Journal articles: 'Oxidation protection by thin ceramic coatings'

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Reis, Danieli A. P., Carlos de Moura Neto, Antônio Augusto Couto, Cosme Roberto Moreira Silva, Francisco Piorino Neto, and M. J. R. Barboza. "A Comparison between CoNiCrAlY Bond Coat and Zirconia Plasma Sprayed Coatings on Creep Tests." Materials Science Forum 591-593 (August 2008): 30–35. http://dx.doi.org/10.4028/www.scientific.net/msf.591-593.30.

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Thermomechanical and electrical properties of zirconia-based ceramics have led to a wide range of advanced and engineering ceramic applications like solid electrolyte in oxygen sensors, fuel cells and furnace elements and its low thermal conductivity has allowed its use for thermal barrier coatings for aerospace engine components. A comparison between CoNiCrAlY bond coat and zirconia plasma sprayed coatings on creep tests of the Ti-6Al-4V alloy was studied. The material used was commercial Ti-6Al-4V alloy. Yttria (8 wt.%) stabilized zirconia (YSZ) with a CoNiCrAlY bond coat was atmospherically plasma sprayed on Ti-6Al-4V substrates by Sulzer Metco Type 9 MB. Constant load creep tests were conducted on a standard creep machine in air on coated samples, at stress levels of 520 MPa at 500°C to evaluate the oxidation protection on creep of the Ti-6Al-4V alloy. Results indicate that the creep resistance of the ceramic coating was greater than metallic coating.

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Wierzbicka, Ewa, Borja Pillado, Marta Mohedano, Raul Arrabal, and Endzhe Matykina. "Calcium Doped Flash-PEO Coatings for Corrosion Protection of Mg Alloy." Metals 10, no. 7 (July 9, 2020): 916. http://dx.doi.org/10.3390/met10070916.

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This study demonstrates a significant improvement of the corrosion resistance of an AZ31B magnesium alloy achieved by the application of 1 μm-thin coatings generated by an environmentally friendly flash plasma electrolytic oxidation (FPEO) process in Ca-containing electrolytes. Two compounds with different solubility, calcium oxide (CaO) or calcium glycerophosphate (CaGlyP), were used as sources of Ca in the electrolyte. Very short durations (20–45 s) of the FPEO process were employed with the aim of limiting the energy consumption. The corrosion performance of the developed coatings was compared with that of a commercial conversion coating (CC) of similar thickness. The viability of the coatings in a full system protection approach, consisting of FPEO combined with an inhibitor-free epoxy primer, was verified in neutral salt spray and paint adhesion tests. The superior corrosion performance of the FPEO_CaGlyP coating, both as a stand-alone coating and as a full system, was attributed to the formation of a greater complexity of Ca2+ bonds with SiO2 and PO43− species within the MgO ceramic network during the in situ incorporation of Ca into the coating from a double chelated electrolyte and the resultant difficulties with the hydrolysis of such a network. The deterioration of the FPEO_CaGlyP coating during immersion was found over ten times slower compared with Ca-free flash-PEO coating.

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Parchovianský, Milan, Ivana Parchovianská, Peter Švančárek, Günter Motz, and Dušan Galusek. "PDC Glass/Ceramic Coatings Applied to Differently Pretreated AISI441 Stainless Steel Substrates." Materials 13, no. 3 (January 31, 2020): 629. http://dx.doi.org/10.3390/ma13030629.

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In this work, the influence of different cleaning procedures on adhesion of composite coatings containing passive ceramic and commercial glasses was investigated. Two compositions (C2c, D2-PP) of double-layer polymer-derived ceramic (PDC) coating systems, composed from bond coat and a top coat, were developed. In order to obtain adherent coatings, stainless steel substrates were cleaned by four different cleaning procedures. The coatings were then deposited onto the steel substrate via spray coating. Pretreatment by subsequent ultrasonic cleaning in acetone, ethanol and deionised water (procedure U) was found to be the most effective, and the resultant C2c and D2-PP coatings, pyrolysed at 850 °C, indicated strong adhesion without delamination or cracks, propagating at the interface steel/bond coat. In the substrate treated by sandblasting and chemical etching, small cracks in the bond coat were observed under the same pyrolysis conditions. After oxidation tests, all coatings, except for those subjected to the U-treated substrates, showed significant cracking in the bond coat. The D2-PP coatings were denser than C2c, indicating better protection of the substrate.

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Algahtani, Ali, Essam Mahmoud, Sohaib Khan, and Vineet Tirth. "Experimental Studies on Corrosion Behavior of Ceramic Surface Coating using Different Deposition Techniques on 6082-T6 Aluminum Alloy." Processes 6, no. 12 (November 26, 2018): 240. http://dx.doi.org/10.3390/pr6120240.

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Aluminum alloys cannot be used in aggressive corrosion environments application. In this paper, three different surface coating technologies were used to coat the 6082-T6 aluminum alloy to increase the corrosion resistance, namely Plasma Electrolytic Oxidation (PEO), Plasma Spray Ceramic (PSC) and Hard Anodizing (HA). The cross-sectional microstructure analysis revealed that HA coating was less uniform compared to other coatings. PEO coating was well adhered to the substrate despite the thinnest layer among all three coatings, while the PSC coating has an additional loose layer between the coat and the substrate. X-ray diffraction (XRD) analysis revealed crystalline alumina phases in PEO and PSC coatings while no phase was detected in HA other than an aluminum element. A series of electrochemistry experiments were used to evaluate the corrosion performances of these three types of coatings. Generally, all three-coated aluminum showed better corrosion performances. PEO coating has no charge transfer under all Inductive Coupled Plasma (ICP) tests, while small amounts of Al3+ were released for both HA and PSC coatings at 80 °C. The PEO coating showed the lowest corrosion current density followed by HA and then PSC coatings. The impedance resistance decreased as the immersion time increased, which indicated that this is due to the degradation and deterioration of the protective coatings. The results indicate that the PEO coating can offer the most effective protection to the aluminum substrate as it has the highest enhancement factor under electrochemistry tests compared to the other two coatings.

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CHEN, CHUANZHONG, QING DONG, and DIANGANG WANG. "MICROSTRUCTURE AND ELEMENT DISTRIBUTIONS OF CERAMIC-LIKE COATINGS ON THE AZ91 ALLOY BY MICRO-ARC OXIDATION." Surface Review and Letters 13, no. 01 (February 2006): 63–68. http://dx.doi.org/10.1142/s0218625x06007846.

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Ceramic-like coatings were deposited on the substrate of the AZ91 alloy by micro-arc oxidation (MAO). Many methods like X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron diffraction spectroscopy (EDS) were used to analyze the structure and composition of the coating. XRD showed that the MAO coating was mainly composed of MgO . The results of SEM showed that the coating surface possessed a porous microstructure and the pore size was in the range of 1–3 μm. EDS indicated that the coating matrix was relatively dense and had a homogeneous thickness. The element silicon from the applied electrolyte could be absorbed into the coating in the MAO process. The hardness of the MgO coatings could reach 513 HV0.025 that was about four times higher than that of the substrate. It is expected that the coatings have a great potential in the surface protection of magnesium alloys.

