by Lianmeng Wang, Jianke Luo, Jiang Wang, Ying Xu, Hui Dong and Yongsheng Zhu

Coatings 2026, 16(7), 853; https://doi.org/10.3390/coatings16070853 - 17 Jul 2026

Viewed by 490

Abstract

Steel components in thermal power plants are vulnerable to severe wear and wall thinning induced by the high-velocity impact of pulverized coal, which significantly compromises their service life and structural integrity. To address this issue, a TiC-reinforced AlCoCrFeNi high-entropy alloy (HEA) composite coating [...] Read more.

Steel components in thermal power plants are vulnerable to severe wear and wall thinning induced by the high-velocity impact of pulverized coal, which significantly compromises their service life and structural integrity. To address this issue, a TiC-reinforced AlCoCrFeNi high-entropy alloy (HEA) composite coating was fabricated via laser cladding, aiming to substantially enhance the wear resistance of these critical components. The phase composition, microstructure, microhardness and tribological behaviors of the coatings were systematically investigated by XRD, SEM, EDS and dry sliding wear tests. Results show that both coatings possess dense microstructures and reliable metallurgical bonding with the substrate. The AlCoCrFeNi coating consists of a single BCC solid solution phase, while the TiC/AlCoCrFeNi composite coating contains a BCC phase and a TiC ceramic phase without brittle intermetallic compounds. The average microhardness of the TiC/AlCoCrFeNi composite coating was measured to be 823 HV_0.3, which is 85.66% greater than that of the AlCoCrFeNi coating (443 HV_0.3). Under identical wear test conditions, the AlCoCrFeNi coating exhibits a mass loss of 31.4 mg and a volumetric wear rate of 24 × 10⁻³ mm³/min, whereas the TiC/AlCoCrFeNi composite coating exhibits a mass loss of 15.6 mg and a wear rate of 13 × 10⁻³ mm³/min, corresponding to reductions of approximately 50.32% and 45.83%, respectively. The wear mechanism of the AlCoCrFeNi coating is dominated by severe abrasive wear coupled with adhesive wear, while the addition of TiC converts the wear mechanism into mild abrasive wear and oxidative wear. The incorporation of TiC particles effectively enhances the microhardness and reduces the mass loss, thereby contributing to a marked improvement in the wear properties of the laser-clad AlCoCrFeNi coating. This research provides experimental data and theoretical support for the engineering application of TiC/AlCoCrFeNi composite coatings on wear-resistant components in thermal power units. Full article

(This article belongs to the Special Issue Advanced Thin Films of High-Entropy Alloys)

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