Coatings

Research

Jump to: Other

8 pages, 1479 KiB

Open AccessArticle

Controllable Water Penetration through a Smart Brass Mesh Modified by Mercaptobenzoic Acid and Naphthalenethiol

by Cong-Cong Luan, Yu-Ping Zhang, Cheng-Xing Cui, De-Liang Chen, Yuan Chen and Meng-Jun Chen

Coatings 2022, 12(11), 1729; https://doi.org/10.3390/coatings12111729 - 12 Nov 2022

Cited by 2 | Viewed by 969

Abstract

In this paper, a novel pH-responsive brass mesh modified by 3-mercaptobenzoic acid (MBA) and 2-naphthalenethiol (NPT) was demonstrated via a facile chemical etching method followed by surface modification. The smart wettability was dependent on the assembled MBA and NPT with suitable thiol proportions. [...] Read more.

In this paper, a novel pH-responsive brass mesh modified by 3-mercaptobenzoic acid (MBA) and 2-naphthalenethiol (NPT) was demonstrated via a facile chemical etching method followed by surface modification. The smart wettability was dependent on the assembled MBA and NPT with suitable thiol proportions. The on–off control of water penetrating intelligently into the nanostructured brass mesh substrate was carried out by the pH change in the outside environment. The brass mesh modified with X_NPT = 0.4 (mole fraction of NBT in the mixed solution) exhibited the strongest pH responsivity from superhydrophobicity to superhydrophilicity. Furthermore, the resulted Janus membrane (JM) fabricated by the integration of a smart brass mesh and hydrophobic Ni foam could be used as a water diode in air and liquid systems. Unidirectional penetration for the water droplet was realized by the resulting smart JM with a hydrophobic upper layer and a pH-responsive layer below. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

14 pages, 20496 KiB

Open AccessArticle

Exploring the Effect of Pt Addition on the Fracture Behavior of CrN Coatings by Finite Element Simulation

by Haifeng Sun, Weilun Zhang, Yongjun Feng, Suying Hu, Hua Tian and Zhiwen Xie

Coatings 2022, 12(8), 1131; https://doi.org/10.3390/coatings12081131 - 05 Aug 2022

Cited by 2 | Viewed by 1337

Abstract

Previous research confirmed that Pt addition induced a prominent refinement effect of CrN coating, resulting in an enhanced conductivity and corrosion resistance. In this work, a detailed finite element simulation and scratch test were employed to calculate and characterize the fracture failure behaviors [...] Read more.

Previous research confirmed that Pt addition induced a prominent refinement effect of CrN coating, resulting in an enhanced conductivity and corrosion resistance. In this work, a detailed finite element simulation and scratch test were employed to calculate and characterize the fracture failure behaviors (stress distribution, crack damage process, critical coating load, and coating–substrate adhesion energy) of CrN coatings with different Pt contents. Simulation results showed that the synergistic action of dynamic scratch load and extrusion load induced the fracture of the coatings. S11 and S22 caused transverse cracks in the CrN coating, S11 caused longitudinal cracks in the CrN-Pt coating and CrN-3Pt coatings, S22 led to the inclined propagation of cracks in these coatings, and S11 and S22 jointly induced the separation of the coating from the substrate. The doping Pt element in the CrN coating will make the coating easier to fracture and reduce the adhesion strength between the coating and substrate. Scratch test results revealed that adding Pt into the CrN coating will make this coating easier to fracture and cause more serious damage; the simulation results are in good accordance with the scratch test characterizations. The current founding provided a comprehensive understanding for the fracture damage mechanism of Pt-doped nitride coatings. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

12 pages, 3759 KiB

Open AccessArticle

Corrosion Degradation Behaviors of Ti6Al4V Alloys in Simulated Marine Environments

by Wei Chen, Dalu Zhang, Enlei Wang, Feng Yan, Lin Xiang and Zhiwen Xie

Coatings 2022, 12(7), 1028; https://doi.org/10.3390/coatings12071028 - 20 Jul 2022

Cited by 4 | Viewed by 1607

Abstract

Detailed tests and characterizations were used to investigate the corrosion degradation behaviors of Ti6Al4V alloys in simulated marine environments. These alloys suffered from very slight pitting and a miniscule weight loss of 0.018 mg/cm² during the 50 cycle salt spray exposure but [...] Read more.