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Agüero, Alina, Marcos Gutiérrez, and Raúl Muelas. "Steam Oxidation Testing of Coatings for Next Generation Steam Power Plant Components." Materials Science Forum 522-523 (August 2006): 205–12. http://dx.doi.org/10.4028/www.scientific.net/msf.522-523.205.

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To achieve higher power generation efficiency in steam turbines, operating temperatures are expected to rise from 550°C to 650°C. The use of oxidation resistant coatings on currently available materials, with high creep strength but inferior steam oxidation resistance, is being explored in order to accomplish this goal in the context of the European project “Coatings for Supercritical Steam Cycles” (SUPERCOAT). Coating techniques have been chosen on the basis of being potentially appropriate for coating steam turbine components: the application of metallic and ceramic slurries, pack cementation and the deposition of alloyed and cermet materials by thermal spray. The coatings were characterised by metallography, SEM-EDS and XRD and steam oxidation and thermal cycling laboratory testing was carried out at 650º C. In this presentation, the testing results of selected coatings will be shown including those which exhibit the most promising behaviour. For instance, slurry aluminides have been exposed to steam at 650°C for more than 38,000 h (test ongoing) without evidence of substrate attack. Some HVOF coatings such as FeAl, NiCr and FeCr also have shown excellent behaviour. The results have provided information regarding the mechanism of protection and degradation of these coatings as well as insight into new coating development.

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Sebastian, Jobin, Abyson Scaria, and Don George Kurian. "Development & Characterization of Alumina Coating by Atmospheric Plasma Spraying." Applied Mechanics and Materials 877 (February 2018): 104–9. http://dx.doi.org/10.4028/www.scientific.net/amm.877.104.

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Ceramic coatings are applied on metals to prevent them from oxidation and corrosion at room as well as elevated temperatures. The service environment, mechanisms of protection, chemical and mechanical compatibility, application method, control of coating quality and ability of the coating to be repaired are the factors that need to be considered while selecting the required coating. The coatings based on oxide materials provides high degree of thermal insulation and protection against oxidation at high temperatures for the underlying substrate materials. These coatings are usually applied by the flame or plasma spraying methods. The surface cleanliness needs to be ensured before spraying. Abrasive blasting can be used to provide the required surface roughness for good adhesion between the substrate and the coating. A pre bond coat like Nickel Chromium can be applied on to the substrate material before spraying the oxide coating to avoid chances of poor adhesion between the oxide coating and the metallic substrate. Plasma spraying produces oxide coatings of greater density, higher hardness, and smooth surface finish than that of the flame spraying process Inert gas is often used for generation of plasma gas so as to avoid the oxidation of the substrate material. The work focuses to develop, characterize and optimize the parameters used in Al2O3 coating on transition stainless steel substrate material for minimizing the wear rate and maximizing the leak tightness using plasma spray process. The experiment is designed using Taguchi’s L9 orthogonal array. The parameters that are to be optimized are plasma voltage, spraying distance and the cooling jet pressure. The characterization techniques includes micro-hardness and porosity tests followed by Grey relational analysis of the results

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Froitzheim, J., and J. E. Svensson. "Nanocoatings for SOFC Interconnects - Mitigating Chromium Volatilization and Improving Corrosion Properties." Materials Science Forum 696 (September 2011): 412–16. http://dx.doi.org/10.4028/www.scientific.net/msf.696.412.

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Two important degradation mechanisms in Solid Oxide Fuel Cells (SOFC) are directly related to the metallic interconnects. The formation of volatile chromium oxides from metallic interconnects commonly causes fast degradation in cell performance due to poisoning the cathode. Secondly is the ability of the metallic interconnect to form a thin protective oxide one of the most important lifetime limiting factors for SOFC. Chromium volatilization of various uncoated steels is studied as a function of temperature by a recently developed denuder technique which allows time resolved quantification of volatile chromium species. The inhibition of Cr evaporation by Co thin film coatings (800nm) is investigated; it will be shown that these coatings are more effective than much thicker ceramic coatings that are commonly used for this purpose. In order to increase the lifetime of the metallic components in SOFC nano-coatings of reactive elements (RE) have been investigated as well. The application of such coatings can reduce the corrosion rates substantially and thus increase the lifetime of the fuel cell stack. It will be shown that it is possible to combine the positive effects of RE with the beneficial effects of a Co coating and thus to obtain an interconnect material with low Cr evaporation and increased oxidation resistance.

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Liu, Peng, Lian Qi Wei, Shu Feng Ye, Xun Zhou, Yu Sheng Xie, and Yun Fa Chen. "Preparation and Property of Ceramic Matrix Coating of Anti-Oxidation for Stainless Steel at High Temperature by Slurry Method." Advanced Materials Research 105-106 (April 2010): 448–50. http://dx.doi.org/10.4028/www.scientific.net/amr.105-106.448.

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In this paper, the new high temperature ceramic matrix coating of anti-oxidation for stainless steel was prepared by slurry method. With the research about oxidation resistance of ceramic matrix coating formed on stainless steel, the effect of initial melting temperature, melting temperature range and thermal expansion coefficients of ceramic sintering change on protective properties of high temperature coating prepared at 1250°C is investigated, and then high temperature sintering ceramic with high-performance is gained through optimization. Through the test of TG-DTA and XRD to the coating, study on high temperature oxidation resistance of ceramic coating and the structure changing of the scale with coating from SEM images and photos, it is shown that the ceramic coating has excellent oxidation resistant properties, the weight loss with coating decrease more than 85%.

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Kyzioł, Lesław, and Aleksandr Komarov. "Influence of Micro-Arc Oxidation Coatings on Stress Corrosion of AlMg6 Alloy." Materials 13, no. 2 (January 12, 2020): 356. http://dx.doi.org/10.3390/ma13020356.

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This paper shows results of a study on the corrosion behavior of micro-arc oxidation (MAO) coatings sampled from the AlMg6 alloy. The alloy was simultaneously subjected to a corrosive environment and static tensile stress. For comparative purposes, the tests were run for both coated samples and samples without coatings. The research was conducted at a properly prepared stand; the samples were placed in a glass container filled with 3.5% NaCl aqueous solution and stretched. Two levels of tensile stress were accepted for the samples: σ1 = 0.8R0.2 σ2 = R0.2, and the tests were run for two time intervals: t1 = 480 h and t2 = 1000 h. Prolonged stress corrosion tests (lasting up to 1000 h) showed that the samples covered with ceramic coatings demonstrated significantly higher corrosion resistance than the samples without the coatings. Protective properties of the coating could be explained by its structure. Surface pores were insignificant, and their depth was very limited. The porosity level of the main coating layer was 1%. Such a structure of coating and its phase composition provided high protective properties.

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Sobolev, Alexander, Israel Wolicki, Alexey Kossenko, Michael Zinigrad, and Konstantin Borodianskiy. "Coating Formation on Ti-6Al-4V Alloy by Micro Arc Oxidation in Molten Salt." Materials 11, no. 9 (September 4, 2018): 1611. http://dx.doi.org/10.3390/ma11091611.

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Micro Arc Oxidation (MAO) is an electrochemical surface treatment process to produce oxide protective coatings on some metals. MAO is usually conducted in an aqueous electrolyte, which requires an intensive bath cooling and leads to the formation of a coating containing impurities that originate in the electrolyte. In the current work, we applied an alternative ceramic coating to the Ti-6Al-4V alloy using the MAO process in molten nitrate salt at a temperature of 280 °C. The obtained coating morphology, chemical and phase composition, and corrosion resistance were investigated and described. The obtained results showed that a coating of 2.5 µm was formed after 10 min of treatment, containing titanium oxide and titanium‒aluminum intermetallic phases. Morphological examination indicated that the coating is free of cracks and contains round, homogeneously distributed pores. Corrosion resistance testing indicated that the protective oxide coating on Ti alloy is 20 times more resistive than the untreated alloy.

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Yang, Wonchul, Choong-Heui Chung, Sangyeob Lee, Jong Won Lee, and Joon Sik Park. "Microstructures and Oxidation Behavior According to Nb:Mo Ratio in a Nb–Mo–Si System with Si Pack Cementation Coatings." Coatings 9, no. 12 (November 20, 2019): 772. http://dx.doi.org/10.3390/coatings9120772.

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Research is being conducted on Mo- and Nb-based alloys that are used in the aerospace sector, including those used for advanced gas turbines and aircraft engines. There is a limit to using Mo, which has a high density among refractory metals, and a few studies exist describing the addition of Nb to Mo–silicide alloys. There is a lack of guidance research on the basic Nb:Mo ratio of alloys, and it is necessary to study how to improve oxidation resistance. Therefore, this study aims to improve oxidation resistance by controlling the ratio of Nb and Mo in (Nbx, Moy)Si2 coating layers with Si pack cementation coatings on Nb–Mo alloys. Static oxidation tests were carried out at 1200 °C for 6 h to confirm the oxidation characteristics. As a result, a SiO2 or SiO2 + Nb2O5 ceramic protective layer was formed on the surface. After the oxidation tests, alloys with a Nb content of less than 35 at.% were found to protect the surface. The ratios of Nb and Mo in the Nb–Mo alloy and silicide coating layer were compared, and the improvement of oxidation resistance is discussed in terms of microstructural evolution.

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Lee, Kang N., Nathan S. Jacobson, and Robert A. Miller. "Refractory Oxide Coatings on SiC Ceramics." MRS Bulletin 19, no. 10 (October 1994): 35–38. http://dx.doi.org/10.1557/s088376940004820x.

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Silicon-based ceramics are leading candidate materials for high-temperature structural applications such as heat exchangers, advanced gas turbine engines, and advanced internal combustion engines. They have excellent oxidation resistance in clean oxidizing environments due to the formation of a slow-growing silica scale (SiO2). However, durability in high-temperature environments containing molten salts, water vapor, or a reducing atmosphere can limit their applications. Molten salts react with silica scale to form liquid silicates. Oxygen readily diffuses through liquid silicates and rapidly oxidizes the substrate. High water vapor levels lead to hydrated silica species, such as Si(OH)4(g) and subsequent evaporation of protective scale. Complex combustion atmospheres containing oxidizing (CO2, H2O) and reducing (CO, H2) gases form SiO2 and then reduce it to SiO(g). In situations with extremely low partial pressures of oxidant, direct formation of SiO(g) occurs. All these reactions can potentially limit the formation of a protective silica scale and thus lead to an accelerated or a catastrophic degradation.One approach overcoming these potential environmental limitations is to apply a barrier coating which is environmentally stable in molten salts, water vapor, and/or reducing atmospheres. Refractory oxides such as mullite (3Al2O3 · 2SiO2), yttria-stabilized zirconia (ZrO2-Y2O3), or alumina (Al2O3) are promising candidate coating materials because of their excellent environmental stability in these severe conditions. Refractory oxide coatings can also serve as thermal barrier coatings because of their low thermal conductivity. Key requirements for an adherent and durable barrier coating include coefficient of thermal expansion (CTE) match and chemical compatibility with the substrate. Mullite in general meets all the requirements and thus appears most promising.

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Wu, Chao, Xiaochuan Pan, Fan Lin, Guochun Chen, Lida Xu, Yingjun Zeng, Yingping He, Daoheng Sun, and Zhenyin Hai. "Al2O3-Modified Polymer-Derived Ceramic SiCN High-Temperature Anti-Oxidative Composite Coating Fabricated by Direct Writing." Polymers 14, no. 16 (August 12, 2022): 3281. http://dx.doi.org/10.3390/polym14163281.

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A reliable protective layer is one of the main challenges in preventing oxidation of thin film sensors to achieve accurate, effective, and stable readings at high temperatures. In this work, an Al2O3-modified polymer-derived ceramic SiCN composite coating fabricated by a direct-writing technique is utilized as a protective layer for thin film sensors. The microstructure evolution of the Al2O3/SiCN films is examined herein. The protective layer exhibits excellent oxidation resistance and thermal stability at high temperatures up to 1000 °C, which contributes to improving the stability and lifetime of thin film sensors in extreme environments. The TiB2/SiCN thin film resistive grid with the Al2O3/SiCN composite film as a protective layer is fabricated and tested. The results indicate that the coating can protect the TiB2/SiCN thin film resistive grid at high temperatures up to 1000 °C, which is about 200 °C higher than that of the TiB2/SiCN thin film resistive grid without a protective layer. The resistance change rates of the TiB2/SiCN thin film resistive grid with a protective layer are 0.5%/h at 900 °C and 10.7%/h at 1000 °C.

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Siripongsakul, Thamrongsin, Thublaor Tummaporn, Vatit Prajakesakul, Sorana Kachaban, and Somrerk Chandra-ambhorn. "Chromia Evaporation of Ferritic Stainless Steel AISI430 Coated by (La,Sr)CrO₃ Perovskite and Mn-Co Oxide Spinel." Key Engineering Materials 728 (January 2017): 166–71. http://dx.doi.org/10.4028/www.scientific.net/kem.728.166.

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A ferritic stainless steel has been intensively studied for its potential in application as an interconnect for a solid oxide fuel cell (SOFC). However, at such a high operating temperature chromia in the gaseous phase can contaminate the cathode of the SOFC, and consequently the performance of the device degrades rapidly. To overcome this problem, two kind of ceramics, (La,Sr)CrO3 perovskite and Mn-Co oxide spinel were prepared as coatings on the stainless steel AISI 430 to investigate on chromia evaporation at 800°C. In this present work, the (La,Sr)CrO3 and Co-Mn layers were formed by a sol-gel dip coating and an electrodeposition technique, respectively. The coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), rates of oxidation and rates of chromia evaporation. The coated specimens exhibited the protective behavior with a lower rate of oxidation, as well as a lower rate of chromium evaporation than the uncoated specimen both in the atmosphere of dry and humidified oxygen. But the reduction of the chromia evaporation rates of (La,Sr)CrO3 coatings was insignificant due to the presence of Cr2O3 phase in the coatings.

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Sienkiewicz, Judyta, Seiji Kuroda, Hideyuki Murakami, Hiroshi Araki, Maciej Giżyński, and Krzysztof J. Kurzydłowski. "Fabrication and Oxidation Resistance of TiAl Matrix Coatings Reinforced with Silicide Precipitates Produced by Heat Treatment of Warm Sprayed Coatings." Journal of Thermal Spray Technology 27, no. 7 (September 5, 2018): 1165–76. http://dx.doi.org/10.1007/s11666-018-0751-x.

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Abstract Ti-Al-based intermetallics are promising candidates as coating materials for thermal protection systems in aerospace vehicles; they can operate just below the temperatures where ceramics are commonly used, and their main advantage is the fact that they are lighter than most other alloys, such as MCrAlY. Therefore, Ti-Al-Si alloy coatings with five compositions were manufactured by spraying pure Ti and Al-12 wt.% Si powders using warm spray process. Two-stage hot pressing at 600 and 1000 °C was applied to the deposits in order to obtain titanium aluminide intermetallic phases. The microstructure, chemical composition, and phase composition of the as-deposited and hot-pressed coatings were investigated using SEM, EDS, and XRD. Applying of hot pressing enabled the formation of dense coatings with porosity around 0.5% and hard Ti5(Si,Al)3 silicide precipitates. It was found that the Ti5(Si,Al)3 silicides existed in two types of morphologies, i.e., as large particles connected together and as small isolated particles dispersed in the matrix. Furthermore, the produced coatings exhibited good isothermal and cyclic oxidation resistance at a temperature of 750 °C for 100 h.

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Sarkar, S., S. Datta, S. Das, and D. Basu. "Oxidation protection of gamma-titanium aluminide using glass–ceramic coatings." Surface and Coatings Technology 203, no. 13 (March 2009): 1797–805. http://dx.doi.org/10.1016/j.surfcoat.2008.12.029.

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Burkov, Alexander, and Valeria Krutikova. "Deposition of titanium silicide on stainless steel AISI 304 surface." Metal Working and Material Science 24, no. 4 (December 15, 2022): 127–37. http://dx.doi.org/10.17212/1994-6309-2022-24.4-127-137.

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Introduction. Metal-ceramic coatings based on titanium silicide are promising for protecting stainless steel AISI 304 from wear, corrosion and high-temperature oxidation. Purpose of the work: to investigate the stainless steel AISI 304 surface layer structure after electrospark deposition in a mixture of titanium granules with silicon powder, and to study oxidation resistance, corrosion resistance and tribotechnical properties of the obtained coatings. Research methodology. Fe-Ti-Si coatings on the stainless steel AISI 304 samples were obtained by electrospark machining with a non-localized electrode consisting of titanium granules and 2.6-6 vol.% mixture of titanium and crystalline silicon powders. Results and discussion: it is shown that a stable positive gain of the cathode is observed when the proportion of silicon in the powder mixture does not exceed 32 vol.%. The phase composition of the coatings includes: a solid solution of chromium in iron, titanium silicide Ti5Si3, titanium and silicon, which is confirmed by the energy dispersion analysis data. The microhardness of Fe-Ti-Si coatings ranges from 10.05 to 12.86 GPa, which is 5-6 times higher than that of uncoated steel AISI 304. The coefficient of friction of the coatings is about 20% lower compared to steel AISI 304 and hovers around 0.71-0.73. Wear tests in dry sliding mode show that Fe-Ti-Si coatings can increase the wear resistance of steel AISI 304 up to 6 times. The oxidation resistance of the coatings at a temperature of 900 ̊С is 7-12 times higher as compared to steel AISI 304. The conducted studies have shown that new electrospark Fe-Ti-Si coatings can increase corrosion resistance, oxidation resistance, microhardness, as well as reduce the coefficient of friction and wear rate of the stainless steel AISI 304 surface.

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Corral, Erica L., and Ronald E. Loehman. "Ultra-High-Temperature Ceramic Coatings for Oxidation Protection of Carbon–Carbon Composites." Journal of the American Ceramic Society 91, no. 5 (May 2008): 1495–502. http://dx.doi.org/10.1111/j.1551-2916.2008.02331.x.

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Chen, Minghui, Wenbo Li, Mingli Shen, Shenglong Zhu, and Fuhui Wang. "Glass–ceramic coatings on titanium alloys for high temperature oxidation protection: Oxidation kinetics and microstructure." Corrosion Science 74 (September 2013): 178–86. http://dx.doi.org/10.1016/j.corsci.2013.04.041.

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van Roode, M., J. R. Price, and C. Stala. "Ceramic Oxide Coatings for the Corrosion Protection of Silicon Carbide." Journal of Engineering for Gas Turbines and Power 115, no. 1 (January 1, 1993): 139–47. http://dx.doi.org/10.1115/1.2906668.

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Silicon carbide is currently used as a structural material for heat exchanger tubes and related applications because of its excellent thermal properties and oxidation resistance. Silicon carbide suffers corrosion degradation, however, in the aggressive furnace environments of industrial processes for aluminum remelting, advanced glass melting, and waste incineration. Adherent ceramic oxide coatings developed at Solar Turbines Incorporated, with the support of the Gas Research Institute, have been shown to afford corrosion protection to silicon carbide in a simulated aluminum remelt furnace environment as well as in laboratory-type corrosion testing. The coatings are also protective to silicon carbide-based ceramic matrix composites.

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Chen, Kuiying, Dongyi Seo, and Pervez Canteenwalla. "The Effect of High-Temperature Water Vapour on Degradation and Failure of Hot Section Components of Gas Turbine Engines." Coatings 11, no. 9 (September 2, 2021): 1061. http://dx.doi.org/10.3390/coatings11091061.

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For the past decade, the aviation industry has been adopting sustainable aviation fuels (SAF) for use in aircraft to reduce the impact of aviation on climate change. Also, some nations look to SAF as an option for energy security for their military fleets. Understanding the critical impact of alternative fuel sources on hardware will provide the gas turbine industry with strategic options in sustainability and maintainability of the existing and new fleets. The alternative fuels with high hydrogen/carbon ratio (H/C) (such as synthetic paraffinic kerosenes (SPK)) could produce more water vapour content than the conventional jet fuels upon combustion, and this increased water vapour level could exert a significant impact over the long-term durability on hot section components such as the substrate blades, oxidation resistant coatings, thermal barrier coatings (TBCs), environmental barrier coatings (EBCs), resulting in an accelerated degradation of the turbine components. The possible detrimental effect of high-temperature water vapour on degradation and lifespan of hot section components was examined. Examples were specifically given on degradation and spallation of thermally grown oxides (TGO), formation of non-protective oxides and ceramics topcoats in TBCs. Results show that water vapour can lead to volatilization of TGO (Al2O3), and is responsible for the formation of non-protective oxides in both Pt-modified β-NiAl and MCrAlY coatings, leading to their early spallation. However, water vapour does not appear to directly affect the ceramic topcoat of the TBC. For EBCs coated on SiC-based substrates, the substrate recession via silica (TGO) volatilization was reviewed. These EBCs were observed undergoing degradation in highly hostile environments, e.g., constantly operating under high temperatures, pressures, and velocities condition in the presence of water vapour steam. The review intends to provide a perspective of high-temperature water vapour effect on the EBCs’ topcoat properties such as durability, degradation, crack nucleation and crack growth, and possible guidance for mitigating these degradation effects.

