Ceramic Films and Coatings: Properties and Applications

A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Ceramic Coatings and Engineering Technology".

Deadline for manuscript submissions: closed (30 June 2023) | Viewed by 35735

Special Issue Editor

School of Materials Science and Engineering, Northeastern University, Shenyang, China
Interests: design; syntheses; and application of functional inorganic materials

Special Issue Information

Dear Colleagues,

Various technologies have been developed for ceramic films and coatings since they play an important role in the area of materials science. Compared to bulk ceramics, the preparation of ceramics film is certainly not a tedious process as it includes ball milling, sieving, forming, pre-sintering, and high-temperature sintering. Additionally, it is possible to fabricate ceramic film with various shapes to meet industrial and civil demands. Recently, functional ceramic films and coatings for lighting, anti-counterfeiting, corrosion prevention, wear resistance, and so on, have become a hot research topic. However, films and coatings with high performance still remain a challenge because the preparation technique, composition, microstructure, and compactness significantly affect their properties and final applications.

This Special Issue will cover recent advances in materials synthesis, properties, and applications. In particular, studies on ceramic film, inorganic coatings, and the development of characterization methods are welcome.

It is our pleasure to invite you to submit review articles, original papers, and communications to this Special Issue on “Ceramic Films and Coatings: Properties and Applications”.

Prof. Dr. Qi Zhu
Guest Editor

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Keywords

  • surface coatings
  • ceramic
  • photoluminescence
  • corrosion prevention
  • wear resistance

Published Papers (25 papers)

