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Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings

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A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Thin Films".

Deadline for manuscript submissions: closed (30 April 2026) | Viewed by 16521

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Special Issue Editor

Prof. Dr. Min Zhang

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Guest Editor

School of Physics & Electronic Technology, Liaoning Normal University, Huanghe Road, No. 850, Shahekou District, Dalian, China
Interests: photoelectric detection films and devices; hard coatings by physical vapor deposition (PVD), and chemical vapor deposition (CVD) methods; solar selective absorber coatings; first-principle calculations for nitrides and oxides
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Special Issue Information

Dear Colleagues,

Functional thin films and hard protective coatings are indispensable in advancing material performance across a broad range of industrial and technological domains. This Special Issue seeks to showcase state-of-the-art research and emerging trends in the design, synthesis, and applications of these coatings. It aims to explore their role in addressing challenges in durability, functionality, and environmental sustainability. Contributions are encouraged in areas ranging from fundamental studies to innovative applications, focusing on coating methods, novel materials, and advanced characterization techniques.

This Special Issue will address (but is not limited to) the following topics:

- Advanced deposition techniques for thin films and coatings, including Physical Vapor Deposition(PVD), Chemical Vapor Deposition(CVD), plasma electrolytic oxidation (PEO), and additive manufacturing methods like laser and 3D printing.

- Thin films for photoelectric detection, including those for UV, infrared detection, and other electromagnetic signals.

- Conducting oxide thin films transparent across infrared, visible, or UV spectra.

- High-entropy alloy coatings and their nitride or oxide derivatives.

- Hard coatings for enhanced wear, corrosion, and oxidation resistance.

- Diamond- and carbon-based thin films and coatings.

- Optical thin film materials: their design, preparation, and applications.

- Functional thin films and coatings for aerospace applications, including thermal control and protection, wear resistance, and anti-corrosion properties.

- Surface modification techniques, such as nitriding, boriding, and aluminizing, to enhance coating performance.

- Multi-layered, nanostructured, and composite thin films for AI and machine learning.

- Coatings with self-healing, anti-reflective, or photocatalytic functionalities.

- Computational & modeling for film/coating design and performance prediction.

I look forward to receiving your contributions.

Prof. Dr. Min Zhang
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Coatings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

functional thin films and devices
hard protective coatings
advanced deposition techniques
surface treatment & modification
computations and modeling for materials design

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Published Papers (13 papers)

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Editorial

Jump to: Research, Review

6 pages, 178 KB

Open AccessEditorial

Editorial for Special Issue: “Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings”

by Min Zhang

Coatings 2026, 16(5), 616; https://doi.org/10.3390/coatings16050616 - 20 May 2026

Abstract

As guest editor of Coatings, it is my great pleasure to introduce this Special Issue focused on “Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings” [...] Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

Research

Jump to: Editorial, Review

16 pages, 13304 KB

Open AccessArticle

Atomic-Level Investigation of Ni-W Film Growth on Al(001) Surface: Molecular Dynamics Simulation

by Desen Cheng, Shuaijiang Ma, Yongchao Zhu, Mengya Li and Yajun Zhou

Coatings 2026, 16(4), 503; https://doi.org/10.3390/coatings16040503 - 21 Apr 2026

Viewed by 388

Abstract

Molecular dynamics (MD) simulations were performed to investigate the dynamic deposition behavior, growth mechanism, and mechanical properties of nickel–tungsten (Ni-W) alloy films on single-crystal Al(001) substrates. The results demonstrate that the incorporation of W atoms lowers the Ehrlich–Schwoebel (ES) barrier for Ni adatoms, facilitating downhill diffusion and effectively suppressing Volmer–Weber (VW) mode, thereby improving surface morphology and reducing film roughness. Additionally, W atoms exhibit a tendency to segregate at grain boundaries, inducing lattice distortion and structural disorder. With increasing W content (≥15 at%), the films undergo a transition from a nanocrystalline to an amorphous structure. Nanoindentation simulations reveal that film hardness increases with W content, with the strengthening mechanism being composition-dependent: dislocation pinning dominates at low W concentrations (≤5 at%), while the formation of an amorphous structure emerges as the primary strengthening mechanism at higher W contents (≥15 at%). This work elucidates the growth regulation and strengthening mechanisms of Ni-W films from an atomic-scale perspective, providing a theoretical foundation and simulation-driven guidance for the design and optimization of high-performance, environmentally benign Ni-W coatings. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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15 pages, 3058 KB

Open AccessArticle

Influence of N₂/Ar Flow Ratio on the Microstructure and Electrochemical Capacitive Performance of TiN Thin-Film Electrodes for Micro-Supercapacitors

by Jiaxin Tan, Lin Yi, Min Zhang and Suyuan Bai

Coatings 2026, 16(1), 69; https://doi.org/10.3390/coatings16010069 - 7 Jan 2026

Cited by 1 | Viewed by 536

Abstract

With the rapid development of the Internet of Things (IoT), micro-energy storage devices face increasing demands for miniaturization, high energy density, and high power density. Owing to their excellent electrical conductivity and mechanical strength, TiN thin films are promising candidates for micro-supercapacitor electrodes. In this work, TiN thin films were prepared by direct current magnetron sputtering under different N₂/Ar flow ratios. The effects of the N₂/Ar flow ratio on the crystal structure, surface morphology, roughness, and electrochemical capacitive performance of TiN thin films were systematically investigated. The results show that at lower N₂/Ar flow ratios, the films consist of a mixture of TiN and Ti₂O₃ phases, while at higher N₂/Ar ratios, single-phase TiN with a preferred orientation along the (220) plane is detected in the obtained films. AFM measurements indicate that the root mean square roughness first increases and then decreases with increases in N₂/Ar flow ratios, and it reaches a maximum of around 15.9 nm when the N₂/Ar flow ratio is 5:15. XPS results show that the 5:15 sample contains the highest oxygen vacancy concentration, offering it the best conductivity, which is confirmed by four-probe measurements. Electrochemical tests demonstrate that the N₂/Ar flow ratio has a significant influence on the specific capacitance of TiN films, with the highest value of 3.29 mF/cm² achieved at a N₂/Ar flow ratio of 5:15, which is likely due to the rough and porous surface and much better conductivity of the as-deposited films. This study provides an important experimental basis for optimizing the performance of TiN thin-film electrodes. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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25 pages, 6536 KB

Open AccessArticle

Light-Induced Interfacial Charge Transport of In₂O₃/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum

by Xingfa Ma, Xintao Zhang, Mingjun Gao, Ruifen Hu, You Wang and Guang Li

Coatings 2025, 15(12), 1448; https://doi.org/10.3390/coatings15121448 - 8 Dec 2025

Viewed by 543

Abstract

To increase the use of the near-infrared (NIR) light from In₂O₃, a nanocomposite of In₂O₃/reduced graphene oxide was synthesised. To improve adhesion to the substrates, a small amount of PVA (polyvinyl alcohol) was added to the nanocomposite. Results showed that adding an appropriate amount of PVA to the nanocomposite remarkably enhanced the ability to extract photogenerated carriers due to interface optimisation based on the grain boundary filling with PVA and charge tunnelling effects. The nanocomposites exhibited photoconductive switching responses from the visible light region to the near-infrared range. Meanwhile, the organic/inorganic hybrid coating on silk fibres exhibited mutual conversion of positive and negative photoconductivity, as well as electrical switching responses to applied strain. Furthermore, it was found that a photoelectric signal could still be determined with zero bias after the In₂O₃/reduced graphene oxide nanocomposite had been stored for over four years. This reflects that the nanocomposites have an internal electric field that promotes the transfer of photogenerated carriers and prevents the recombination of photogenerated electrons and holes. Similar results were also obtained by adding an appropriate amount of other non-conjugated polymers, such as dendrimers. Physical mechanisms are discussed. This study provides reference values for the development of multifunctional organic/inorganic hybrids integrating non-conjugated polymer components to enhance specific properties. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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15 pages, 3479 KB

Open AccessArticle

Effect of Nd:YAG Nanosecond Laser Ablation on the Microstructure and Surface Properties of Coated Hardmetals

by G. A. Leal, C. M. Moreno, R. C. Hernández, E. Mejía-Ospino and L. C. Ardila

Coatings 2025, 15(12), 1413; https://doi.org/10.3390/coatings15121413 - 2 Dec 2025

Cited by 1 | Viewed by 747

Abstract

Nanosecond-pulsed Nd:YAG laser ablation was investigated as a method for removing Al Ti-based hard coatings deposited on WC–Co hardmetal inserts. Systematic variation in laser parameters identified conditions for complete coating removal while preserving substrate integrity. The laser was operated at 532 nm, under a range of fluences (0.1–11.7 J/cm²), pulse delays (20–180 µs), and pulse numbers (1–300). LIBS qualitative monitoring enabled precise ablation progress by identifying Ti, Al, and O layers, and later the detection of Co and W signals. Scanning electron microscopy (SEM/EDS) and optical profilometry confirmed that 5–10 pulses at intermediate delays (60–80 µs, 4.8–7.1 J/cm²) provided complete removal of ~18 µm-thick coatings while maintaining substrate integrity. In contrast, higher energies and excessive pulses caused localized melting and surface irregularities. These results demonstrate that Nd:YAG laser ablation, especially when coupled with LIBS, offers a precise, fast, and environmentally alternative to conventional chemical stripping methods for the refurbishment and recycling of cutting tools. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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16 pages, 2035 KB

Open AccessArticle

AlN Passivation-Enhanced Mg-Doped β-Ga₂O₃ MISIM Photodetectors for Highly Responsive Solar-Blind UV Detection

by Jiaxin Tan, Lin Yi, Mingyue Lv, Min Zhang and Suyuan Bai

Coatings 2025, 15(11), 1312; https://doi.org/10.3390/coatings15111312 - 10 Nov 2025

Cited by 4 | Viewed by 1051

Abstract

Mg-doped gallium oxide films were prepared on single crystal sapphire substrates through radio frequency magnetron sputtering technology, and then AlN films of different thicknesses were deposited on them as passivation layers. Finally, Pt interdigitated electrodes were prepared through mask plate and ion sputtering technology to make metal–insulator–semiconductor–insulator–metal (MISIM) photodetectors. The influence of the AlN passivation layer on the optical properties and photodetection performance of the device was investigated using UV-Vis (ultraviolet-visible absorption spectroscopy) spectrophotometer and a Keith 4200 semiconductor tester. The device’s performance was significantly enhanced. Among them, the MISIM-structured device achieves a responsivity of 2.17 A/W, an external quantum efficiency (EQE) of 1100%, a specific detectivity (D*) of 1.09 × 10¹² Jones, and a photo-to-dark current ratio (PDCR) of 2200. The results show that different thicknesses of AlN passivation layers have an effect on the detection performance of Mg-doped β-Ga₂O₃ films in the UV detection of the solar-blind UV region. The AlN’s thickness has little effect on the bandgap when it is 3 nm and 5 nm, and the bandgap increases at 10 nm. The transmittance of the film increases with the increase in AlN thickness and decreases when the AlN’s thickness increases to 10 nm. The photocurrent exhibits a non-monotonic dependence on AlN thickness at 10 V, and the dark current gradually decreases. The thickness of the AlN passivation layer also has a significant impact on the response characteristics of the detector, and the response characteristics of the device are best when the thickness of the AlN passivation layer is 5 nm. The responsiveness, detection rate, and external quantum efficiency of the device first increase and then decrease with the thickness of the AlN layer, and comprehensive performance is best when the thickness of the AlN passivation layer is 5 nm. The reason is that the AlN layer plays a passivating role on the surface of Ga₂O₃ films, reducing surface defects and inhibiting its capture of photogenerated carriers, while the appropriate thickness of the AlN layer increases the barrier height at the semiconductor interface, forming a built-in electric field and improving the response speed. Finally, the AlN layer inhibits the adsorption and desorption processes between the photogenerated electron–hole pair and O₂, thereby retaining more photogenerated non-equilibrium carriers, which also helps enhance photoelectric detection performance. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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12 pages, 1865 KB

Open AccessArticle

The Effect of Current Density and Cathode Position on the Corrosion Resistance and Thermal Emission Properties of Nickel Electroplated Layers on Brass Surfaces

by Lin Zhang, Mingyue Lv, Haoqian Zhang, Xuan Zhang, Mingyue Zhao and Min Zhang

Coatings 2025, 15(11), 1276; https://doi.org/10.3390/coatings15111276 - 3 Nov 2025

Cited by 1 | Viewed by 1553

Abstract

Brass components are widely used in heat dissipation and thermal emission devices due to their high thermal conductivity and ease of processing. However, these applications demand good thermal oxidation resistance, high emissivity, and excellent corrosion resistance. In this study, nickel coatings were deposited on brass substrates by direct current electroplating, and the effects of current density and cathode configuration on the microstructure, emissivity, and corrosion resistance of the coatings were systematically investigated. The results show that the emissivity of the coatings first increased and then decreased with increasing current density. Optimal performance was achieved when the cathode and anode were positioned perpendicular to the horizontal plane at a current density of 3.0 A·dm⁻². Under these conditions, the coatings exhibited a smooth, uniform, and dense microstructure, with evenly distributed metallic grains. Electrochemical polarization and impedance measurements further confirmed the superior corrosion resistance of this coating, with a minimum corrosion current density of 0.259 μA·cm⁻², a maximum polarization resistance of 6381.55 Ω·cm², and a minimum corrosion rate of 0.023 mm/a. These findings demonstrate a simple and effective approach to enhancing both the emissivity and corrosion resistance of brass substrates, offering practical value for thermal management applications. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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19 pages, 7946 KB

Open AccessArticle

Synergistic Disinfection of Photocatalytic Nanomaterials Exposed to UVC, Electricity and Magnetic Fields Against Candida albicans

by María Cristina Grijalva-Castillo, Renee Joselin Saénz-Hernández, Adrián Alberto Cobos-Márquez, Francisco Alonso Herrera-Ojeda, Fernando Efraín Díaz-Chávez, Irving Ricardo Acosta-Galindo, César Leyva-Porras, Alva Rocío Castillo-González, María Alejandra Favila-Pérez, Celia María Quiñonez-Flores, Javier Camarillo Cisneros and Carlos Arzate-Quintana

Coatings 2025, 15(8), 968; https://doi.org/10.3390/coatings15080968 - 19 Aug 2025

Cited by 1 | Viewed by 1609

Abstract

Nosocomial infections caused by Candida albicans pose serious challenges to healthcare systems due to their persistence on medical surfaces and resistance to conventional disinfectants. This study evaluates antifungal properties of SnO₂ doped with silver and cuprite nanoparticles and WO₃ thin films, as well as cobalt (CoFe₂O₄) and cobalt–nickel (Co_0.5Ni₀.₅Fe₂O₄) ferrite nanoparticles, activated by ultraviolet C (UVC) radiation, direct electric current (up to 100 V), and magnetic fields. SnO₂ films were synthesized by Spray Pyrolysis and WO₃ by Sputtering deposition, Ferrites nanoparticles by sol–gel, while metallic nanoparticles were synthetized via chemical reduction. Characterization consisted mainly of SEM, TEM, and XRD, and their antimicrobial activity was tested against C. albicans. WO₃ films achieved 86.2% fungal inhibition after 5 min of UVC exposure. SnO₂ films doped with nanoparticles reached 100% inhibition when combined with UVC and 100 V. Ferrite nanoparticles alone showed moderate activity (21.9%–40.4%) but exhibited strong surface adhesion to fungal cells, indicating potential for magnetically guided antifungal therapies. These results demonstrate the feasibility of using multifunctional nanomaterials for rapid, non-chemical disinfection. The materials are low-cost, scalable, and adaptable to hospital settings, making them promising candidates for reducing healthcare-associated fungal infections through advanced surface sterilization technologies. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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11 pages, 2562 KB

Open AccessArticle

Biocompatibility of Titanium Oxide Nanotubes Layer Formed on a Ti-6Al-4V Dental Implant Screw in hFOB Cells In Vitro

by José Luis Castrejón Flores, Ángel Daniel Campos Juarez, Alexis Chino Ulloa, Fernando Nava Palafox, David Cruz Ortiz and Itzel Pamela Torres Avila

Coatings 2025, 15(6), 715; https://doi.org/10.3390/coatings15060715 - 13 Jun 2025

Cited by 1 | Viewed by 1768

Abstract

The surface modification of dental implants with nanostructured films enables the development of the next generation of biomaterials that promote osseointegration. In this study, a uniform layer of titanium oxide nanotubes (TNTs) was successfully formed on a Ti-6Al-4V dental implant screw through anodic oxidation. TNTs were morphologically characterized by Scanning Electron Microscopy (SEM), obtaining dimensions of 64.88 ± 10 nm in diameter and 5.34 ± 5 µm in length. Additionally, a crystal size of 23.45 nm was determined by X-ray diffraction (XRD) analysis. The TNT layer on the dental implant screw was evaluated in an in vitro system in direct contact with human osteoblast cells (hFOB) for 24 h and 48 h, finding cell growth near to the screw threads. Further, the biocompatibility of the dental screw coated with TNTs was evaluated using a flow cytometric assay with 7-AAD, demonstrating that cell viability was not affected at 24 h and 48 h. This study opens the perspective of the study of inflammation and osseointegration induced by implants coated with TNTs. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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14 pages, 3417 KB

Open AccessArticle

The Influence of Water Content in Ethylene Glycol Electrolyte on Magnesium Plasma Electrolytic Fluorinated Coating

by Yifeng Yang, Hao Wang, Xuchen Lu and Cancan Liu

Coatings 2025, 15(6), 701; https://doi.org/10.3390/coatings15060701 - 11 Jun 2025

Viewed by 1116

Abstract

Plasma electrolytic fluorination (PEF) of AZ31 magnesium alloy was carried out by adding different ratios of water to the ethylene glycol-ammonium fluoride electrolyte. The structural composition of the coatings was characterized using SEM, XRD, and EDS, and the effects of water content on the microstructure and corrosion resistance of the PEF coatings were analyzed. The results showed that the addition of water promoted the ionization of ammonium fluoride and increased the conductivity of the glycol electrolyte, which led to a decrease in the termination voltage. However, the coating thickness was not changed by the addition of water. The O element in water was not enough to compete with the F element in the electrolyte and had a small effect on the PEF coating composition, which was still dominated by MgF₂. The addition of water had an effect on the structure of the coating: with an increase in water content, the number of coating penetration holes decreases, and the continuity is enhanced. The pores on the surface of the coating tended to be levelled off and transitioned to the typical coating structure of PEO (plasma electrolytic oxidation). The addition of water to the glycol electrolyte was conducive to improving the corrosion resistance of the coatings. The corrosion resistance of PEF coatings in neutral NaCl corrosive medium firstly increased and then decreased, and the strongest corrosion resistance was obtained when the ratio of glycol and water is 6:4. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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13 pages, 1995 KB

Open AccessArticle

Tuning Electrical and Optical Properties of SnO₂ Thin Films by Dual-Doping Al and Sb

by Yuxin Wang, Hongyu Zhang, Xinyi Zhang, Zhengkai Zhou and Lu Wang

Coatings 2025, 15(6), 669; https://doi.org/10.3390/coatings15060669 - 30 May 2025

Cited by 6 | Viewed by 2341

Abstract

The Al-Sb co-doped SnO₂ composite thin films were prepared by the sol–gel spin-coating method. The structure, morphology, optical and electrical properties of the samples were investigated using XRD, XPS, SEM, UV-Vis spectroscopy, and Hall effect tester, respectively. It was found that when the aluminum doping amount was 15 at%, the resistivity of the sample was the lowest, and the overall optoelectronic performance was the best. Moreover, the Al-SnO₂ composite thin film transformed from an n-type semiconductor to a p-type semiconductor. When Al and Sb were co-doped, the carrier concentration increased significantly from 4.234 × 10¹⁹ to 6.455 × 10²⁰. Finally, the conduction type of the Al-Sb-SnO₂ composite thin film changed from p-type to n-type. In terms of optical performance, the transmittance of the Al-Sb co-doped SnO₂ composite thin films in the visible light region was significantly improved, reaching up to 80% on average, which is favorable for applications in transparent optoelectronic devices. Additionally, the absorption edge of the thin films exhibited a blue-shift after co-doping, indicating an increase in the bandgap energy, which can be exploited to tune the light-absorption properties of the thin films for specific photonic applications. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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Review

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32 pages, 1763 KB

Open AccessReview

Research Progress on Doping Control Technology for SnSe Thin Film Characteristics

by Zhengjie Guo, Chi Zhang, Fuyueyang Tan, Jinhui Zhou, Xi Cao, Xuezhi Li, Yuying Feng, Yixian Xie, Kaiquan Lei, Wenbin Li, Yikun Yang, Chenyao Huang, Zaijin Li and Yi Qu

Coatings 2026, 16(2), 170; https://doi.org/10.3390/coatings16020170 - 30 Jan 2026

Viewed by 712

Abstract

With the increasingly prominent issues of energy shortage and environmental pollution, the development of clean energy materials has become a core topic in the academic community. SnSe, as a material with moderate bandgap, a high light absorption coefficient, and environmental friendliness, has shown broad application prospects in the fields of photovoltaics and thermoelectrics. However, pure SnSe thin films have inherent defects, low carrier concentration, and high recombination rates, which limit their photoelectric conversion efficiency. This article provides a detailed overview of the characteristics of band engineering control technology, defect control technology, and carrier concentration control technology, as well as the improvements in the characteristics of SnSe thin films that they bring. This article systematically reviews the research progress on doping control technology for SnSe thin films characteristics in recent years and analyzes and discusses the differences in typical doping elements on SnSe thin films characteristics, such as optical bandgap and absorption coefficient, and applicable application scenarios, such as photovoltaics, near-infrared/infrared detection, and thermoelectric and flexible optoelectronic devices. Furthermore, the interaction between the doping mechanism of dopants and natural defects, as well as the influence of the structural parameters of doped films on doping efficiency, were analyzed, and a predictive design route for the doping mechanism of SnSe films was proposed. Finally, the influence of different atomic fractions on the characteristics of SnSe thin films was discussed. Low atomic fractions are beneficial for bandgap tuning and absorption enhancement; high atomic fractions can easily introduce phase separation and non-radiative recombination. It is suggested that future researchers can continue to focus on the precise control of atomic fractions, exploration of new element co-doping, and industrial large-scale production applications, providing theoretical guidance for the design and application of SnSe thin films in photothermal devices. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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21 pages, 3658 KB

Open AccessEditor’s ChoiceReview

An Overview of Metallic Abradable Coatings in Gas Turbine Engines

by Kaue Bertuol, Bruno Edu Arendarchuck and Pantcho Stoyanov

Coatings 2025, 15(10), 1216; https://doi.org/10.3390/coatings15101216 - 16 Oct 2025

Cited by 4 | Viewed by 2642

Abstract

This review presents a comprehensive overview of metallic abradable coatings and the advanced testing methodologies used to evaluate their performance in gas turbine engines. Abradable materials are engineered to act as sacrificial coatings, enabling minimal blade tip wear while maintaining tight clearances between rotating blades and stationary components. Such functionality is critical in aerospace applications, where engines operate at high rotational speeds and across wide temperature ranges. The review examines the principal factors governing the design and selection of metallic-based abradable coatings, including material composition, thermal stability, and microstructural tailoring through the addition of phase modifiers, porosity formers, and solid lubricants. The performance of various metallic matrix materials is also discussed concerning their operational temperature ranges and wear characteristics. Particular attention is given to abradability evaluation methods, emphasizing the need to replicate engine-representative conditions to capture blade–coating interactions, frictional behavior, and wear mechanisms. This review consolidates advances in material compositions, microstructural engineering, and experimental testing, integrating perspectives from materials science, tribology, and methodology to guide the development of next-generation turbine coatings. It specifically addresses the lack of a unified review linking material design, thermal spray processes, and performance evaluation by summarizing key compositions, microstructures, and testing methods. Full article

(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)

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