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Merisalu, Maido, Lauri Aarik, Jekaterina Kozlova, Hugo Mändar, Aivar Tarre, Helle-Mai Piirsoo, and Väino Sammelselg. "Al alloy protection via ultra-thin ceramic coatings and different surface pretreatments." Surface and Coatings Technology 435 (April 2022): 128240. http://dx.doi.org/10.1016/j.surfcoat.2022.128240.

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Boissonnet, Germain, Ewa Rzad, Romain Troncy, Tomasz Dudziak, and Fernando Pedraza. "High Temperature Oxidation of Enamel Coated Low-Alloyed Steel 16Mo3 in Water Vapor." Coatings 13, no. 2 (February 2, 2023): 342. http://dx.doi.org/10.3390/coatings13020342.

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New types of ceramic coatings based on SiO2-Na2O-B2O3-TiO2 oxide phases were investigated as protection for boiler steel in power generation systems. Low-alloyed Cr-Mo 16Mo3 steel was coated with different compositions of enamel coatings to assess the protective potential of these coatings under water vapor at high temperatures. Oxidation at 650 °C for 50 h in Ar + water vapor was performed in a TGA apparatus to investigate the oxidation kinetics. The results indicate that the ceramic coatings provided a high degree of protection for the steel exposed to such conditions compared to the uncoated 16Mo3 steel. Furthermore, despite the formation of cracks in the coatings, no spallation from the steel surface was observed. Interconnected porosity in the coatings is suspected to provoke interfacial degradation.

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Cui, Shi Hai, Hong Tao Tang, Jian Yu Li, and Jian Min Han. "Corrosion Protection of a SiCp/ZL101 Composites by Using Plasma Electrolytic Oxidation Method." Advanced Materials Research 79-82 (August 2009): 1071–74. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.1071.

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A dense ceramic coatings with a thickness of 95μm was fabricated on a SiCp/ZL101 aluminum composites by using a plasma electrolytic oxidation(PEO) method. The XRD analysis showed that the PEO coating was mainly composed of α-Al2O3 γ-Al2O3 and mullite.The corrosion resistance of the PEO coatings and SiCp/ZL101 aluminum composites was estimated by the immersion test, salt spray test and electrochemical test. All the test results showed that the corrosion resistance of the composite was improved by the existence of the ceramic coating.

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Hu, Han Jun, Hui Zhou, Yu Gang Zheng, Kai Feng Zhang, and Zhi Hua Wan. "The Improved Friction Properties of Bonded MoS2 Films by MAO Treating of Al Substrate." Applied Mechanics and Materials 275-277 (January 2013): 1911–14. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.1911.

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The bonded MoS2 films are widely used as solid lubricants in aerospace mechanisms due to their excellent tribological properties. Traditionally, the MoS2 was directly bonded on the Al substrate that was only treated by the technique named of sandblast. For improving the tribological properties of MoS2 films, micro arc oxidation (MAO) instead of sandblast was introduced as a new technique for treating of Al substrate. In this article, the tribological properties of MoS2 films which were bonded on different surface of Al substrate as mentioned above were discussed, respectively. It was concluded from the test results that the MoS2 films bonded on substrate treated by MAO have better tribological properties than those samples treated by sandblast. The endurance life against abrasion of the former is as high as twenty times of the latter by the stand test method of ball on disk using the UMT Multi-Specimen Test System. This test results could be illustrated by the following reasons. The first is the porous microstructures of MAO ceramic coatings on the Al substrate. The coatings have numerous pits to be good at increasing the binding force with the MoS2 films, and the pits can also provide a MoS2 lubricants reservoir during processes of friction. Both of them improved the MoS2 film’s ability of wear-protective. The second is that hardness of the coating is higher than the Al, and this ensures well wearing resistance, especially in practical application to big load-supporting moving parts, such as bearing, gear, etc…

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Wu, Pei Nian, J. J. Xi, Jun Zhao, and T. J. Wang. "Preparation of Compact Micro-Arc Oxidation Coatings on Aluminum Alloys." Applied Mechanics and Materials 33 (October 2010): 492–95. http://dx.doi.org/10.4028/www.scientific.net/amm.33.492.

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In this paper, a hard and thin coating with no loose layer was formed on the surface of the aluminum LC4 by bipolar micro-arc oxidation power, and the influence of ratio J of the negative current density to the positive current density on the thickness h and the hardness H of micro-arc oxidation coatings was studied. By SEM and other modern materials testing and analyzing techniques, the microstructures of the micro-arc oxidation ceramic coatings were tested and analyzed. It was showed that the micro-structure is compact, and the ceramic coating almost has non-porous layer.

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Zhitomirsky, I., and A. Petric. "Cathodic Electrodeposition of Ceramic Coatings for Oxidation Protection of Materials at Elevated Temperatures." Canadian Metallurgical Quarterly 41, no. 4 (December 2002): 497–505. http://dx.doi.org/10.1179/cmq.2002.41.4.497.

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Li, Zhijun, Yi Yuan, Pengpeng Sun, and Xiaoyan Jing. "Ceramic Coatings of LA141 Alloy Formed by Plasma Electrolytic Oxidation for Corrosion Protection." ACS Applied Materials & Interfaces 3, no. 9 (August 24, 2011): 3682–90. http://dx.doi.org/10.1021/am200863s.

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Manocha, L. M., and Satish M. Manocha. "Studies on solution-derived ceramic coatings for oxidation protection of carbon-carbon composites." Carbon 33, no. 4 (1995): 435–40. http://dx.doi.org/10.1016/0008-6223(94)00168-y.

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Michalak, Michał, Remigiusz Michalczewski, Edyta Osuch-Słomka, Demófilo Maldonado-Cortés, and Marian Szczerek. "The Effect of Temperature on Wear Mechanism of the AlCrN Coated Components." Key Engineering Materials 674 (January 2016): 233–38. http://dx.doi.org/10.4028/www.scientific.net/kem.674.233.

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The aim of the paper was to investigate the temperature effect on the wear mechanism of AlCrN coated components. The coating was deposited by Physical Vapour Deposition process (PVD) on WC/Co substrate. Tribological tests were performed in sliding conditions using high temperature T‑21 tribotester, produced by ITeE-PIB Radom. The tests were performed in a ball-on-disc configuration (Si3N4 ceramic ball), under dry friction conditions at room temperature, 600°C and 750°C. An optical microscope, interferometer, and scanning electron microscope were used to analyse the worn surfaces. Following this study, it was found that wear resistance of the coating AlCrN tribosystem depended on the temperature. The biggest wear was reported at room temperature. At 600°C the intensity of wear of the coating was 4-fold lower, and at 750°C wear was 6-fold lower that at room temperature. High temperature wear resistance of AlCrN coating involves creating protective oxide layer. Performed analysis of structure the surface layer, showed a much higher content of oxygen in wear scar than outside. At high temperatures, friction additional intensified oxidation process thus the amount of oxygen in surface layer increased with temperature. Oxide layer, Al2O3 and Cr2O3 probably, created at high temperature was a barrier to further oxidation of the coating and had very high wear resistance at high temperature.

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Choules, B. D., and K. Kokini. "Architecture of Functionally Graded Ceramic Coatings Against Surface Thermal Fracture." Journal of Engineering Materials and Technology 118, no. 4 (October 1, 1996): 522–28. http://dx.doi.org/10.1115/1.2805951.

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An analytical study was performed to study the effect of architecture on the initiation of surface cracking in multilayer ceramic coatings. Two modes of crack initiation were considered: 1) tension resulting from stress relaxation, and 2) cyclic thermal fatigue. Transient temperature distributions were determined using a finite difference technique, and stress distributions were calculated using a multilayer beam theory. The results showed that as more layers were added and as the ceramic coating became thinner, lower maximum surface stresses resulted during cooling after stress relaxation. Also, a thick eight layer coating had similar thermal fatigue behavior to a thin single layer coating. It was determined that a thick multilayer coating adds a significant amount of thermal protection when compared to a thin single layered coating.

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Szczucka-Lasota, Bożena, and Wojciech Majewski. "Oxidation Resistance of Coating Obtained by Innovative Methods for Energy Boilers." Advanced Materials Research 1036 (October 2014): 152–57. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.152.

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The material conception of manufacture nanocomposite coatings with high dispersion phases are presented. The structure surface was obtained by modified technology HVOF aand PMR with micro-jet cooling. The macro and microstructure of composition coatings after the high temperature corrosion test are presented. The oxidation resistance of coatings contain multilayer structure with high dispersion ceramic particles are obtained. The presented coatings use to basic protection to wear and corrosion condition or modified surface of multilayer coatings in the energy boiler.

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Góral, Marek, Tadeusz Kubaszek, Barbara Kościelniak, Marcin Drajewicz, and Mateusz Gajewski. "Microstructure and Oxidation Resistance of Thermal Barrier Coatings with Different Ceramic Layer." Solid State Phenomena 320 (June 30, 2021): 31–36. http://dx.doi.org/10.4028/www.scientific.net/ssp.320.31.

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Thermal barrier coatings are widely used for protection of gas turbine parts against high temperature oxidation and hot corrosion. In present work the microstructural assessment of TBCs produced by atmospheric plasma spray (APS) method was conducted. Three types of ceramic powders were used: magnesia- stabilized zirconia oxide (Metco 210), yttria stabilized zirconia oxide (YSZ -Metco 204) and fine-grained YSZ – Metco 6700. As a base material the Inconel 713 was used as well and CoNiCrAlY was plasma sprayed (APS) as a bond coat. The thickness of all ceramic layers was in range 80 – 110 μm. The elemental mapping of cross-section of magnesia-stabilized zirconia showed the presence of Mg, Zr and O in outer layer. In the YSZ ceramic layer the Y, Zr and O were observed during elemental mapping. The isothermal oxidation test was conducted at 1100 °C for 500 h in static laboratory air. On all samples the delamination and spallation of ceramic layers was observed. Chemical composition analysis of coatings showed the presence of two areas: the first one contained elements from bond coats: Ni, Cr, Al, Co and second area contained O, Cr Co and O that suggest the scale formation. The obtained results showed the total degradation of all ceramic layers as a result of internal stresses in bond-coat. Microscopic analysis showed the areas with complete degradation of bond coats and formation of thick oxides layer.

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Zhang, Min Wei, Cao Gao, Yue Xia Ding, Jie Tao, and Tao Wang. "Lead-Free Oxidation- Resistant Glass-Ceramic Coating for Heat Processing of Ti-6Al-4V Alloy." Key Engineering Materials 373-374 (March 2008): 601–4. http://dx.doi.org/10.4028/www.scientific.net/kem.373-374.601.

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Now the oxidation-resistant glass-ceramic coatings have been widely used in reducing surface oxidation of Ti alloys during heat process. In present investigation, a lead-free glass-ceramic coating with wider protection temperature range was developed to protect Ti-6Al-4V alloy from oxidation. The phase compositions of the present coating and the oxygen distributions in the surface layers of Ti-6Al-4V specimens were investigated by means of XRD, as well as the metallographs of cross-section were observed and the depths of oxidized layers were determined by microhardness analysis. The results show that the present glass-ceramic coating can provide the oxidation-resistant effect over the temperature range of 500-1000oC in ambient air, with an environmentally friendly lead-free coating composition.

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Góral, Marek, Maciej Pytel, Pawel Sosnowy, Slawomir Kotowski, and Marcin Drajewicz. "Microstructural Characterization of Thermal Barrier Coatings Deposited by APS and LPPS Thin Film Methods." Solid State Phenomena 197 (February 2013): 1–5. http://dx.doi.org/10.4028/www.scientific.net/ssp.197.1.

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In the paper first results of TBCs deposition by LPPS-Thin Film method were presented. The LPPS-Thin Film is a new type of processes for deposition of thermal barrier coatings. In this method deposition of thin ceramic layer in very low pressure is possible as well as coatings with columnar structure (in plasma spraying-physical vapour deposition process). The MeCrAlY bond coats were deposited by APS method. The overaluminising by CVD method of conventional MeCrAlY was also conducted. The analysis of microstructure of both type bond coats as well as outer ceramic layer were presented using light and scanning electron microscopy methods. Results of EDS microanalysis showed the increasing of aluminum content in outer zone of overaluminized MeCrAlY coating. In ceramic layer the columnar structure were observed which was connected with powder evaporation during plasma spraying. The new type of MeCrAlY-NiAl bondcoat could increase the oxidation of TBCs deposited by LPPS Thin Film method.

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Baufeld, Bernd, and Omer Van der Biest. "Development of Thin Ceramic Coatings for the Protection against Temperature and Stress Induced Rumpling of the Metal Surface of Turbine Blades." Key Engineering Materials 333 (March 2007): 273–76. http://dx.doi.org/10.4028/www.scientific.net/kem.333.273.

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In order to obtain a protection against temperature and stress induced detrimental rumpling of the metal surface of turbine blades, thin ceramic coatings are suggested. As a cheap and fast method for the fabrication of a ceramic zirconia coating, electrophoretic deposition on a Ni based superalloy is described. Crack free, 0.15 mm thick coatings with homogenous morphology were obtained. The Young’s modulus and the damping property of the ceramic coating, derived from the impulse excitation technique, are investigated as a function of the temperature up to 1000°C.

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Patscheider, Jörg. "Nanocomposite Hard Coatings for Wear Protection." MRS Bulletin 28, no. 3 (March 2003): 180–83. http://dx.doi.org/10.1557/mrs2003.59.

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AbstractNanocomposite thin films successfully promote hardness, oxidation resistance, improved wear behavior, and other properties relevant for wear-reducing coatings. Such coatings are composed of nanocrystalline grains of transition-metal nitrides or carbides surrounded by an amorphous hard matrix. The properties of nanocomposite coatings, especially hardness, are directly linked to nanostructure. The codeposition of the amorphous and nanocrystalline phases of different compositions results in different morphologies, which in turn affect the coating's properties. A maximum hardness ranging from 30 GPa to reported values above 60 GPa has been observed for most nanocomposite coatings. To obtain enhanced hardness, the domain size of the nanocrystalline phase must be below 10 nm, while the thickness of the amorphous layer separating the nanocrystals must be maintained at only a few atomic bond lengths. The prime reason for the hardness enhancement is the absence of dislocation activity.

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Motz, Günter, T. Kabelitz, and Günter Ziegler. "Polymeric and Ceramic-Like SiCN Coatings for Protection of (Light) Metals against Oxidation and Corrosion." Key Engineering Materials 264-268 (May 2004): 481–84. http://dx.doi.org/10.4028/www.scientific.net/kem.264-268.481.

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40

Abdul-Aziz, Ali, Frank Abdi, Ramakrishna T. Bhatt, and Joseph E. Grady. "Durability Modeling of Environmental Barrier Coating (EBC) Using Finite Element Based Progressive Failure Analysis." Journal of Ceramics 2014 (April 9, 2014): 1–10. http://dx.doi.org/10.1155/2014/874034.

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The necessity for a protecting guard for the popular ceramic matrix composites (CMCs) is getting a lot of attention from engine manufacturers and aerospace companies. The CMC has a weight advantage over standard metallic materials and more performance benefits. However, these materials undergo degradation that typically includes coating interface oxidation as opposed to moisture induced matrix which is generally seen at a higher temperature. Additionally, other factors such as residual stresses, coating process related flaws, and casting conditions may influence the degradation of their mechanical properties. These durability considerations are being addressed by introducing highly specialized form of environmental barrier coating (EBC) that is being developed and explored in particular for high temperature applications greater than 1100°C. As a result, a novel computational simulation approach is presented to predict life for EBC/CMC specimen using the finite element method augmented with progressive failure analysis (PFA) that included durability, damage tracking, and material degradation model. The life assessment is carried out using both micromechanics and macromechanics properties. The macromechanics properties yielded a more conservative life for the CMC specimen as compared to that obtained from the micromechanics with fiber and matrix properties as input.

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Czerwinski, F., and J. A. Szpunar. "Texture in Metallic and Ceramic Films and Coatings." Textures and Microstructures 32, no. 1-4 (January 1, 1999): 107–18. http://dx.doi.org/10.1155/tsm.32.107.

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The properties of films and coatings can be optimized for a variety of applications by modifying their texture. Understanding how the texture in thin films is formed and how it can be controlled during film growth process is one of the most important areas of texture research. Several examples were selected to illustrate how the texture in films and coatings is developed and to explain how various properties of films are affected by texture. In particular, texture development during electrodeposition of Zn-based automobile coatings, Ni and Ni-based layers for magnetic recording as well as Fe and Fe-based wearresistant coatings, is presented. A new area of application of texture research to control the high-temperature oxidation resistance of engineering materials is described. Using experimental data for Ni and Ti, the factors affecting texture formation during growth of ceramic oxides are discussed, with special attention paid to the role of substrate texture. The correlation between the oxide texture, grain boundary structure and diffusion of metal and oxygen ions at high temperatures, is considered.

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42

Zhang, Yingyi. "Strengthening, Corrosion and Protection of High-Temperature Structural Materials." Coatings 12, no. 8 (August 7, 2022): 1136. http://dx.doi.org/10.3390/coatings12081136.

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This Special Issue presents a series of research papers and reviews about the second-phase enhancement, surface coating technology, high-temperature corrosion, wear, erosion, and protection of high-temperature structural materials. The effects of alloying and surface coating technology on the microstructure, mechanical properties, and oxidation resistance of materials were systematically introduced. In addition, this Special Issue also summarizes the strengthening mechanism of the second relatively refractory metal alloy and carbonized ceramic materials, compares the advantages and disadvantages of different surface coating technologies, and analyzes the oxidation behavior and failure mechanism of the coating in order to provide valuable research references for related fields.

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Andreani, Anne-Sophie, Francis Rebillat, and Angéline Poulon-Quintin. "Oxidation Mechanism of ZrB₂-SiC Tested in a Solar Furnace above 2200°C." Advances in Science and Technology 65 (October 2010): 124–29. http://dx.doi.org/10.4028/www.scientific.net/ast.65.124.

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The solar furnace is a heating system based on concentrated sunrays on the material surface. It is an original method for testing ultra-high-temperature ceramics (UHTC) at very high temperature (above 2200°C) in air with an exposure time of several minutes. In this study, the solar flux is 15.5 MW.m-2 with a homogeneous exposed surface of 10 mm2. A large temperature-time composition parameters space is covered producing a large set of oxidized samples. Massive cylindrical specimens of UHTC materials are prepared by spark plasma sintering at 1900°C under a pressure of 100 MPa for 5 minutes. Then, samples are tested in air from 1750°C up to 2400°C with dwell times varied from 1 to 5 min. During oxidation of ZrB2-SiC (20%vol) material, the formed and known complex oxide scale identified from literature is easily reproduced using this method. It consists of a thin outer silica layer and zirconia columnar layer with a region of SiC depleted zone in ZrB2 phase. The impact of the reduction of Si content is quantified and the coating ZrB2-20%vol SiC is tested as protection on C-C composite.

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Kuznetsov, Yuri A., Aleksandr V. Kolomeichenko, Vladimir V. Goncharenko, and Igor N. Kravchenko. "Investigation of Internal Stresses in Thin Layer Oxide Coatings on Aluminum Alloys." Materials Science Forum 968 (August 2019): 153–60. http://dx.doi.org/10.4028/www.scientific.net/msf.968.153.

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Among physical and mechanic properties of coatings the internal stresses are of special interest. Internal stresses include stresses which exist and are counterbalanced within a rigid body in cases when there is no external action which caused them. In coatings obtained on the basis of nickel, chrome they can decrease the adhesive strength, cause cracking, peeling, anticorrosion properties deterioration. But the definite level of internal stresses leads to increase of hardness and coatings wear resistance and also facilitates porous coatings obtaining. The results of theoretical and experimental investigations of the internal stresses that appear in oxide ceramic coatings formed by plasma-electrolytic oxidation (PEO) on aluminum surfaces are presented.

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Xu, Zhen Hua, Li Min He, Feng Lu, and Ren De Mu. "Failure of the EB-PVD TBCs of Rare Earth Zirconates." Materials Science Forum 686 (June 2011): 561–68. http://dx.doi.org/10.4028/www.scientific.net/msf.686.561.

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Thermal barrier coatings (TBCs) have very important applications in gas turbines for higher thermal efficiency and protection of components at high temperature. TBCs of rare earth materials such as lanthanum zirconate (La2Zr2O7, LZ), lanthanum yttrium zirconate (3wt% Y2O3- La2Zr2O7, 3YLZ), lanthanum cerium zirconate (La2(Zr0.7Ce0.3)2O7, LZ7C3) were prepared by electron beam-physical vapor deposition (EB-PVD). The compositions, crystal structures, thermal expansion behaviors, cross-sectional morphologies and cyclic oxidation behaviors of these coatings were studied. These coatings have partially deviated from their original compositions due to the different evaporation rates of oxides, and the deviation could be reduced by properly controlling the deposition condition. The thermal expansion behavior of LZ coating can be largely improved after doping with 3wt% Y2O3 and CeO2. The excess La2O3, chemical incompatibilities of the ceramic coatings with thermally grown oxide (TGO) layers, the visible cracks initiation, propagation and extension, the abnormal oxidation of bond coat, and the thermal expansion mismatch between ceramic coatings and bond coat are the primary factors for the spallation of LZ, 3YLZ and LZ7C3 coatings.

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Costa Oliveira, Ana Claudia, G. Donato, R. Magnabosco, Viviane Teleginski, Daniele Cristina Chagas, Getúlio de Vasconcelos, and F. Camargo. "Analysis of the Metallurgical Bonding between Inconel and NiCrAlY Coatings by HVOF and with CO₂ Laser Beam." Materials Science Forum 869 (August 2016): 727–31. http://dx.doi.org/10.4028/www.scientific.net/msf.869.727.

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Coatings are applied on turbine blades’ surfaces to provide protection not only against high temperature but also against aggressive environment. Ceramic coatings are employed to avoid metallic substrate overheating, while at the same time increasing turbine work temperature and performance. A bond coat (BC) base of particulate material based on Ni-Al powders is necessary to assure oxidation protection, a good adhesion and gradual decrease in thermal expansion coefficient between the blades’ metallic substrate and the ceramic top coating. One of the most important parameters of such coatings is the adhesion strength. In this work, a NiCrAlY bond coat was deposited on Inconel 625 substrate employing High-Velocity Oxygen-Fuel (HVOF) thermal spraying technology and CO2 laser beam irradiation to enhance coating–substrate adherence and metallurgical bonding. Microstructural features were examined by optical and scanning electron microscopy (SEM), X-ray diffraction and microhardness analysis. The results indicate that the laser treatment provided an efficient metallurgical bond between the (BC) and Inconel 625 substrate.

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LI, H. X., R. G. SONG, and J. ZHAO. "EFFECT OF CURRENT INTENSITY ON THE PROPERTIES OF CERAMIC COATINGS FABRICATED BY MICRO-ARC OXIDATION." Surface Review and Letters 15, no. 06 (December 2008): 809–13. http://dx.doi.org/10.1142/s0218625x08011998.

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Ceramic coatings have been synthesized on 6063 aluminum alloy by micro-arc oxidation (MAO) technique. The effects of current intensity on the chemical and mechanical properties of MAO coatings have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-hardness test, adhesion measurement, and friction and wear tests. The fabricated samples consist mainly of α- Al 2 O 3 and γ- Al 2 O 3 phases. SEM results show that the surface of the prepared coatings is dense except some pores distributed over the coating surface. Mechanical measurements show that these kinds of samples have high hardness, excellent adhesion, and high friction resistance. The coating consists of a thin buffer layer at the metal surface followed by a relatively compact inner layer and finally a higher porous ceramic layer. Meanwhile, there is a nonuniform distribution of hardness for the samples in the plane parallel to the substrate.

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Kiryc, Markus, Norbert Kazamer, Deniz Kurumlu, and Gabriela Marginean. "Comparative Study on the Thermal Performance of Cr-CrxOy and YSZ-CoNiCrAlY Coatings Exposed at 900 °C." Materials 14, no. 20 (October 13, 2021): 6040. http://dx.doi.org/10.3390/ma14206040.

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Yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) deposited on CoNiCrAlY oxidation protective bond coats are commonly required in temperature regimes up to 1200 °C (e.g., hot gas turbine regions) due to their superior thermal behavior and mechanical properties. For temperatures up to around 900 °C, oxidation protection can be alternatively provided by metallic-ceramic Cr-CrxOy coatings. For the present research, Cr-CrxOy atmospheric plasma sprayed (APS) and YSZ-CoNiCrAlY APS-high velocity oxy-fuel TBC coatings were deposited on a NiCr20Co18Ti substrate. The samples were isothermally heat treated at 900 °C for 10 h in an environmental atmosphere and subsequently isothermally oxidized at the same temperature for 1200 h. Investigations of the physical, chemical, and mechanical properties were performed on the as-sprayed, heat-treated, and oxidized samples. The oxidation behavior, microhardness, cohesion, and adhesion of the samples were correlated with the microstructural investigations and compared to the conventional TBC system. It could be shown that heat treating decreased the Cr-CrxOy coatings crack susceptibility and led to the formation of a protective thermally grown Cr oxide layer. The experimental work on the YSZ-CoNiCrAlY system revealed that the phase composition of the bond coat has a direct influence on the oxidation protection of the coating system.

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Kiryc, Markus, Norbert Kazamer, Deniz Kurumlu, and Gabriela Marginean. "Comparative Study on the Thermal Performance of Cr-CrxOy and YSZ-CoNiCrAlY Coatings Exposed at 900 °C." Materials 14, no. 20 (October 13, 2021): 6040. http://dx.doi.org/10.3390/ma14206040.

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Yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) deposited on CoNiCrAlY oxidation protective bond coats are commonly required in temperature regimes up to 1200 °C (e.g., hot gas turbine regions) due to their superior thermal behavior and mechanical properties. For temperatures up to around 900 °C, oxidation protection can be alternatively provided by metallic-ceramic Cr-CrxOy coatings. For the present research, Cr-CrxOy atmospheric plasma sprayed (APS) and YSZ-CoNiCrAlY APS-high velocity oxy-fuel TBC coatings were deposited on a NiCr20Co18Ti substrate. The samples were isothermally heat treated at 900 °C for 10 h in an environmental atmosphere and subsequently isothermally oxidized at the same temperature for 1200 h. Investigations of the physical, chemical, and mechanical properties were performed on the as-sprayed, heat-treated, and oxidized samples. The oxidation behavior, microhardness, cohesion, and adhesion of the samples were correlated with the microstructural investigations and compared to the conventional TBC system. It could be shown that heat treating decreased the Cr-CrxOy coatings crack susceptibility and led to the formation of a protective thermally grown Cr oxide layer. The experimental work on the YSZ-CoNiCrAlY system revealed that the phase composition of the bond coat has a direct influence on the oxidation protection of the coating system.

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Góral, Marek, and Tadeusz Kubaszek. "The Influence of Process Parameters on Structure of Ceramic Coatings Deposited by PS-PVD Method." Solid State Phenomena 267 (October 2017): 243–47. http://dx.doi.org/10.4028/www.scientific.net/ssp.267.243.

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Thermal Barrier Coatings (TBC) is the most advanced system for protection of turbine blades and vanes against high temperature, and oxidation. They are used in most advanced jet engines. In present article the new Plasma Spray Physical Vapour Deposition Technology was used to obtain yttria stabilized zirconia oxide coating with columnar structure. In research the different process parameters were changed. It was observed that powder feed rate had big influence on coating thickness. The large amount of Ar in plasma gasses combined with high powder feed rate resulted in partial evaporation of ceramic powder and splat-type structure. The same effect was observed when the power current was decreased form 2400 to 1600 A as well as pressure was increased to 200 Pa when the powder feed rate was 30 g/min. The obtained results showed that full evaporation of ceramic powder requires very low feed rate of ceramic material (2 g/min), high power current and high He content into plasma.

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Journal articles on the topic 'Oxidation protection by thin ceramic coatings'

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