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Research

15 pages, 5765 KiB  
Article
Preparation of Conductive and Corrosion Resistant Phosphate Conversion Coating on AZ91D Magnesium Alloy
by Shudi Zhang, Yuheng Xu, Linkun Liu, Quanda Lei, Jialin Dong and Tao Zhang
Coatings 2023, 13(10), 1706; https://doi.org/10.3390/coatings13101706 - 28 Sep 2023
Cited by 2 | Viewed by 792
Abstract
The application of magnesium alloys in the 3C industry requires the coexistence of excellent corrosion resistance and good electrical conductivity. In this work, a conductive and corrosion-resistant phosphate conversion coating (PCC) on AZ91D magnesium alloy was investigated. The effects of strong oxidant (KMnO [...] Read more.
The application of magnesium alloys in the 3C industry requires the coexistence of excellent corrosion resistance and good electrical conductivity. In this work, a conductive and corrosion-resistant phosphate conversion coating (PCC) on AZ91D magnesium alloy was investigated. The effects of strong oxidant (KMnO4), additive (Na2MoO4), surface-active agent (OP-10) and their content in phosphating bath on PCCs were studied, and the mechanism of action of strong oxidant was analyzed. The results showed that the optimum content for KmnO4, Na2MoO4 and OP-10 in phosphating bath was 3.0 g/L, 1.5 g/L and 1.0 g/L. The PCC formed at the phosphating bath at the optimum condition was completely covered, the coating on α phases had a bilayer structure and the β phases were protruded. The electrical contact resistance (ECR) of the PCC was as low as 4.91 Ω, the Ecorr positively shifted about 27 mV, and the icorr reduced significantly. The presence of KMnO4 inhibited the formation of phosphate crystals and made the β phases protrude from the surface to form conductive spots, which improved the conductivity of PCCs. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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17 pages, 6052 KiB  
Article
Research on the Corrosion Resistance of an Epoxy Resin-Based Self-Healing Propylene Glycol-Loaded Ethyl Cellulose Microcapsule Coating
by Shudi Zhang, Linkun Liu, Yuheng Xu, Quanda Lei, Jiahui Bing and Tao Zhang
Coatings 2023, 13(9), 1514; https://doi.org/10.3390/coatings13091514 - 27 Aug 2023
Cited by 1 | Viewed by 896
Abstract
In this work, ethyl cellulose was used as a wall material, propanetriol as a core material, polyvinyl alcohol as a stabilizer and gelatin as an emulsifier. Self-healing microcapsules with a slow-release effect were prepared using the solvent evaporation method. Various analytical techniques, such [...] Read more.
In this work, ethyl cellulose was used as a wall material, propanetriol as a core material, polyvinyl alcohol as a stabilizer and gelatin as an emulsifier. Self-healing microcapsules with a slow-release effect were prepared using the solvent evaporation method. Various analytical techniques, such as 3D confocal microscopy (LCSM), optical microscopy (OM), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), energy dispersive spectroscopy (EDS), thermal weight loss analysis (TGA), laser particle size tester and electrochemical impedance polarization, are utilized. The morphology, distribution, particle size, corrosion resistance and self-healing ability of the prepared microcapsules and resin-based coatings were characterized and analyzed. The results show that the cross-sectional core–shell structure is clearly seen in the LCSM, showing a smooth, hollow, spherical shape. OM and laser particle size testers have shown that the size of the microcapsules decreases over time. Also, in OM, the microcapsules are uniformly distributed in the emulsion with a smooth and non-adherent surface. In SEM, the microcapsule particle size is about 150 μm, the shell wall thickness is about 18 μm, and the hollow structure of ruptured microcapsules is obvious. FT-IR and TGA confirmed the successful encapsulation of the formulated microcapsules. The results show that when the core-wall mass ratio is 1.2:1 and the amount of microcapsule is 10% of the coating amount, the prepared microcapsule has high thermal stability and certain wear resistance. By electrochemical and immersion experiments, it was found that a 3.5 wt % NaCl solution has the best impedance, the lowest corrosion current density, and good adhesion and tensile toughness. The results showed that glycerol was successfully released from the broken microcapsules and self-healed, forming an anticorrosive coating with excellent corrosion resistance and self-healing ability. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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19 pages, 6882 KiB  
Article
Investigation of Structural and Tribological Characteristics of TiN Composite Ceramic Coatings with Pb Additives
by Aleksandr Lozovan, Svetlana Savushkina, Maksim Lyakhovetsky, Ilya Nikolaev, Sergey Betsofen and Ekaterina Kubatina
Coatings 2023, 13(8), 1463; https://doi.org/10.3390/coatings13081463 - 20 Aug 2023
Viewed by 707
Abstract
Solid lubricating composite TiN coatings with Pb additives were obtained on steel and titanium substrates in the process of reactive magnetron sputtering of separate cathodes. Columnar, columnar nanostructured and composite nanostructured TiN coatings with different contents (3–13%) of a lubricating component (Pb) were [...] Read more.
Solid lubricating composite TiN coatings with Pb additives were obtained on steel and titanium substrates in the process of reactive magnetron sputtering of separate cathodes. Columnar, columnar nanostructured and composite nanostructured TiN coatings with different contents (3–13%) of a lubricating component (Pb) were obtained by deposition onto rotating and stationary substrates. It was found that deposition at a rotating substrate and 3% Pb content in the TiN matrix led to a columnar crystallite coating structure. With an increase in its content to 8%, columnar crystallites in the structure become less pronounced, and the coating becomes columnar nanostructured. In nanostructured composite coating with 12% Pb, the soft component is distributed both in the matrix and in the form of inclusions. XRD analysis of the composite nanostructured TiN–Pb coating indicates a textureless state. In this case, the diffraction lines of all present phases (Pb, PbO, TiN) are characterized by a significant broadening, indicating that the size of the subgrains are in range of 10–20 nm. Tribological tests of the coatings were carried out at room temperature and under conditions of stepwise heating. The nanostructured composite coating showed the best tribological characteristics due to a high Pb content, a relatively high microhardness (817 HV) and a textureless state with a low grain size. This coating had a low friction coefficient (~0.1) over 50,000 test cycles, both at room temperature and under conditions of stepwise heating up to 100 °C and 200 °C. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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12 pages, 7748 KiB  
Article
Sunlight-Activated Long Persistent Luminescent Coating for Smart Highways
by Mao Zheng, Xin Li, Yu Bai, Shijun Tang, Peiyang Li and Qi Zhu
Coatings 2023, 13(6), 1050; https://doi.org/10.3390/coatings13061050 - 06 Jun 2023