Detailed tests and characterizations were used to investigate the corrosion degradation behaviors of Ti6Al4V alloys in simulated marine environments. These alloys suffered from very slight pitting and a miniscule weight loss of 0.018 mg/cm² during the 50 cycle salt spray exposure but experienced significant oxygen erosion in the high-temperature oxidation test, resulting in a high weight gain of 2.657 mg/cm² at 400 h. The oxidation and degradation reactions simultaneously occurred during the high-temperature hot salt test. The chlorine (Cl₂) induced by the eutectic reaction of the mixed salts accelerated the degradation of the substrate and led to a higher weight gain of 4.265 mg/cm² at 400 h. In contrast, this alloy suffered from severe corrosion damage during the high-temperature hot salt–water vapor synergy test. The degradation of TiO₂, Al₂O₃, and V₂O₅ was aggravated by the synergistic action of chlorine salt and water. The reaction forming hydrochloric acid (HCl) further degraded the matrix metal and consequently led to a high weight loss of 16.358 mg/cm² at 400 h. These current findings provide a comprehensive understanding for the degradation mechanisms of Ti alloys in these specific marine environments. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

18 pages, 6035 KiB

Open AccessArticle

Vibration Reduction Characteristics and Vibration Control of Aviation Hydraulic Pipeline by Hard Coating

by Zhining Cui, Xiaoguang Yu, Ziqing Ran, Jiaming Liu, Chunqiu Li and Lei Gao

Coatings 2022, 12(6), 775; https://doi.org/10.3390/coatings12060775 - 04 Jun 2022

Cited by 6 | Viewed by 1742

Abstract

Aviation hydraulic pipelines are an important channel for power transmission in aviation hydraulic systems. Due to long-term exposure to complex vibration environments, hydraulic pipeline systems are susceptible to accumulated fatigue damage failure, which poses a great threat to aircraft safety and reliability. At [...] Read more.

Aviation hydraulic pipelines are an important channel for power transmission in aviation hydraulic systems. Due to long-term exposure to complex vibration environments, hydraulic pipeline systems are susceptible to accumulated fatigue damage failure, which poses a great threat to aircraft safety and reliability. At present, there are only passive ways to reduce hydraulic pipeline vibration, such as adding vibration isolators and damping bearings. These methods have a poor vibration damping effect and are not safe. In this study, a hard coating was used as a new vibration reduction method for aviation hydraulic pipelines to reduce the damage caused by vibrations. For this purpose, three different hard-coating materials were optimally selected, and model creation, finite element analysis, and experimental research were carried out to study the vibration responses of hard-coated aviation hydraulic pipelines under the actual working conditions of an aircraft. The optimal solution was obtained through orthogonal experiments. The vibration reduction rate of the aviation hydraulic pipelines could reach 20.33% under the constant-frequency excitation of the low-pressure rotor of the engine, and the vibration reduction rate under the constant-frequency excitation of the high-pressure rotor could reach 26.60%. The rationality of the model was verified, and it was proven that the hard coating could meet the demands of vibration control in practical engineering and provide a reference for the vibration analysis and vibration control design of aviation hydraulic piping systems. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

14 pages, 4663 KiB

Open AccessArticle

Mechanical Properties and Residual Stress Measurement of TiN/Ti Duplex Coating Using HiPIMS TiN on Cold Spray Ti

by Nhat Minh Dang, Wen-Yen Lin, Zhao-Ying Wang, Sima Ahmad Alidokht, Richard R. Chromik, Terry Yuan-Fang Chen and Ming-Tzer Lin

Coatings 2022, 12(6), 759; https://doi.org/10.3390/coatings12060759 - 01 Jun 2022

Cited by 4 | Viewed by 2347

Abstract

This study investigated the mechanical properties and the residual stress of high-power impulse magnetron sputtering (HiPIMS) titanium nitride (TiN) thin film capping on cold spray titanium (Ti) coating. This TiN/Ti duplex coating was deposited on the Ti substrate, and the cold spray titanium [...] Read more.

This study investigated the mechanical properties and the residual stress of high-power impulse magnetron sputtering (HiPIMS) titanium nitride (TiN) thin film capping on cold spray titanium (Ti) coating. This TiN/Ti duplex coating was deposited on the Ti substrate, and the cold spray titanium (Ti) coating was prepared in three cases with different numbers of layers. The study determined Young’s modulus, hardness, and roughness of TiN thin film and cold spray Ti coatings by nano-indentation and AFM. The residual stress measurement of TiN/Ti duplex coating was conducted using the ring-core drilling method. A focused ion beam (FIB) drilled the TiN/Ti duplex coating with various milling depth steps. The corresponding images were obtained with a scanning electron microscope (SEM). The relationship between surface deformations and relaxation stress after each milling depth step was obtained using the digital image correlation (DIC) method. The results showed TiN/Ti duplex coating exhibited excellent mechanical properties, and the residual stresses were not significantly changing with different Ti cold spray substrates, showing the feasibility of coating technology for the future applications in the aerospace industry. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

20 pages, 10013 KiB

Open AccessArticle

Influence of Particle Concentration on the Elemental Penetration Region and Properties of Ni-P-SiC Composite Coatings Prepared through Sandblasting and Scanning Electrodeposition on 45 Steel Surfaces

by Zhengwei Zhang, Jieyu Xian, Hongbin Wu, Meifu Jin and Zhenyu Shen

Coatings 2021, 11(10), 1237; https://doi.org/10.3390/coatings11101237 - 12 Oct 2021

Cited by 5 | Viewed by 1721

Abstract

Ni-P-SiC composite coating was prepared on 45 steel surfaces through sandblasting and scanning electrodeposition to explore the relationship between element penetration region and composite coating properties. The single-factor control variable method with particle concentration as the research variable was used. Results showed that [...] Read more.

