Coatings

13 pages, 2897 KB

Open AccessArticle

Enhancing the Mechanical Robustness of Aerosol-Based Brittle Pt/C Electrodes Through Thermal Annealing

by Nathan Heo, Won-Yong Jeong, Ji Hun Kim and Jae-Bum Pyo

Coatings 2025, 15(11), 1331; https://doi.org/10.3390/coatings15111331 (registering DOI) - 15 Nov 2025

Nanoporous Pt/C electrodes fabricated via aerosol coating offer excellent reactant delivery and electrochemical activity owing to their high porosity. However, the practical application prospects of such electrodes are limited by their poor mechanical properties. Herein, we quantitatively analyze the effects of thermal annealing [...] Read more.

Nanoporous Pt/C electrodes fabricated via aerosol coating offer excellent reactant delivery and electrochemical activity owing to their high porosity. However, the practical application prospects of such electrodes are limited by their poor mechanical properties. Herein, we quantitatively analyze the effects of thermal annealing (at 110, 150, 190, and 230 °C) on the mechanical stability and electrical properties of aerosol-based Pt/C electrodes. Post-annealing at an optimal temperature of 190 °C improved the tensile strength by 65.3%, increased their elongation from 0.82% to 1.78%, and decreased the electrical resistance while maintaining the secondary pore structure. Analyses of the electrode’s surface roughness, pore structure, and contact angle indicate that thermal reconstruction of the ionomer is crucial for stabilizing the electrode structure and controlling its surface properties. Finite element simulations using experimentally measured single-electrode properties enabled accurate prediction of the mechanical behavior of the membrane electrode assembly. These results provide design guidelines for balancing the process efficiency with the mechanical stability of aerosol-based Pt/C electrodes and can be used to improve their application prospects in aerosol-based fuel cell catalyst layers. Full article

(This article belongs to the Special Issue Advanced Functional Nanostructured Films and Coatings for Energy Applications, 2nd Edition)

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35 pages, 8276 KB

Open AccessArticle

High-Energy Supercapacitor Constructed by Cerium-Doped Iron Tungstate Cathode Materials with Oxygen Vacancies and Hydrophilic Carbon Nanotube Anode

by Liyuan Shan and Lei Xiong

Coatings 2025, 15(11), 1330; https://doi.org/10.3390/coatings15111330 - 14 Nov 2025

Abstract

To address the worsening energy crisis from rapid fossil fuel consumption, this study synthesized Ce-FeWO₄ composites and hydrophilic carbon nanotubes. XRD and other characterizations showed all intermediates had rough, porous nanosheet morphology; Ce-doping formed disordered porous structure in FeWO₄, increasing [...] Read more.

To address the worsening energy crisis from rapid fossil fuel consumption, this study synthesized Ce-FeWO₄ composites and hydrophilic carbon nanotubes. XRD and other characterizations showed all intermediates had rough, porous nanosheet morphology; Ce-doping formed disordered porous structure in FeWO₄, increasing its specific surface area. Three-electrode tests confirmed optimal parameters: 0.5% Ce-doping and 12 h growth. Ce-FeWO₄ exhibited a specific capacity of 1875 ± 28 F/g at 1 A/g (based on five parallel samples), and retained 1807 F/g after 3000 cycles (exceeding previous studies) with excellent stability. The Ce-FeWO₄//CNTs asymmetric supercapacitor achieved 152 F/g specific capacity, 81.4 Wh/g energy density, and 768 W/kg power density. The simple, efficient, eco-friendly preparation process and the material’s high capacitance and stability offer broad application prospects in the electrode field. Full article

(This article belongs to the Special Issue High-Performance Dielectric Ceramic Films and Coatings for Energy Storage Capacitors)

22 pages, 7928 KB

Open AccessArticle

Oxidation-Resistant Ni-AlSi12 Composite Coating with Strong Adhesion on Ti-6Al-4V Alloy Substrate via Mechanical Alloying and Subsequent Laser Cladding

by Huanjian Xie, Luyan Xu, Jian Jiang, Haoge Shou, Hongzhang Hao and Ruizhi Feng

Coatings 2025, 15(11), 1329; https://doi.org/10.3390/coatings15111329 - 14 Nov 2025

Abstract

Two Ni-AlSi12 coatings were prepared using mechanical alloying (MA) and mechanical alloying followed by laser cladding (LC), respectively. Phase composition and microstructure variations caused by powder weight ratio and laser-specific energy were thoroughly analyzed in this study. Mechanical properties and oxidation behavior are [...] Read more.

Two Ni-AlSi12 coatings were prepared using mechanical alloying (MA) and mechanical alloying followed by laser cladding (LC), respectively. Phase composition and microstructure variations caused by powder weight ratio and laser-specific energy were thoroughly analyzed in this study. Mechanical properties and oxidation behavior are markedly improved by subsequent laser cladding. The MA-LC coating, characterized by high densification and crack-free properties, presents a homogeneous microstructure with refined features. Microhardness testing reveals a marked superiority of the MA-LC coating over the conventional MA coating. The nano-hardness of MA-LC coating is 9.79 GPa, exhibiting that it is 6.84 times the nano-hardness of the MA sample. Owing to metallurgical bonding, the MA-LC coating possesses excellent scratch bonding performance. The MA-LC coating shows favorable oxidation behavior, due to the following three reasons: Firstly, oxygen diffusion can be effectively blocked by the compact Al₂O₃ oxide layer developed on the MA-LC coating surface, which reduces the oxidation velocity. Secondly, the coating’s mean grain dimensions demonstrate an increasing tendency after oxidation, which reduces the grain boundary serving as the oxygen diffusion channel. This enhancement significantly improves the coating’s oxidation resistance. Thirdly, analysis of the coating’s respective kernel average misorientation (KAM) map revealed a significant release of internal stress following 100 h oxidation, which can improve the coating’s resistance to spallation. Full article

(This article belongs to the Special Issue Advances in Surface Welding Techniques for Metallic Materials)

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14 pages, 1661 KB

Open AccessArticle

On the Hydrophobicity, Superhydrophobicity and Icephobicity of Etched Aluminum Surfaces

by Marcella Balordi, Andrea Cammi, Alessandro Casali, Francesco Pini and Giorgio Santucci de Magistris

Coatings 2025, 15(11), 1328; https://doi.org/10.3390/coatings15111328 - 14 Nov 2025

Abstract

Several hydrophobic and superhydrophobic aluminum surfaces were prepared with a three-step process that includes chemical etching, a treatment in hot water and a further coating with fluoroalkysiloxane (FAS). By varying the concentration of the etchant, the immersion time in the etchant and the [...] Read more.

Several hydrophobic and superhydrophobic aluminum surfaces were prepared with a three-step process that includes chemical etching, a treatment in hot water and a further coating with fluoroalkysiloxane (FAS). By varying the concentration of the etchant, the immersion time in the etchant and the boiling time, surfaces characterized by different roughness were obtained, with a wettability ranging from hydrophobic to superhydrophobic values. The icephobic properties were tested and the results reveal important differences among the samples, related to the roughness of the surface and the etching and boiling treatment processes. Full article

(This article belongs to the Special Issue Superhydrophobic Surfaces and Coatings)

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20 pages, 3395 KB

Open AccessArticle

Can Satureja montana Essential Oil Promote Edible Films Based on Plum Oil Cake into Antimicrobial and Antioxidant Food Packaging?

by Jovana Pantić, Danijela Šuput, Sunčica Kocić-Tanackov, Sandra Bulut, Ivan Ristić, Biljana Lončar, Nevena Hromiš and Senka Popović

Coatings 2025, 15(11), 1327; https://doi.org/10.3390/coatings15111327 - 13 Nov 2025

Abstract

This study adheres to the principles of the circular economy by valorising fruit processing waste—specifically, the oil cake remaining after the cold pressing of plum seeds—for the production of new biopolymer packaging material. This study investigates the effects of incorporating Satureja montana essential [...] Read more.

This study adheres to the principles of the circular economy by valorising fruit processing waste—specifically, the oil cake remaining after the cold pressing of plum seeds—for the production of new biopolymer packaging material. This study investigates the effects of incorporating Satureja montana essential oil (SMeo) on the properties of plum oil cake (POC)-based biofilms for potential food packaging applications. The mechanical, physico-chemical, barrier, structural, thermal, and biological properties of the POC-based film were investigated. The results showed that the addition of SMeo had the greatest impact on improving the water vapor barrier permeability (up to 48%). Antimicrobial analyses showed outstanding results against bacteria, yeasts, and molds, with the most pronounced inhibition observed for A. ochraceus and S. aureus. On the other hand, structural analysis confirmed that the 3% SMeo sample underwent the greatest changes, as indicated by the appearance of new bonds originating from oil–biopolymer interactions. This observation was further supported by thermal analysis, which showed that films containing SMeo degraded more rapidly than the control in a dose-dependent manner. The reduction in tensile strength values (up to 35%) suggests that SMeo-loaded POC films are more suitable for use as coatings rather than standalone packaging materials. Full article

(This article belongs to the Special Issue Advances in Food Technology: Bioactive Films and Coatings for Food Packaging)

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15 pages, 16984 KB

Open AccessArticle

Unveiling the Regulatory Mechanism of Zr Content on the Microstructure, Mechanical Properties and Stability of Cu-Zr Nanocrystalline Alloy Films

by Ying Wang, Yifeng Jiang, Shuaishuai Yan, Hailong Shang, Xiaoben Qi and Ning Zhong

Coatings 2025, 15(11), 1326; https://doi.org/10.3390/coatings15111326 - 13 Nov 2025

Abstract

A series of Cu-Zr nanocrystalline alloy films with varying Zr contents were fabricated via magnetron co-sputtering technology. The effect of Zr content on the microstructure and mechanical properties of the alloy films was investigated, and the strengthening mechanism was revealed. Furthermore, the stability [...] Read more.

A series of Cu-Zr nanocrystalline alloy films with varying Zr contents were fabricated via magnetron co-sputtering technology. The effect of Zr content on the microstructure and mechanical properties of the alloy films was investigated, and the strengthening mechanism was revealed. Furthermore, the stability of nanocrystalline alloy films was studied through annealing experiments at different temperatures. The results show that part of the added Zr atoms are dissolved in the Cu lattice to form a solid solution structure of Zr in Cu, while the other part segregates at the grain boundaries. No second-phase compounds or simple substances are formed in the alloy films. The addition of Zr significantly refines the grain size of the alloy films. The hardness of the films exhibits a gradual increase with the elevation of Zr content. The results indicate that there are three main strengthening factors for the alloy films: grain refinement strengthening effect (

∆ H_{G B}

, accounting for exceeding 70%), solid solution strengthening effect (

∆ H_{S S}

, accounting for approximately 20%) and nanocrystalline solute atom pinning strengthening effect (

∆ H_{N C, S S}

, accounting for less than 10%). Among them, the strengthening effect of grain refinement assumes a predominant role. Regarding stability, Zr atoms segregate at the grain boundaries of the alloy films. The segregation becomes more significant as the annealing temperature rises. This segregation of Zr atoms at the grain boundaries can exert a pinning effect on the grain boundaries and impede their migration, thus significantly improving the structural stability of the alloy films. Full article

(This article belongs to the Special Issue Heterogeneous Nanostructured Coatings: Design, Preparation, and Application)

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27 pages, 3139 KB

Open AccessReview

Intelligent Sensing and Responsive Separators for Lithium Batteries Using Functional Materials and Coatings for Safety Enhancement

by Junbing Tang, Zhiyan Wang, Yongzheng Zhang, Duan Bin and Hongbin Lu

Coatings 2025, 15(11), 1325; https://doi.org/10.3390/coatings15111325 - 13 Nov 2025

Abstract

With the increasing demand for high-energy-density lithium batteries, the role of separators has expanded significantly beyond conventional ion conduction and physical isolation. By integrating sensors and introducing functional coatings, separators have gained the ability to monitor internal states in real time and achieve [...] Read more.

With the increasing demand for high-energy-density lithium batteries, the role of separators has expanded significantly beyond conventional ion conduction and physical isolation. By integrating sensors and introducing functional coatings, separators have gained the ability to monitor internal states in real time and achieve adaptive regulation. This paper systematically reviews the latest research progress on separators modified with functional materials and coatings to achieve information sensing, intelligent response, and multifunctional integration. Notably, an electrochemical sensor based on MXene/MWCNTs-COOH/MOF-808 has been developed for rapid chemical detection; a fully printed ultra-thin flexible multifunctional sensor array has enabled multi-parameter synchronous monitoring; an ion-selective MOF-808-EDTA separator has induced uniform lithium-ion flux; and a PVDF-HFP/LLZTO/PVDF-HFP trilayer separator has maintained structural integrity at 300 °C. These innovative achievements fully demonstrate the enormous potential of intelligent separators in monitoring internal battery states, inhibiting dendrite growth, preventing thermal runaway, and significantly enhancing battery safety, cycle life, and energy density. This points to a transformative development path for the next generation of batteries with higher safety and intelligence. Full article

(This article belongs to the Special Issue Recent Progress on Functional Films and Surface Science)

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11 pages, 1101 KB

Open AccessArticle

Optimization of Coatings Materials of Cds/Snse Solar Cell Using Snte as Hole Transport Layer: An Overview of Different Recombination Mechanisms

by Fernando J. Sánchez-Rodríguez, José G. Ojeda-Inzunza, Alexis Carrillo-Osuna, Andres Barraza-Valencia, Levy N. Inzunza-Camacho, Jose P. Ruelas-Leyva, Isaac Montoya de los Santos, Jesus J. Molina-Duarte, Salvador Meza-Aguilar, Francisco Ramos-Brito and Maykel Courel

Coatings 2025, 15(11), 1324; https://doi.org/10.3390/coatings15111324 - 12 Nov 2025

Abstract

In this work the authors analyze a CdS/SnSe solar cell using a SnTe as a hole transport layer. We analyzed the impact of the recombination mechanisms namely radiative, and Shockley–Read–Hall in the bulk and at the interfaces using SCAPS-1D software and the impact [...] Read more.

In this work the authors analyze a CdS/SnSe solar cell using a SnTe as a hole transport layer. We analyzed the impact of the recombination mechanisms namely radiative, and Shockley–Read–Hall in the bulk and at the interfaces using SCAPS-1D software and the impact of SnSe and CdS layer thickness. Additionally, the effect of concentration of acceptors and bulk defects in SnTe and SnSe on the performance were studied. The conditions that optimize device performance are presented. The results of the present study suggest that using a SnTe hole transport layer can result in an efficiency promotion from 0.7% to 24.48%. Full article

(This article belongs to the Special Issue Coatings Materials for Photovoltaic)

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14 pages, 3122 KB

Open AccessArticle

Environmentally Friendly Silk Fibroin/Polyethyleneimine High-Performance Triboelectric Nanogenerator for Energy Harvesting and Self-Powered Sensing

by Ziyi Guo, Xinrong Xu, Yue Shen, Menglong Wang, Youzhuo Zhai, Haiyan Zheng and Jiqiang Cao

Coatings 2025, 15(11), 1323; https://doi.org/10.3390/coatings15111323 - 12 Nov 2025

Abstract

Due to the large emissions of greenhouse gases from the burning of fossil fuels and people’s demand for green materials and energy, the development of environmentally friendly triboelectric nanogenerators (TENGs) is becoming increasingly significant. Silk fibroin (SF) is considered an ideal biopolymer candidate [...] Read more.

Due to the large emissions of greenhouse gases from the burning of fossil fuels and people’s demand for green materials and energy, the development of environmentally friendly triboelectric nanogenerators (TENGs) is becoming increasingly significant. Silk fibroin (SF) is considered an ideal biopolymer candidate for fabricating green TENGs due to its biodegradability and renewability. However, its intrinsic brittleness and relatively weak triboelectric performance severely limit its practical applications. In this study, SF was physically blended with poly(ethylenimine) (PEI), a polymer rich in amino groups, to fabricate SF/PEI composite films. The resulting films were employed as tribopositive layers and paired with a poly(tetrafluoroethylene) (PTFE) tribonegative layer to assemble high-performance TENGs. Experimental results revealed that the incorporation of PEI markedly enhanced the flexibility and electron-donating capability of composite films. By optimizing the material composition, the SF/PEI-based TENG achieved an open-circuit voltage as high as 275 V and a short-circuit current of 850 nA, with a maximum output power density of 13.68 μW/cm². Application tests demonstrated that the device could serve as an efficient self-powered energy source, capable of lighting up 66 LEDs effortlessly through simple hand tapping and driving small electronic components such as timers. In addition, the device can function as a highly sensitive self-powered sensor, capable of generating rapid and distinguishable electrical responses to various human motions. This work not only provides an effective strategy to overcome the intrinsic limitations of SF-based materials but also opens up new avenues for the development of high-performance and environmentally friendly technologies for energy harvesting and sensing. Full article

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

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26 pages, 5082 KB

Open AccessArticle

Weed Detection on Architectural Heritage Surfaces in Penang City via YOLOv11

by Shaokang Chen, Yanfeng Hu, Yile Chen, Junming Chen and Si Cheng

Coatings 2025, 15(11), 1322; https://doi.org/10.3390/coatings15111322 - 12 Nov 2025

Abstract

George Town, the capital of Penang, Malaysia, was inscribed as a UNESCO World Heritage Site in 2008 and is renowned for its multicultural architectural surfaces. However, these historic façades face significant deterioration challenges, particularly biodeterioration caused by weed growth on wall surfaces under [...] Read more.

George Town, the capital of Penang, Malaysia, was inscribed as a UNESCO World Heritage Site in 2008 and is renowned for its multicultural architectural surfaces. However, these historic façades face significant deterioration challenges, particularly biodeterioration caused by weed growth on wall surfaces under hot and humid equatorial conditions. Root penetration is a critical surface defect, accelerating mortar decay and threatening structural integrity. To address this issue, this study proposes YOLOv11-SWDS (Surface Weed Detection System), a lightweight and interpretable deep learning framework tailored for surface defect detection in the form of weed intrusion on heritage buildings. The backbone network was redesigned to enhance the extraction of fine-grained features from visually cluttered surfaces, while attention modules improved discrimination between weed patterns and complex textures such as shadows, stains, and decorative reliefs. For practical deployment, the model was optimized through quantization and knowledge distillation, significantly reducing computational cost while preserving detection accuracy. Experimental results show that YOLOv11-SWDS achieved an F1 score of 86.0% and a mAP@50 of 89.7%, surpassing baseline models while maintaining inference latency below 200 ms on edge devices. These findings demonstrate the potential of deep learning-based non-destructive detection for monitoring surface defects in heritage conservation, offering both a reliable tool for sustaining George Town’s cultural assets and a transferable solution for other UNESCO heritage sites. Full article

(This article belongs to the Special Issue Solid Surfaces, Defects and Detection, 2nd Edition)

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24 pages, 14785 KB

Open AccessArticle

Characteristics of the Novel Electron Beam Hardening Technology for Submicron Bainitic Steels in the Context of Its Application in the Production of Gears and Comparison with the Competitive Laser Beam Technology

by Piotr Śliwiński, Andrzej N. Wieczorek, Emilia Skołek, Marciniak Szymon, Arkadiusz Pawlikowski, Paweł Nuckowski, Łukasz Reimann, Marek S. Węglowski, Jerzy Dworak and Paweł Pogorzelski

Coatings 2025, 15(11), 1321; https://doi.org/10.3390/coatings15111321 - 12 Nov 2025

Abstract

The objective of this study was to investigate electron beam hardening (EBH) technology and compare its performance with laser beam hardening (LBH) in the context of manufacturing components such as gears, which increasingly employ submicron bainitic steels. Given the stringent demands for durability [...] Read more.

The objective of this study was to investigate electron beam hardening (EBH) technology and compare its performance with laser beam hardening (LBH) in the context of manufacturing components such as gears, which increasingly employ submicron bainitic steels. Given the stringent demands for durability and fatigue resistance of gear teeth, identifying an optimal surface hardening method is essential for extending service life. Comprehensive analyses, including light and electron microscopy, hardness testing, tribocorrosion testing, and X-ray diffraction for phase composition, were conducted. The EBH-treated layer exhibited a slightly higher hardness (by 26 HV) compared to the LBH-treated layer (average 654 HV), while the base material measured 393 HV. The EBH process produced a uniform hardness distribution with a subsurface zone of reduced hardness. In contrast, LBH resulted in a surface oxide layer absent in EBH due to its vacuum environment. Both techniques reduced the residual austenite content in the surface layer from 22.5% to approximately 1.3%–1.4%. Notably, EBH achieved comparable hardening effects with nearly half the energy input of LBH, demonstrating superior energy efficiency and industrial feasibility. Application of the developed EBH process to an actual gear component confirmed its practical potential for modern gear manufacturing. Full article

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

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22 pages, 3067 KB

Open AccessArticle

Study on the Lateral Contact Model of Paraboloids of Revolution

by Ming Guo, Ziwei Li, Shengao Wang, Mingxiang Zhou, Yilong Liu, Xiaohan Lu, Zijian Xu and Yuqing Liu

Coatings 2025, 15(11), 1320; https://doi.org/10.3390/coatings15111320 - 12 Nov 2025

Abstract

Based on actual topography measurement data, this study adopts a paraboloid of revolution to characterize asperity geometry and establishes a lateral contact model that accounts for substrate deformation and covers the full elastic–plastic process. The proposed model achieves smooth transitions in contact behavior, [...] Read more.

Based on actual topography measurement data, this study adopts a paraboloid of revolution to characterize asperity geometry and establishes a lateral contact model that accounts for substrate deformation and covers the full elastic–plastic process. The proposed model achieves smooth transitions in contact behavior, effectively avoiding non-physical oscillations and discontinuities in the elastoplastic regime exhibited by existing models. Comparative results with multiple classical models demonstrate that the proposed model maintains strict monotonicity and continuity in predicting contact load, average contact pressure, and contact stiffness. This significantly improves prediction accuracy and physical consistency, providing a more reliable theoretical tool for modeling precision mechanical joint interfaces. Full article

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20 pages, 3571 KB

Open AccessArticle

Novel Omniphobic Teflon/PAI Composite Membrane Prepared by Vacuum-Assisted Dip-Coating Strategy for Dissolved Gases Separation from Transformer Oil

by Wei Zhang, Qiwei Yang, Yuanyuan Jin, Yanzong Meng, Leyu Shen, Xuran Zhu, Haifeng Gao and Chuan Chen

Coatings 2025, 15(11), 1319; https://doi.org/10.3390/coatings15111319 - 11 Nov 2025

Abstract

Omniphobic membranes have gained extensive attention for mitigating membrane wetting in robust membrane separation owing to the super-repulsion toward water and oil. In this study, a Teflon/PAI composite membrane with omniphobic characteristics was prepared by a vacuum-assisted dip-coating strategy on the PAI hollow [...] Read more.

Omniphobic membranes have gained extensive attention for mitigating membrane wetting in robust membrane separation owing to the super-repulsion toward water and oil. In this study, a Teflon/PAI composite membrane with omniphobic characteristics was prepared by a vacuum-assisted dip-coating strategy on the PAI hollow fiber membrane. A series of characterizations on morphological structure, surface chemical composition, wettability, permeability, mechanical properties, and stability were systematically investigated for pristine PAI and Teflon/PAI composite membranes. Subsequently, the experiment was conducted to explore the oil–gas separation performance of membranes, with standard transformer oil containing dissolved gas as the feed. The results showed that the Teflon AF2400 functional layer was modified, and C-F covalent bonds were introduced on the composite membrane surface. The Teflon/PAI composite membrane exhibited excellent contact angles of 156.3 ± 1.8° and 123.0 ± 2.5° toward DI water and mineral insulating oil, respectively, indicating omniphobicity. After modification, the membrane tensile stress at break increased by 23.0% and the mechanical performance of the composite membrane was significantly improved. In addition, the Teflon/PAI composite membrane presented satisfactory thermal and ultrasonic stability. Compared to the previous membranes, the Teflon/PAI composite membrane presented a thinner Teflon AF2400 separation layer. Furthermore, the omniphobic membrane demonstrated anti-wetting performance by reaching the dynamic equilibrium within 2 h for the dissolved gases separated from the insulating oil. This suggests an omniphobic membrane as a promising alternative for oil–gas separation in monitoring the operating condition of oil-filled electrical equipment online. Full article

(This article belongs to the Special Issue Advances in Polymer Composite Coatings and Films)

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18 pages, 4280 KB

Open AccessArticle

A Damage Model for Predicting Fatigue Life of 0Cr17Ni4Cu4Nb Stainless Steel Under Near-Yield Stress-Controlled Cyclic Loading

by Xiang Cheng, Ruomin Wang, Yong Li, Zhongkang Zhou, Yingfeng Pan, He Wu and Xiaolei Chen

Coatings 2025, 15(11), 1318; https://doi.org/10.3390/coatings15111318 - 11 Nov 2025

Abstract

Fatigue damage is critical for 0Cr17Ni4Cu4Nb stainless-steel components that may operate near yield under stress-controlled cycles and occasional peak holds. This work investigates the cyclic response of 0Cr17Ni4Cu4Nb stainless-steel under near-yield-stress-controlled (NYSC) loading and proposes a unified damage framework that bridges monotonic ductile [...] Read more.

Fatigue damage is critical for 0Cr17Ni4Cu4Nb stainless-steel components that may operate near yield under stress-controlled cycles and occasional peak holds. This work investigates the cyclic response of 0Cr17Ni4Cu4Nb stainless-steel under near-yield-stress-controlled (NYSC) loading and proposes a unified damage framework that bridges monotonic ductile fracture, near-yield stress-controlled fatigue. Building on the Enhanced Lou-Yoon model, an elastic-damage term is introduced and embedded within a continuum damage mechanics framework, allowing elastic (sub-yield) and plastic (post-yield, Ultra-Low-Cycle-Fatigue/Low-Cycle-Fatigue (ULCF/LCF)) damage to be treated in a unified, path-averaged stress-state description defined by stress triaxiality and the Lode parameter. Five stress-controlled test groups are examined, with applied load amplitudes from 20.6 to 25.1 kN (equivalent stress amplitudes 858~1044 MPa) yielding fatigue lives ranging from 32 to 13,570 cycles. The extended model captures the evolution of damage origin mechanisms from elasticity-dominated to plasticity-dominated as loading severity increases, demonstrating a unified elastic-plastic damage modeling approach. As a result, it accurately predicts fatigue lives spanning two orders of magnitude with an average absolute percentage error of approximately 14.5% across all conditions. Full article

(This article belongs to the Collection Feature Paper Collection for Topic Editors and Invited Scholars in Coatings)

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25 pages, 9232 KB

Open AccessArticle

Distributed Fiber Optic Sensing for Monitoring Mining-Induced Overburden Deformation

by Shunjie Huang, Xiangrui Meng, Guangming Zhao, Xiang Cheng, Xiangqian Wang and Kangshuo Xia

Coatings 2025, 15(11), 1317; https://doi.org/10.3390/coatings15111317 - 11 Nov 2025

Abstract

The accurate real-time delineation of overburden failure zones, specifically the caved and water-conducted fracture zones, remains a significant challenge in longwall mining, as conventional monitoring methods often lack the spatial continuity and resolution for precise, full-profile strain measurement. Based on the hydrogeological data [...] Read more.

The accurate real-time delineation of overburden failure zones, specifically the caved and water-conducted fracture zones, remains a significant challenge in longwall mining, as conventional monitoring methods often lack the spatial continuity and resolution for precise, full-profile strain measurement. Based on the hydrogeological data of the E9103 working face in Hengjin Coal Mine, a numerical calculation model for the overburden strata of the E9103 working face was established to simulate and analyze the stress distribution, failure characteristics, and development height of the water-conducting fracture zones in the overburden strata of the working face. To address this problem, this study presents the application of a distributed optical fiber sensing (DOFS) system, centering on an innovative fiber installation technology. The methodology involves embedding the sensing fiber into boreholes within the overlying strata and employing grouting to achieve effective coupling with the rock mass, a critical step that restores the in situ geological environment and ensures measurement reliability. Field validation at the E9103 longwall face successfully captured the dynamic evolution of the strain field during mining. The results quantitatively identified the caved zone at a height of 13.1–16.33 m and the water-conducted fracture zone at 58–60.6 m. By detecting abrupt strain changes, the system enables the back-analysis of fracture propagation paths and the identification of potential seepage channels. This work demonstrates that the proposed DOFS-based monitoring system, with its precise spatial resolution and real-time capability, provides a robust scientific basis for the early warning of roof hazards, such as water inrushes, thereby contributing to the advancement of intelligent and safe mining practices. Full article

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

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18 pages, 1595 KB

Open AccessArticle

Effect of Nanosilica Fillers on Photopolymerisation Behaviour and Mechanical Performance of Dental Resin Composites

by Mariola Robakowska and Łukasz Gierz

Coatings 2025, 15(11), 1316; https://doi.org/10.3390/coatings15111316 - 11 Nov 2025

Abstract

The performance of dental composites is strongly dependent on the type and content of ceramic fillers incorporated into the resin matrix. In this study, the effect of nanosilica (NS) fillers on the curing kinetics, physicochemical, thermal, and mechanical properties of Bis-GMA/TEGDMA-based dental composites [...] Read more.

The performance of dental composites is strongly dependent on the type and content of ceramic fillers incorporated into the resin matrix. In this study, the effect of nanosilica (NS) fillers on the curing kinetics, physicochemical, thermal, and mechanical properties of Bis-GMA/TEGDMA-based dental composites was systematically investigated. A series of nanocomposites containing various weight fractions of NS was prepared and evaluated. The photocuring behaviour was analysed using differential scanning calorimetry (DSC), enabling the determination of polymerisation rate coefficients (propagation k_p and bimolecular termination k_t^b) and double bond conversion. The presence of nanosilica was found to influence chain mobility, as evidenced by changes in glass transition temperature (T_g). Rheological measurements provided insight into viscosity changes induced by NS incorporation, while mechanical tests confirmed reinforcement effects. A moderate but statistically significant correlation was observed between the NS content and mechanical performance. The results obtained correlate the rheological, kinetic, thermal, and mechanical properties of multiple types of silica in a single resin system using a consistent methodology. In addition, the results highlight the role of nanosilica in the regulation of the curing dynamics and the increase in the mechanical integrity of methacrylate-based dental composites, representing a promising strategy for the development of next-generation restorative materials. Full article

(This article belongs to the Special Issue Advanced Biomaterials, Coatings and Techniques: Applications in Medicine and Dentistry, 2nd Edition)

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18 pages, 5613 KB

Open AccessArticle

Preparation and Performance Study of Decanoic Acid–Stearic Acid Composite Phase-Change Ceramsite Aggregate

by Gui Yu, Qiang Yuan, Min Li, Jiaxing Tao, Jing Jiang and De Chen

Coatings 2025, 15(11), 1315; https://doi.org/10.3390/coatings15111315 - 11 Nov 2025

Abstract

In response to the problem of high energy consumption caused by inefficient temperature control of energy storage aggregates in traditional building envelope structures, this study developed a decanoic acid–stearic acid composite phase-change ceramsite aggregate to improve the thermal performance of buildings and promote [...] Read more.

In response to the problem of high energy consumption caused by inefficient temperature control of energy storage aggregates in traditional building envelope structures, this study developed a decanoic acid–stearic acid composite phase-change ceramsite aggregate to improve the thermal performance of buildings and promote the utilization of solid waste resources. Based on the theory of minimum melting, composite phase-change materials were screened through thermodynamic models. The capric acid–stearic acid (CA-SA) melt system, whose theoretical phase-transition temperature falls within the building indoor thermal environment control range (18–26 °C), was preferred as the experimental object of this study, and its characteristics were verified through step cooling curves and thermal property tests. Subsequently, the ceramsite adsorption process was optimized, and the encapsulation process was studied. Finally, the encapsulation performance was evaluated through thermal stability and stirring crushing rate tests. The results showed that the phase-transition temperature of the decanoic acid–stearic acid melt system was 24.83 °C, which accurately matched the indoor thermal environment control requirements. The ceramsite particles treated by a physical vibrating screen can reach equilibrium after 30 min of adsorption at room temperature and pressure, which is both efficient and economical. The encapsulation layer of sludge biochar cement slurry with a water–cement ratio of 0.5 and a biochar content of 3% has both thermal conductivity and encapsulation integrity. The thermal stability test showed that the percentage of leakage of sludge biochar cement slurry and epoxy resin encapsulated aggregates was 0%, and the thermal stability rating was “very stable”. However, the percentage of leakage of unencapsulated and spray-coated encapsulated aggregates was as high as 193% and 40%, respectively. The results of the mixing and crushing rate test show that although the mixing and crushing rate of sludge biochar cement slurry encapsulation is slightly higher, its production cost is much lower than that of epoxy resin, and it is also environmentally friendly. This study improves the thermal performance of buildings by using composite phase-change ceramsite aggregate, and simultaneously realizes the resource utilization of sludge biochar, providing a solution for building energy saving and efficiency that combines environmental and engineering value. Full article

(This article belongs to the Section Environmental Aspects in Colloid and Interface Science)

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28 pages, 3871 KB

Open AccessReview

A Review on Tribological Wear and Corrosion Resistance of Surface Coatings on Steel Substrates

by Xin Wang, Wenqi Zhao, Tingting Shi, Lijuan Cheng, Suwen Hu, Chunxia Zhou, Li Cui, Ning Li and Peter K. Liaw

Coatings 2025, 15(11), 1314; https://doi.org/10.3390/coatings15111314 - 11 Nov 2025

Abstract

Surface coatings have proven highly effective in addressing the critical challenges of friction, wear, and corrosion on steel substrates, which are responsible for over 80% of mechanical failures in industrial applications. Recent research highlights that advanced coatings—such as ceramic carbides/nitrides, high-entropy alloys, and [...] Read more.

Surface coatings have proven highly effective in addressing the critical challenges of friction, wear, and corrosion on steel substrates, which are responsible for over 80% of mechanical failures in industrial applications. Recent research highlights that advanced coatings—such as ceramic carbides/nitrides, high-entropy alloys, and metal-matrix composites—significantly enhance hardness, wear resistance, and environmental durability through mechanisms including protective oxide film formation, solid lubrication, and microstructural refinement. Moreover, these coatings exhibit robust performance under combined tribological-corrosive (tribocorrosion) conditions, where synergistic interactions often accelerate material degradation. Key developments include multilayer and composite architectures that balance hardness with toughness, self-lubricating coatings capable of in situ lubricant release, and active or self-healing systems for sustained corrosion inhibition. Despite these advances, challenges remain in predicting coating lifetime under multifield service conditions and optimizing interfacial adhesion to prevent delamination. Future efforts should prioritize multifunctional coating designs, improved tribocorrosion models, and the integration of sustainable materials and AI-driven process optimization. This review consolidates these insights to support the development of next-generation coatings for extending the service life of steel components across demanding sectors such as marine, aerospace, and energy systems. Full article

(This article belongs to the Special Issue Manufacturing and Surface Engineering, 5th Edition)

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18 pages, 4490 KB

Open AccessArticle

Influence of Layer Configuration on the Mechanical, Tribological and Corrosion Performance of Ti/TiN Multilayer Coatings

by Zarina Aringozhina, Nurtoleu Magazov, Bauyrzhan Rakhadilov, Yelaman Batanov, Ainur Serikbaikyzy and Arystanbek Kussainov

Coatings 2025, 15(11), 1313; https://doi.org/10.3390/coatings15111313 - 11 Nov 2025

Abstract

This study investigates the influence of multilayer architecture on the mechanical, corrosion, and tribological properties of Ti/TiN coatings deposited on biomedical Ti-6Al-4V alloy. Nine multilayer configurations were prepared by DC/RF magnetron sputtering using metallic Ti and ceramic TiN targets, with a fixed TiN/Ti [...] Read more.

This study investigates the influence of multilayer architecture on the mechanical, corrosion, and tribological properties of Ti/TiN coatings deposited on biomedical Ti-6Al-4V alloy. Nine multilayer configurations were prepared by DC/RF magnetron sputtering using metallic Ti and ceramic TiN targets, with a fixed TiN/Ti ratio of 3:1 and varying total numbers of layers (3, 5, and 7) and deposition times (30, 60, and 120 min). A strict application of the 10% indentation depth rule was implemented to eliminate substrate effects, which revealed significantly higher intrinsic hardness values (540–740 HV) and indentation moduli (124–143 GPa) compared to the substrate (353 HV; 114 GPa). In contrast, conventional higher-load testing underestimated coating performance due to substrate dominance. Among the investigated architectures, the Ti/TiN-7 configuration exhibited the best balance of properties, combining high hardness (~690 HV), modulus (~137 GPa), improved corrosion resistance (Ecorr up to −0.13 V, Icorr reduced by an order of magnitude), and stable abrasive wear behavior. These findings demonstrate that both bilayer number and deposition time critically determine the mechanical and functional response of Ti/TiN multilayers. The results provide practical guidelines for the reliable characterization and design of multilayer coatings for biomedical and aerospace applications. Full article

(This article belongs to the Section Tribology)

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