Cited by 1 | Viewed by 1216
Abstract
With the whole society’s demand for intelligence, the smart highway has become the inevitable trend of road development. Luminescent road marking made of long persistent luminescent coating is a new type of functional marking that is designed with long afterglow luminescent material as [...] Read more.
With the whole society’s demand for intelligence, the smart highway has become the inevitable trend of road development. Luminescent road marking made of long persistent luminescent coating is a new type of functional marking that is designed with long afterglow luminescent material as the raw material and has many features such as safety, beauty and energy saving. Here, SrA12O4:Eu2+,Dy3+ green long afterglow phosphors were prepared using a high-temperature solid state method. The green phosphors obtained at 1350 °C have two traps with a shallow trap depth of 0.66 eV and a deep trap depth of 0.8 eV. The green afterglow can be seen in the dark for more than 8 h after sunlight excitation for 2 h. The green long persistent luminescent coatings were synthesized using the blending method. The uniformity of each component can be improved by adding 1.25% SiO2 into the luminescent coatings. The addition of 3.5% CaCO3 will improve the compactness of the coatings and reduce water absorption. After soaking in water for 120 h, the afterglow intensity of the coating decreases to 76% of the original, showing good water resistance. After daylight excitation in different weather conditions (cloudy, sunny, rainy), the afterglow can reach more than 5 h; therefore, it can be applied to a smart highway. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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12 pages, 3738 KiB  
Article
Mechanical Properties and Wear Resistance of CrSiN Coating Fabricated by Magnetron Sputtering on W18Cr4V Steel
by Changqing Cui and Chunyan Yang
Coatings 2023, 13(5), 889; https://doi.org/10.3390/coatings13050889 - 09 May 2023
Cited by 4 | Viewed by 1257
Abstract
To increase the service life of tool materials and further meet the demands of modern high-speed machining, a Si-doping CrN coating consisting of Si3N4 amorphous and CrN nanocrystalline was fabricated on top of W18Cr4V high-speed steel. The effect of coating [...] Read more.
To increase the service life of tool materials and further meet the demands of modern high-speed machining, a Si-doping CrN coating consisting of Si3N4 amorphous and CrN nanocrystalline was fabricated on top of W18Cr4V high-speed steel. The effect of coating thickness on its structure and properties was investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), scratch test, nano-indenter, and friction–abrasion tester. The thickness of the coating was modulated by the deposition time. The results show that the coating consists of a CrN phase distributed into an amorphous Si3N4 matrix. As the thickness increased, the surface defects decreased, and the residual compressive stress, hardness, and elastic modulus as well as the H/E and H3/E2 factors increased, improving the wear resistance significantly. The adhesion between coating and substrate increased first and then decreased, and it reached the maximum when the coating thickness was 1.9 μm (deposition 60 min). Moreover, the effect of toughness on wear resistance and the wear mechanisms is discussed. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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17 pages, 5968 KiB  
Article
Characteristics and Cutting Performance of CVD Al2O3 Multilayer Coatings Deposited on Tungsten Carbide Cutting Inserts in Turning of 24CrMoV5-1 Steel
by Maoxiang Zhu, Soufyane Achache, Mariane Prado Motta, Alexandre Delblouwe, Cyril Pelaingre, Alexis Carlos García-Wong, Jean-François Pierson and Frédéric Sanchette
Coatings 2023, 13(5), 883; https://doi.org/10.3390/coatings13050883 - 08 May 2023
Viewed by 953
Abstract
In this work, TiN/Ti(C,N)/Al2O3 multilayer coatings were deposited using an industrial-scale thermal CVD system. Two polymorphs of Al2O3, the stable α- and the metastable κ-Al2O3, were obtained by the deposition of specific [...] Read more.
In this work, TiN/Ti(C,N)/Al2O3 multilayer coatings were deposited using an industrial-scale thermal CVD system. Two polymorphs of Al2O3, the stable α- and the metastable κ-Al2O3, were obtained by the deposition of specific bonding layers at the Al2O3/Ti(C,N) interface. The comparable hardness and elastic moduli of α- and κ-Al2O3 multilayer coatings were measured. The tribological behavior of Al2O3 multilayer coatings was studied at room temperature using 24CrMoV5-1 balls; friction coefficients were comparable for both α- and κ-Al2O3 multilayer coatings. As a result of the relatively high hardness of coatings and the generation of abrasive wear particles, larger wear tracks were observed on balls. In Rockwell C tests, good adhesion at Al2O3/Ti(C,N)-based layer’s interface was reported in κ-Al2O3 multilayer coatings, which could be attributed to the deposition of κ-bonding layers consisting of needle-shaped grains. The cutting performances in the turning-roughing of 24CrMoV5-1 steel under different parameters—cutting speed, feed, and depth of cut—were investigated. Herein, κ-Al2O3 multilayer coatings showed the longest tool life, double of that of a commercial CVD Al2O3 multilayer coating. The results obtained could enrich the existing database for the development of prediction models of tool wear and machined surface quality and help improve tool performance for the machining of 24CrMoV5-1 steel. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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13 pages, 6576 KiB  
Article
Enhanced Performance in Si3N4 Ceramics Cutting Tool Materials by Tailoring of Phase Composition and Hot-Pressing Temperature
by Shuai Guo, Fusheng Zhu, Zhimeng Xiu, Mu Zhang and Xudong Sun
Coatings 2023, 13(2), 475; https://doi.org/10.3390/coatings13020475 - 20 Feb 2023
Cited by 3 | Viewed by 1583
Abstract
In this study, a type of micro-nano Si3N4 matrix ceramic cutting tool material was successfully prepared by controlling the addition amount of TiC0.7N0.3 and the hot-pressing sintering temperature. The effects of different volume fractions of TiC0.7 [...] Read more.
In this study, a type of micro-nano Si3N4 matrix ceramic cutting tool material was successfully prepared by controlling the addition amount of TiC0.7N0.3 and the hot-pressing sintering temperature. The effects of different volume fractions of TiC0.7N0.3 on the microstructure, mechanical properties, particle size distribution, and relative density of Si3N4 ceramic tools at the same temperature were investigated. The results show that the addition of TiC0.7N0.3 makes the β-Si3N4 grains with different diameters and aspect ratios interlaced and tightly bonded, thus achieving the strengthening and toughening effects. In addition, the effects of different hot-press sintering temperatures on the properties of Si3N4 ceramic tool materials were studied. It was concluded that the density of the material increased with the increase of the hot-pressing temperature. The relative density, flexural strength, and fracture toughness of the samples with 1 vol% TiC0.7N0.3 added at 1750 °C and 30 MPa pressure reached 99.22%, 993 MPa, and 9.81 MPa·m1/2, respectively. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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15 pages, 15694 KiB  
Article
Novel Method for Deposition of Gas-Tight SiC Coatings
by Sergey Shikunov, Alexei Kaledin, Irina Shikunova, Boris Straumal and Vladimir Kurlov
Coatings 2023, 13(2), 354; https://doi.org/10.3390/coatings13020354 - 03 Feb 2023
Cited by 2 | Viewed by 1619
Abstract
A new high-temperature method for the deposition of gas-tight silicon carbide protective coatings with low gas permeability has been developed. The free carbon atoms form during the high-temperature pyrolysis of hydrocarbon molecules. In turn, carbon reacts with molten silicon contained in the subsurface [...] Read more.
A new high-temperature method for the deposition of gas-tight silicon carbide protective coatings with low gas permeability has been developed. The free carbon atoms form during the high-temperature pyrolysis of hydrocarbon molecules. In turn, carbon reacts with molten silicon contained in the subsurface substrate layers and/or with silicon vapor. The source of silicon vapor serves the molten silicon in the heated zone of a reactor furnace. Such coatings effectively protect SiC-C-Si and SiC-C-MoSi2 ceramics, carbon–carbon composite materials, structural graphite, and refractory metals and alloys from oxidation. The conducted tests show the high thermal oxidation and thermal shock stability of deposited protective coatings, as well as their good adhesion to the substrates. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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12 pages, 4233 KiB  
Article
Glass-Ceramic Protective Coatings Based on Metallurgical Slag
by Alexander V. Gorokhovsky, Gleb Yu. Yurkov, Igor N. Burmistrov, Angel F. Villalpando-Reyna, Denis V. Kuznetsov, Alexander A. Gusev, Bekzod B. Khaidarov, Yuri V. Konyukhov, Olga V. Zakharova and Nikolay V. Kiselev
Coatings 2023, 13(2), 269; https://doi.org/10.3390/coatings13020269 - 24 Jan 2023
Cited by 1 | Viewed by 2108
Abstract
Pyroxene glass-ceramic enamels based on combinations of blast furnace slag and some additives were produced and investigated. The batch compositions and technological regimes of enameling were developed to produce high temperature protective coatings for carbon steel (ASTM 1010/1008). The composition of raw materials [...] Read more.
Pyroxene glass-ceramic enamels based on combinations of blast furnace slag and some additives were produced and investigated. The batch compositions and technological regimes of enameling were developed to produce high temperature protective coatings for carbon steel (ASTM 1010/1008). The composition of raw materials was selected to match the values of the thermal expansion coefficients of the glass-ceramic coating (~11∙10−6 K−1) and metal substrate (~12∙10−6 K−1) taking into account the temperatures of fluidization (Tf ~ 800°) and crystallization (Tc = 850−1020 °C) of the corresponding glasses. The covered and thermally treated samples of carbon steel were produced using single-layer enameling technology and investigated to specify structure, phase composition and properties of the coating and coating-steel interface. The obtained coatings were characterized with excellent adhesion to the steel (impact energy ~3 J) and protective properties. The closed porous structure of the coatings promoted low thermal conductivity (~1 W/(m·K)) and high (up to 1000 °C) thermal resistance, whereas the pyroxene-like crystalline phases supported high wear and chemical resistance as well as micro-hardness (~480 MPa) and thermal shock resistance (>30 cycles of 23–700 °C). The obtained cheap coatings and effective protective coatings could be used at the temperatures up to 1100 °C in the corrosive atmosphere and under the action of abrasive particles. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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19 pages, 15542 KiB  
Article
Ultrasonic-Induced Grain Refinement in Laser Cladding Nickel-Based Superalloy Reinforced by WC Particles
by Jizhuang Wang, Jianzhong Zhou, Teng Zhang, Xiankai Meng, Pengfei Li, Shu Huang and Hao Zhu
Coatings 2023, 13(1), 151; https://doi.org/10.3390/coatings13010151 - 11 Jan 2023
Cited by 8 | Viewed by 1440
Abstract
Laser cladding was used to prepare three composite coatings, i.e., Inconel 718 nickel-based superalloy (IN718), IN718-50 wt.% WC created by adding tungsten carbide (WC) particles and IN718-50 wt.% WC assisted by ultrasonic vibration. The phase composition, microstructure evolution, microhardness, residual stress and tribological [...] Read more.
Laser cladding was used to prepare three composite coatings, i.e., Inconel 718 nickel-based superalloy (IN718), IN718-50 wt.% WC created by adding tungsten carbide (WC) particles and IN718-50 wt.% WC assisted by ultrasonic vibration. The phase composition, microstructure evolution, microhardness, residual stress and tribological properties of the three coatings were studied. The addition of WC enhances hardness and improves tribological properties, but also causes aggregation and considerable formation of carbides associated with rough structure. Ultrasonic vibration greatly refines the solidification microstructure, as it can break the growing dendrites, reduce the aggregation of reinforced particles and refine solidified structure. The average microhardness of the latter two composite coatings was increased by 36.37% and 57.15%, respectively, compared with the first IN718 coating, and the last composite coating (ultrasonic assistance) had the lowest COF (0.494). The WC particles and refined carbides converted the wear mechanism from adhesive wear to abrasive wear. In addition, the resultant stress on the surface of the composite coating roughly doubled after adding 50 wt.% WC, and only increased by 49.53% with ultrasonic treatment. The simulation results indicate that acoustic cavitation mainly occurs in the middle and bottom of the molten pool and proper frequency ultrasonic is conducive to the generation of the cavitation effect. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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15 pages, 6930 KiB  
Article
Microstructure Evolution and Hardness Improvement of WC-Co Composites Sintered with Fe Substituting Part of Co Binder
by Xun Li, Junfei Zhang, Qiang Zhang, Xianwei Zhang, Vincent Ji and Jinlong Liu
Coatings 2023, 13(1), 116; https://doi.org/10.3390/coatings13010116 - 08 Jan 2023
Cited by 1 | Viewed by 1586
Abstract
WC-13Co (wt.%) composite with Fe added was prepared by pressureless sintering, and its microstructure and mechanical properties were analyzed by X-ray Diffraction (XRD), Scanning Electronic Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Vickers hardness tester. The effect of Fe and C content on [...] Read more.
WC-13Co (wt.%) composite with Fe added was prepared by pressureless sintering, and its microstructure and mechanical properties were analyzed by X-ray Diffraction (XRD), Scanning Electronic Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Vickers hardness tester. The effect of Fe and C content on the microstructure of the eta phase, binder phase, grain size and porosity, as well as mechanical properties in the W-Co-Fe-C system, was discussed quantitatively. The position of added Fe in the lattice of the composites is clarified. When 2%–4% Fe was added, Fe existes in both the binder phase and the low-carbon eta phase. In the lattice of the eta phase, Fe occupies the position of Co and Fe uniformly existes in the binder with the structure of simple cubic when the composites is in the eutectic phase region. Differently from the previous report that the growth of WC in liquid Fe was severely limited, the size of WC in the W-Co-Fe-C system increases from 1.14 μm to 1.21 μm when the content of Fe increases from 0 to 4%, which indicates that the growth behavior of WC in liquid CoFe was different from that in liquid Fe, but closer to that in liquid Co. The sample added both 2% Fe and 1% C has the optimum matching of hardness and toughness. Compared with the hardness of 979 HV30 in the sample without adding Fe and C, the hardness of the sample with both 2% Fe and 1% C added achieved 1071 HV30, which is increased by 9.4% under the conditions of a slight increase in fracture toughness. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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11 pages, 3033 KiB  
Article
Influence of the Nitrogen Flux Ratio on the Structural, Morphological and Tribological Properties of TiN Coatings
by Xiaojing Fu, Shuming Guo, Yong Wan, Qiang Li, Bingchang Liu and Hui Zheng
Coatings 2023, 13(1), 78; https://doi.org/10.3390/coatings13010078 - 31 Dec 2022
Cited by 10 | Viewed by 1546
Abstract
In this study, the structural characteristics of TiN coatings deposited by DC magnetron sputtering on the surface of AISI 304 stainless steel were modulated by performing deposition at four different nitrogen flux ratios. The XRD results indicated that the coatings mainly contained face-centered [...] Read more.
In this study, the structural characteristics of TiN coatings deposited by DC magnetron sputtering on the surface of AISI 304 stainless steel were modulated by performing deposition at four different nitrogen flux ratios. The XRD results indicated that the coatings mainly contained face-centered cubic TiN phase. The experimental results showed that the nitrogen flux ratio played a major role in determining the microstructure and the mechanical and tribological properties of the TiN coatings. SEM images revealed that the thickness of the TiN coatings decreased linearly as the nitrogen flux ratio increased from 0.25 to 0.55. However, the grain size had a nonlinear relationship with the nitrogen flux ratio. When the nitrogen flux ratio was 0.45, the grain size was only 5.3 nm. Theoretical and experimental analysis showed that the TiN coating deposited at a nitrogen flux ratio of 0.45 had the best mechanical properties, which due to its minimum grain size and (111) orientation, and the best tribological performance under unlubricated conditions, may have been due to its higher fracture toughness and plastic deformation resistance among the four TiN coatings. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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12 pages, 5196 KiB  
Article
Effect of Mo and C Additions on Eta Phase Evolution of WC-13Co Cemented Carbides
by Xun Li, Xianwei Zhang, Junfei Zhang, Qiang Zhang, Vincent Ji and Jinlong Liu
Coatings 2022, 12(12), 1993; https://doi.org/10.3390/coatings12121993 - 19 Dec 2022
Cited by 3 | Viewed by 1596
Abstract
The WC-13Co (wt.%) cemented carbide was prepared by simple pressureless sintering, and the influence of Mo and C additions on the eta evolution and mechanical properties was analyzed by XRD, SEM, EDS, XPS, and Vickers hardness tester. The results show that the addition [...] Read more.
The WC-13Co (wt.%) cemented carbide was prepared by simple pressureless sintering, and the influence of Mo and C additions on the eta evolution and mechanical properties was analyzed by XRD, SEM, EDS, XPS, and Vickers hardness tester. The results show that the addition of Mo has an important influence on the composition, size, and distribution of the eta phase and Mo2C phase. When the Mo content increases from 0 to 2.5%, the Mo-enriched eta phase grows abnormally and the area fraction of the eta phase significantly increases to 40%, leading to an obvious increase in hardness from 1232 HV30 to 1321 HV30, and a decrease in fracture toughness from 12.5 MPa·m1/2 to 9.8 MPa·m1/2. The addition of carbon black effectively inhibits the formation of the eta phase in the samples with 2.5% Mo. Moreover, adding Mo can suppress WC coarsening in a high-carbon content, which is different from the obvious growth of WC grains in a high-carbon environment in traditional research. Finally, the mechanism of eta phase evolution during the sintering process of WC-Co cemented carbides containing Mo is discussed systematically. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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11 pages, 3667 KiB  
Article
A Two-Dimensional Guidance Strategy to Fabricate Perovskite Gadolinium Aluminate Ceramic Film
by Tao Zhang, Lu Chen, Jing Yao and Qi Zhu
Coatings 2022, 12(12), 1927; https://doi.org/10.3390/coatings12121927 - 08 Dec 2022
Viewed by 1324
Abstract
Gadolinium aluminate is an effective host for doping with various ions, and it can emit various colors. However, it is not easy to prepare transparent ceramics of gadolinium aluminate using traditional methods, although transparent ceramics are very suitable for solid lighting. In this [...] Read more.
Gadolinium aluminate is an effective host for doping with various ions, and it can emit various colors. However, it is not easy to prepare transparent ceramics of gadolinium aluminate using traditional methods, although transparent ceramics are very suitable for solid lighting. In this work, a two-dimensional guidance strategy has been successfully carried out for perovskite-structured aluminate ceramic film. Through the two-dimensional interfacial reaction, GdAlO3:Eu3+ (GAP:Eu3+) transparent ceramic films were successfully fabricated using nanosheets exfoliated from layered gadolinium hydroxide, a rare earth source. The final films were tested by characterization techniques, including XRD, SEM, TEM, FT-IR, PLE/PL spectroscopy, temperature-dependent PL spectroscopy, and luminescence decay analysis. The perovskite film of transparent ceramics can be obtained by calcining LRH nanosheets on the substrate of amorphous alumina at 1550 °C in air with a reaction time of 2 h. During the interface reaction, temperature-dependent element diffusion takes the dominant role, and increased reactants take in the reaction with increasing calcination temperature. The grain for ceramic film is only 2–5 μm, which is much smaller than that for bulk ceramic. This is mainly due to the lower temperature and the interface diffusion. Ceramic film has a high transmittance larger than 90% at the visible range. Upon UV excitation at 254 nm, the film exhibits intense emission at the red wavelength range. The outcomes described in this work may have wide implications for transparent ceramics and layered rare-earth hydroxides. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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13 pages, 4047 KiB  
Article
Effect of Polyaniline and Graphene Oxide Composite Powders on the Protective Performance of Epoxy Coatings on Magnesium Alloy Surfaces
by Yingjun Zhang, Shuai Xiao, Jie Wen, Xinyu Liu, Baojie Dou and Liu Yang
Coatings 2022, 12(12), 1849; https://doi.org/10.3390/coatings12121849 - 29 Nov 2022
Cited by 1 | Viewed by 1047
Abstract
Composite fillers are often used to improve the protective properties of coatings. To obtain a high protective performance of epoxy coatings for magnesium alloys, polyaniline (PANI) and graphene oxide (GO) composite powders were selected because of their corrosion inhibition and barrier performance, respectively. [...] Read more.
Composite fillers are often used to improve the protective properties of coatings. To obtain a high protective performance of epoxy coatings for magnesium alloys, polyaniline (PANI) and graphene oxide (GO) composite powders were selected because of their corrosion inhibition and barrier performance, respectively. The paper mainly focuses on the effect of the preparation methods of the composite powders on the protective performance. PANI and GO composite powders were prepared by in situ polymerization and blending, respectively. First, the composite powder was characterized by X-ray diffractometer, Fourier transform infrared spectroscopy, and scanning electron microscopy. Then, the different composite powders and pure PANI powder were dispersed uniformly in epoxy resin, and the coating was prepared on the surface of the AZ91D magnesium alloy and studied by an electrochemical impedance test, adhesion strength test and physical properties test. The results show that the impedance value of the coating with the added PANI and GO composite powders by in situ polymerization was 4 × 109 Ω·cm2 and higher than that with the added pure PANI (4 × 109 Ω·cm2) and PANI and GO mixed powders (1 × 109 Ω·cm2) after 2400 h immersion in a 3.5% NaCl solution; the former also had better flexibility, ss impact resistance, and adhesion strength. Compared with the direct blending method, the PANI and GO polymerization powders can exert the shielding effect of GO and PANI corrosion inhibition better and achieve a better protective effect on the magnesium alloy. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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15 pages, 6380 KiB  
Article
Micro-Structural Design of CoFe2O4/SWCNTs Composites for Enhanced Electromagnetic Properties
by Zaoxia Hou, Chenyang Liu, Jialuo Gong, Junjie Wu, Shuchen Sun, Mu Zhang and Xudong Sun
Coatings 2022, 12(10), 1532; https://doi.org/10.3390/coatings12101532 - 13 Oct 2022
Cited by 5 | Viewed by 1386
Abstract
In order to prepare microwave-absorbing materials with low density and high wave absorption performance, CoFe2O4/SWCNTs composites with well-designed necklace-like structures were successfully prepared in this paper by a simple solvothermal method. CoFe2O4/SWCNTs composites with different [...] Read more.
In order to prepare microwave-absorbing materials with low density and high wave absorption performance, CoFe2O4/SWCNTs composites with well-designed necklace-like structures were successfully prepared in this paper by a simple solvothermal method. CoFe2O4/SWCNTs composites with different cobalt salt contents were synthesized by adjusting the experimental parameters. The results of the relative complex permeability and relative permittivity of the samples, which were investigated by vector network analysis in the frequency range of 2 to 18 GHz, are collected to support the study of the microwave absorption characteristics of the samples. Different microsphere densities and different cobalt salt contents have obvious differences in the electromagnetic absorption properties of the composites. When the additions of FeCl3·6H2O, Co(Ac)2·4H2O, and NH4Ac were 0.432, 0.200, and 0.400 g, respectively, the best reflection loss reached −42.07 dB, and the effective absorption frequency (RL < −10 dB) ranges from 3.2 to 18 GHz. Therefore, this is a preparation strategy of CoFe2O4/SWCNTs composites with necklace structure, which has the advantages of simple process, environmental friendliness, low cost, and high stability. The unique necklace-like structure design makes the carbon nanotubes partially exposed, which is more beneficial to achieve good impedance matching and giving the CoFe2O4/SWCNTs composite excellent electromagnetic loss capability. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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11 pages, 2042 KiB  
Article
Synthesis of MgO Coating Gd2O3 Nanopowders for Consolidating Gd2O3-MgO Nanocomposite with Homogenous Phase Domain Distribution and High Mid-Infrared Transparency
by Nan Wu, Zhongchao Fu, Haibo Long, Jianming Wang, Jun Zhang, Zhaoxia Hou, Xiaodong Li and Xudong Sun
Coatings 2022, 12(10), 1435; https://doi.org/10.3390/coatings12101435 - 29 Sep 2022
Cited by 3 | Viewed by 1177
Abstract
Improved optical and mechanical properties are required for future infrared windows working in harsher mechanical and thermal environments than today. Ameliorating the homogeneity of the phase domain and reducing the size of the phase domain are effective approaches for enhancing the optical transmittance [...] Read more.
Improved optical and mechanical properties are required for future infrared windows working in harsher mechanical and thermal environments than today. Ameliorating the homogeneity of the phase domain and reducing the size of the phase domain are effective approaches for enhancing the optical transmittance and mechanical hardness of a nanocomposite. In this work, we reported that the Gd2O3-MgO nanopowders were prepared by two different processes. The core–shell nanopowders synthesized by urea precipitation have a much lower agglomeration than the nanopowders prepared by sol–gel. Excellent transmittance (70.0%–84.1%) at 3–6 μm mid-infrared wave range and a high Vickers hardness value (10.3 ± 0.6 GPa) were maintained using the nanopowders synthesized by urea precipitation mainly due to its homogenous phase domain distribution. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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11 pages, 4465 KiB  
Article
Rational Design of Yolk Core-Shell Structure MnO-Co@C Nanospheres for High-Performance Microwave Absorption
by Zhen Xin, Junjie Wu, Shuchen Sun, Mu Zhang and Xudong Sun
Coatings 2022, 12(10), 1405; https://doi.org/10.3390/coatings12101405 - 27 Sep 2022
Cited by 2 | Viewed by 1182
Abstract
MnO-Co@C nanospheres were fabricated by in situ polymerizing and high-temperature carbonizing processes. This unique synthesis method does not require any template or reducing gas. The synthesized multicore-shell structure has a shell of about 500 nm and multiple nuclei of several tens of nanometers. [...] Read more.
MnO-Co@C nanospheres were fabricated by in situ polymerizing and high-temperature carbonizing processes. This unique synthesis method does not require any template or reducing gas. The synthesized multicore-shell structure has a shell of about 500 nm and multiple nuclei of several tens of nanometers. Subsequently, extensive experiments were conducted to adjust the material composition of the nanospheres by adjusting the amount of resorcinol and formaldehyde. The results showed that the obtained material performed best when resorcinol and formaldehyde were added to 0.2 g MnCo2O4 at 0.3 g and 0.42 mL, respectively. The efficient absorption bandwidth (EAB) value reaches 3.3 GHz when the absorber thickness is 3 mm. The reflection loss (RL) is up to −23.8 dB when the frequency is at 8.6 GHz. The unique yolk core-shell structure gives the material a heterogeneous interface, and the enhanced interfacial polarization loss causes the enhanced dielectric loss. The carbon layer with microporosity also causes conduction loss and multiple reflections. The composite structure formed by metallic Co, MnO, and carbon has better impedance matching and improved microwave absorption capability. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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15 pages, 37673 KiB  
Article
Effect of Si3N4/TaC Particles on the Structure and Properties of Microarc Oxidation Coatings on TC4 Alloy
by Wei Gao, Liqun Wang, Yaohua Jin, Yuhong Yao, Zhisong Ding, Wei Yang and Jiangnan Liu
Coatings 2022, 12(9), 1247; https://doi.org/10.3390/coatings12091247 - 26 Aug 2022
Cited by 1 | Viewed by 1374
Abstract
Si3N4/TaC composite MAO coatings were fabricated by microarc oxidation (MAO) on a Ti–6Al–4V (TC4) alloy in a phosphate-based electrolyte containing Si3N4/TaC mixed particles. The influence of the amount of Si3N4/TaC particles [...] Read more.
Si3N4/TaC composite MAO coatings were fabricated by microarc oxidation (MAO) on a Ti–6Al–4V (TC4) alloy in a phosphate-based electrolyte containing Si3N4/TaC mixed particles. The influence of the amount of Si3N4/TaC particles on the microstructure, composition, tribological behavior, and corrosion properties of the MAO coatings has been investigated. Morphological research of the MAO coatings was carried out using scanning electron microscopy (SEM), with the surface porosity analyzed by ImageJ software. X-ray diffraction (XRD) was used for the detection of the phase characteristic of the MAO coatings, and an abrasive wear test and electrochemical measurements were conducted in the artificial seawater solution by the ball-on-disc friction tester and the electrochemical workstation, respectively. The results showed that Si3N4/TaC particles could be successfully incorporated into the composite coatings, and the addition of Si3N4/TaC particles greatly reduced the porosity of the coatings, thus improving both tribological and corrosion properties of the composite MAO coatings. The composite MAO coating with the addition of 1 g/L Si3N4 + 0.5 g/L TaC particles showed the best tribological property and the optimum corrosion properties. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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14 pages, 4602 KiB  
Article
Incorporation of Mg2+/Si4+ in ZnGa2O4:Cr3+ to Generate Remarkably Improved Near-Infrared Persistent Luminescence
by Shimeng Zhang, Junqing Xiahou, Xudong Sun and Qi Zhu
Coatings 2022, 12(9), 1239; https://doi.org/10.3390/coatings12091239 - 25 Aug 2022
Cited by 2 | Viewed by 1603
Abstract
Near-infrared emitting nano-sized particles of ZnGa2−x(Mg/Si)xO4:Cr3+ (x = 0–0.15, termed as ZGMSO:Cr3+) with persistent luminescence were prepared by sol-gel processing followed by calcination. The samples were tested by XRD, TEM, STEM, SAED, [...] Read more.
Near-infrared emitting nano-sized particles of ZnGa2−x(Mg/Si)xO4:Cr3+ (x = 0–0.15, termed as ZGMSO:Cr3+) with persistent luminescence were prepared by sol-gel processing followed by calcination. The samples were tested by XRD, TEM, STEM, SAED, Raman, XPS, UV-Vis-NIR, TL, PLE/PL spectroscopy, and persistent luminescence decay analysis. Equimolar incorporation of Mg2+ and Si4+ ions did not change the spindle structure of ZnGa2O4 seriously. Most Mg2+ ions are more likely to occupy the sites in octahedron, but Si4+ ions are more likely to occupy the sites in tetrahedron in priority. A broader bandgap, up shift of conduction band minimum, and more anti-defects were found at a higher Mg2+/Si4+ doping concentration. ZGMSO:Cr3+ outputs near-infrared emission with a dominated band at 694 nm (2E → 4A2 transition of Cr3+), which can last longer than 48 h after the stoppage of UV irradiation. Mg2+/Si4+ doping contributes to a better near-infrared persistent luminescence, and the strongest and the longest NIR afterglow was observed at x = 0.05, owing to that the x = 0.05 sample has the deepest defects. The synthesized nanoparticles of ZGMSO:Cr3+ not only output intense NIR afterglow but also can be recharged by the red light of LED several times, indicating that they are the potential nano probes for bio imaging in living animals. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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15 pages, 31206 KiB  
Article
Fabrication of Yb:YAG Transparent Ceramic by Vacuum Sintering Using Monodispersed Spherical Y2O3 and Al2O3 Powders
by Jinsheng Li, Xin Liu, Lei Wu, Haipeng Ji, Liang Dong, Xudong Sun and Xiwei Qi
Coatings 2022, 12(8), 1155; https://doi.org/10.3390/coatings12081155 - 10 Aug 2022
Cited by 3 | Viewed by 1974
Abstract
In the present work, Yb:YAG (yttrium aluminum garnet) transparent ceramics were fabricated using monodispersed spherical Y2O3, Al2O3 powders and commercial Yb2O3 nano-powder as raw materials, adding 0.5 wt% tetraethyl orthosilicae (TEOS) through the [...] Read more.
In the present work, Yb:YAG (yttrium aluminum garnet) transparent ceramics were fabricated using monodispersed spherical Y2O3, Al2O3 powders and commercial Yb2O3 nano-powder as raw materials, adding 0.5 wt% tetraethyl orthosilicae (TEOS) through the solid-state method and vacuum sintering technology. The prepared monodispersed Y2O3 and Al2O3 powders adopted by homogeneous co-precipitation showed improved mixing uniformity and lead to the reduced defect of the YAG powders. After sintering in vacuum at 1700 °C for 10 h, the (Y1−xYbx)AG (x = 0, 0.01, 0.10) ceramics with high transparency were obtained. Analysis of the densification rate, micromorphology, and optical properties of the ceramics suggests that the performance of the Yb:YAG ceramics is independent of the doping amount of Yb. Moreover, when the Y2O3, Al2O3, and Yb2O3 mixtures were laid aside for some time in the air after milling and drying, the performances of the as-prepared Yb:YAG ceramics would be affected distinctively. It is likely because the Y2O3 is easily hydrolyzed to Y(OH)3, Y(OH)2+ and Y2(OH)24+, which impinged the sintering activity of the powder mixture. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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10 pages, 5839 KiB  
Article
Fabrication of Highly Transparent Y2O3 Ceramics via Colloidal Processing Using ZrO2-Coated Y2O3 Nanoparticles
by Zhongchao Fu, Nan Wu, Haibo Long, Jianming Wang, Jun Zhang, Zhaoxia Hou, Xiaodong Li and Xudong Sun
Coatings 2022, 12(8), 1077; https://doi.org/10.3390/coatings12081077 - 30 Jul 2022
Cited by 2 | Viewed by 1568
Abstract
An easy approach is described for the preparation of ZrO2-coated Y2O3 nanopowder from a solution of zirconium nitrate with commercial Y2O3 nanopowder. The evolution process of the ZrO2 coating layer upon calcination, such as [...] Read more.
An easy approach is described for the preparation of ZrO2-coated Y2O3 nanopowder from a solution of zirconium nitrate with commercial Y2O3 nanopowder. The evolution process of the ZrO2 coating layer upon calcination, such as the phase and microstructure of the particles’ surface, was studied. Calcination of the powder at 700 °C resulted in ZrO2-coated Y2O3 nanopowder. The rheological properties of the suspensions of ZrO2-coated Y2O3 powders were studied. A well-dispersed suspension with a solid loading of 35.0 vol% using ZrO2-coated Y2O3 nanopowder was obtained. The consolidated green body obtained by the centrifugal casting method showed improved homogeneity with a relative density of 50.2%. Transparent ceramic with high transparency and an average grain size of 1.7 µm was obtained by presintering at 1500 °C for 16 h in air, followed by post-HIP at 1550 °C for 2 h under 200 MPa pressure. The in-line transmittance at the wavelength of 1100 nm (1.0 mm thick) reached 81.4%, close to the theoretical transmittance of Y2O3 crystal. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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20 pages, 15533 KiB  
Article
Comparison of Microstructure, Microhardness, Fracture Toughness, and Abrasive Wear of WC-17Co Coatings Formed in Various Spraying Ways
by Xiao Chen, Chengdi Li, Qinqin Gao, Xixi Duan and Hao Liu
Coatings 2022, 12(6), 814; https://doi.org/10.3390/coatings12060814 - 10 Jun 2022
Cited by 8 | Viewed by 1516
Abstract
WC-Co cermet materials serving as protective coatings are widely used in many fields. Conventional WC-17Co coatings were formed in high-velocity oxygen-fuel (HVOF), warm spraying (WS), and cold spraying (CS), respectively. Deposition behavior of a single WC-17Co particle, as well as the microstructure, microhardness, [...] Read more.
WC-Co cermet materials serving as protective coatings are widely used in many fields. Conventional WC-17Co coatings were formed in high-velocity oxygen-fuel (HVOF), warm spraying (WS), and cold spraying (CS), respectively. Deposition behavior of a single WC-17Co particle, as well as the microstructure, microhardness, fracture toughness, and abrasive wear of WC-17Co coatings formed in various spraying ways were investigated. The results show that the deposition behavior of a single WC-17Co particle was different after it was deposited onto a Q235 steel substrate in various spraying ways. The WC-17Co splat deposited by HVOF showed a center hump and some molten areas, as well as some radial splashes presented at the edge of the splat. The WC-17Co splat deposited by WS presented a flattened morphology with no molten areas. However, the WC-17Co splat deposited by CS remained nearly spherical in shape and embedded into the substrate to a certain depth. All the WC-17Co coatings had the same phase compositions with that of feedstock. The microstructure of all the WC-17Co coatings was dense with no cracks or abscission phenomena between the coatings and substrate. Moreover, fine WC particles were formed in the coatings due to the fracture of coarse WC particles, and the content of fine WC particles in the cold-sprayed coating was significantly more than the other coatings. A stripe structure was formed by the slippage of fine WC particles with a plastic flow of Co binder in the warm-sprayed and cold-sprayed coatings. More fine WC particles, as well as the stripe structure, in the coatings were conducive to improve the microhardness and fracture toughness of the coating. The microhardness and fracture toughness of the cold-sprayed WC-17Co coating were the highest among the coatings. The main wear mechanism of all coatings was the groove and some peel-offs. The cold-sprayed WC-17Co coating with the lowest wear loss presented the highest wear resistance among the coatings. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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9 pages, 3392 KiB  
Article
Facile Preparation of YVO4: RE Films and the Investigation of Photoluminescence
by Taihui Chen, He Zhang, Zhihong Luo, Jun Liang and Xiaoli Wu
Coatings 2022, 12(4), 461; https://doi.org/10.3390/coatings12040461 - 29 Mar 2022
Cited by 2 | Viewed by 1578
Abstract
Facile preparation of YVO4 films was hydrothermally achieved within 1 h by using layered yttrium hydroxide (Y2(OH)5NO3·nH2O) films as the sacrificial precursor in the presence of excess NaVO3 at pH~8, without subsequent heat [...] Read more.
Facile preparation of YVO4 films was hydrothermally achieved within 1 h by using layered yttrium hydroxide (Y2(OH)5NO3·nH2O) films as the sacrificial precursor in the presence of excess NaVO3 at pH~8, without subsequent heat treatment. Detailed structures and optical properties of the products were obtained by using a combination of XRD, FT-IR, FE-SEM, HR-TEM, and PLE/PL techniques. The phase and morphological evolution from Y2(OH)5NO3·nH2O to YVO4 was unveiled by varying the reaction time. Photoluminescence spectra showed that the Eu3+ doped YVO4 films exhibited the characteristic emission of Eu3+, with the transition 5D07F2 (614 nm, red) being the dominant; while Dy3+ activator doped YVO4 films exhibited the characteristic emission of Dy3+, with the transition 4F9/26H13/2 (575 nm, green) being the most dominant. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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14 pages, 8335 KiB  
Article
Eroding the Surface of Rare Earth Microcrystals through Vanadate Ions for Considerable Improvement of Luminescence
by Jiao Qu, Juanjuan Liu and Qi Zhu
Coatings 2022, 12(2), 230; https://doi.org/10.3390/coatings12020230 - 10 Feb 2022
Viewed by 1111
Abstract
Developing an efficient approach to improve the luminescence of the phosphors without heating processing is a challenge, but attracts much attention. In the present paper, prismatic microcrystals of RE4O(OH)9NO3 (RE = Y, Eu) were synthesized by a hydrothermal [...] Read more.
Developing an efficient approach to improve the luminescence of the phosphors without heating processing is a challenge, but attracts much attention. In the present paper, prismatic microcrystals of RE4O(OH)9NO3 (RE = Y, Eu) were synthesized by a hydrothermal reaction at 180 °C for 24 h. The reaction with VO3 did not change the crystal structure of the microcrystals and VO3 substituting for NO3 anions did not take place. However, it contributed to the formation of amorphous particles containing VO3 on the surface of a prism, which is similar to the surface corrosion of a metal, called “surface eroding”. Therefore, surface modification was successfully achieved by eroding the surface of the microcrystals through the reaction with vanadate ions. As a result of VO3→Eu3+ energy transfer and the light-harvesting ability of VO3, the red emission intensity at 617 nm of the modified microcrystals greatly increased. Eroding the surface of rare earth microcrystals recommends a new paradigm for luminescence improvement of rare earth compounds. Full article
(This article belongs to the Special Issue Ceramic Films and Coatings: Properties and Applications)
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