Ni-P-SiC composite coating was prepared on 45 steel surfaces through sandblasting and scanning electrodeposition to explore the relationship between element penetration region and composite coating properties. The single-factor control variable method with particle concentration as the research variable was used. Results showed that with the gradually increasing concentration of SiC nanoparticles, a trend of first increasing and then gradually decreasing was observed for the surface and cross-sectional microstructure of the coating, interpenetration ability of the elements, adhesion performance, and corrosion resistance. The best deposition quality of the coating was obtained when the concentration of SiC nanoparticles was 3 g·L⁻¹. For cross-sectional microstructure, the scratch test revealed that the maximum coating thickness was 17.3 μm, the maximum range of elemental penetration region was 28.39 μm, and the maximum adhesion of the composite coating was 36.5 N. The electrochemical test showed that the composite coating had a −0.30 V self-corrosion potential and 8.45 × 10⁻⁷ A·cm⁻² self-corrosion current density, the slowest corrosion rate. In addition, the composite coating had the best corrosion resistance and the largest impedance arc radius corresponding to an equivalent impedance value R₂ of 3108 Ω. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

9 pages, 44192 KiB

Open AccessArticle

Adhesion of Electrospun Poly(acrylonitrile) Nanofibers on Conductive and Isolating Foil Substrates

by Christian Hellert, Martin Wortmann, Natalie Frese, Georg Grötsch, Carsten Cornelißen and Andrea Ehrmann

Coatings 2021, 11(2), 249; https://doi.org/10.3390/coatings11020249 - 19 Feb 2021

Cited by 11 | Viewed by 2597

Abstract

Electrospinning can be used to prepare nanofibers from various polymers and polymer blends. The adhesion of nanofibers to the substrates on which they are electrospun varies greatly with the substrate material and structure. In some cases, good adhesion is desired to produce sandwich [...] Read more.

Electrospinning can be used to prepare nanofibers from various polymers and polymer blends. The adhesion of nanofibers to the substrates on which they are electrospun varies greatly with the substrate material and structure. In some cases, good adhesion is desired to produce sandwich structures by electrospinning one material directly onto another. This is the case, e.g., with dye-sensitized solar cells (DSSCs). While both pure foil DSSCs and pure electrospun DSSCs have been examined, a combination of both technologies can be used to combine their advantages, e.g., the lateral strength of foils with the large surface-to-volume ratio of electrospun nanofibers. Here, we investigate the morphology and adhesion of electrospun nanofibers on different foil substrates containing materials commonly used in DSSCs, such as graphite, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) or TiO₂. The results show that the foil material strongly influences the adhesion, while a plasma pretreatment of the foils showed no significant effect. Moreover, it is well known that conductive substrates can alter the morphology of nanofiber mats, both at microscopic and macroscopic levels. However, these effects could not be observed in the current study. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

Other

Jump to: Research

14 pages, 3013 KiB

Open AccessPerspective

Recent Report on the Hydrothermal Growth of LiFePO₄ as a Cathode Material

by Dimitra Vernardou

Coatings 2022, 12(10), 1543; https://doi.org/10.3390/coatings12101543 - 14 Oct 2022

Cited by 9 | Viewed by 2868

Abstract

Various growth processes have been utilized for the development of lithium iron phosphate including microwave treatment, spray thermal decomposition, sol-gel and the hydrothermal route. However, microwave treatment, spray process and sol-gel suffer from high costs and difficulties in controlling growth parameters. In this [...] Read more.

Various growth processes have been utilized for the development of lithium iron phosphate including microwave treatment, spray thermal decomposition, sol-gel and the hydrothermal route. However, microwave treatment, spray process and sol-gel suffer from high costs and difficulties in controlling growth parameters. In this review paper, recent synthetic strategies, including the raw materials utilized for the hydrothermal growth of lithium iron phosphate, their effect on the basic characteristics and, as a consequence, the electrochemical performance of cathodes, are reported. The advantages of the hydrothermal process, including high material stability, eco-friendliness, low production costs and material abundance, are explained along with the respective processing parameters, which can be easily tuned to modify lithium iron phosphate characteristics such as structure, morphology and particle size. Specifically, we focus on strategies that were applied in the last three years to improve the performance and electrochemical stability of the cathode utilizing carbon-based materials, N-doped graphene oxide and multi-wall carbon nanotubes (MWCNTs), along with the addition of metallic nanoparticles such as silver. Finally, future perspectives on the hydrothermal process are discussed including the simultaneous growth of powders and solid-state electrodes (i.e., growth of lithium iron phosphate on a rigid substrate) and the improvement in morphology and orientation for its establishment and standardization for the growth of energy storage materials. Full article

(This article belongs to the Special Issue Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Recent Advancement in Thin Film Deposition, Characterization, and Surface Engineering

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Related Special Issue

Published Papers (8 papers)

Research

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI