Nanoceramic Coatings Research Articles

Nanoceramic-based coatings for corrosion protection: a review on synthesis, mechanisms, and applications.

Corrosion is a pervasive issue with significant economic and safety implications across various industries. Nanoceramic-based coatings have emerged as a promising solution for corrosion protection due to their unique properties and mechanisms. This review aims to comprehensively examine the synthesis, mechanisms, and applications of nanoceramic-based coatings for corrosion protection. The review begins by highlighting the importance of corrosion protection and its impact on different industries. It introduces nanoceramic-based coatings as a potential solution to address this challenge. The objective is to provide a thorough understanding of the synthesis methods, mechanisms, and applications of these coatings. The fundamental principles of corrosion and different corrosion mechanisms are discussed, along with the limitations of traditional corrosion protection methods. The review emphasizes how nanoceramic-based coatings can overcome these limitations and provide superior corrosion resistance. Various synthesis methods, including sol-gel, electrodeposition, and physical vapor deposition, are described in detail, along with the factors influencing the synthesis process. Recent advancements and innovations in nanoceramic coating synthesis techniques are also highlighted. This looks at how coatings made with tiny ceramic particles protect against corrosion. It examines the importance of small-scale details like particle size, shape, and what the particles are made of. The formation of passive layers, self-healing mechanisms, and barrier properties of nanoceramic coatings are explained. The diverse applications of nanoceramic coatings for corrosion protection in industries such as automotive, aerospace, and marine are comprehensively discussed. Case studies and examples demonstrating the significant corrosion resistance and improved performance achieved with nanoceramic coatings are presented.

Characterization and Corrosion Behavior of Nano-ceramic Coatings Produced by MAO Method: The Role of Process Time

Characterization and Corrosion Behavior of Nano-ceramic Coatings Produced by MAO Method: The Role of Process Time

Microstructure and High-Temperature Properties of Cr3C2-25NiCr Nanoceramic Coatings Prepared by HVAF

The study examines the microstructure and high-temperature properties of Cr3C2-25NiCr nanoceramic coatings on 316H high-temperature-resistant stainless steel that were prepared by high-velocity air–fuel spraying (HVAF) technology. The micromorphology, phase composition, fracture toughness, high-temperature hardness, high-temperature friction, and wear properties of the coating were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), high-temperature Vickers hardness tester, high-temperature friction and wear tester, and surface profiler. The results show that the Cr3C2-25NiCr coating prepared by HVAF presents a typical thermal spraying coating structure, with a dense structure and a porosity of only 0.34%. The coating consists of a Cr3C2 hard phase, a NiCr bonding phase, and a small amount of Cr7C3 phase; The average microhardness of the coating at room temperature is 998.8 HV0.3, which is about five times higher than that of 316H substrate. The Weibull distribution of the coating is unimodal, showing stable mechanical properties. The average microhardness values of the coating at 450 °C, 550 °C, 650 °C, and 750 °C are 840 HV0.3, 811 HV0.3, 729 HV0.3, and 696 HV0.3 respectively. The average friction coefficient of the Cr3C2-25NiCr coating initially decreases and then increases with temperature. During high-temperature friction and wear, a dark gray oxide film forms on the coating surface. The formation speed of the oxide film accelerates with increasing temperature, shortening the running-in period of the coating. The oxide film acts as a lubricant, reducing the friction coefficient of the coating. The Cr3C2-25NiCr coating exhibits exceptional high-temperature friction and wear resistance, primarily through oxidative wear. The Cr3C2-25NiCr coating exhibits outstanding high-temperature friction and wear resistance, with oxidative wear being the primary wear mechanism at elevated temperatures.

Experimental and Numerical Analysis on a Thermal Barrier Coating with Nano-Ceramic Base: A Potential Solution to Reduce Urban Heat Islands?

Adopting a multiscale approach is crucial for optimizing urban and building performance, prompting inquiries about the link between a technology’s local efficiency (building scale) and its broader impact (city-wide). To investigate this correlation and devise effective strategies for enhancing building and city energy performance, we experimentally examined a commercial nano-ceramic Thermal Barrier Coating (TBC) on a small-scale building and assessed numerically its influence on mitigating Urban Heat Islands (UHIs) at a city scale, translated in our case by the use of the thermal comfort index: the Universal Thermal Climate Index (UTCI). Our results reveal that the coating significantly curbs heat transfer locally, reducing surface temperatures by over 50 ∘C compared to traditional roofs and attenuating more than 70% of heat flux, potentially alleviating air conditioning demands and associated urban heat effects. However, implementing such coatings across a city does not notably advance overall efficiency and might trigger minor overheating on thermal perception. Hence, while nano-ceramic coatings indirectly aid UHI mitigation, they are not a standalone fix; instead, an integrated strategy involving efficient coatings, sustainable urban planning, and increased vegetation emerges as the optimal path toward creating enduringly sustainable, pleasant, and efficient urban environments to counter urban heat challenges effectively.

Effect of nano-ceramic coating on surface property and microbial adhesion to poly(methyl methacrylate).

To improve surface properties of poly(methyl methacrylate) (PMMA) using nano-ceramic coatings and assess microbial adherence after long-term use of a chemical cleanser. Thirty-six PMMA samples were fabricated, polished and coated with a nano-thin TiO2 or mixed TiO2 /ZrO2 , with uncoated samples as controls. Six samples in each group (n=12) were soaked in Polident denture cleaner 180 times for 30 min, while six were soaked in deionized water. Surface roughness of PMMA before and after being soaked in Polident was assessed. All samples were subsequently exposed to Candida albicans for 6h and the adherent cells were determined by viable colony count. Two-way analysis of variance was performed for statistical analysis. No significant difference in surface roughness was noted between the uncoated and coated PMMA before soaking. After soaking, surface roughness of the uncoated PMMA increased from 0.164 to 0.532 μm (p < .05). No significant change was observed for TiO2 -coated (0.105-0.143 μm) or TiO2 /ZrO2 -coated PMMA (0.104-0.141 μm). Attachment of C. albicans to PMMA soaked in water showed significantly less attachment to both TiO2 -coated (1.4 × 103 cfu/ml) and TiO2 /ZrO2 -coated PMMA (1.6 × 103 cfu/ml) than to the uncoated PMMA (2.6 × 103 cfu/ml). After soaking in Polident, the uncoated PMMA had significantly less C. albicans attachment than coated samples. Less attachment was noted on the TiO2 /ZrO2 -coated PMMA then the TiO2 -coated samples (p < .05). Nano-ceramic TiO22 /ZrO2 coating of PMMA denture base material alters surface properties thus reduces oral microbial adhesion. It represents a promising alternative to the chemical disinfection for PMMA denture materials.

Design of a PLD–grown Y2O3 protective barrier for fusion relevant applications

Advanced and innovative solutions are currently under investigations in order to solve the long-standing issues of materials constituting the breeding blanket of a future fusion reactor. Tritium permeation through steels, corrosion perpetrated by the breeding media, magnetohydrodynamic (MHD) effects and intense neutron irradiation hinder the realization of this technology. Recently, the employment of protective nanoceramic coatings has been considered as one of the few viable solutions. In particular, the pulsed laser deposition (PLD) technique allows to produce dense, compact and uniform coatings, which are the fundamental characteristics when designing a protective barrier. Yttrium oxide (Y2O3) is one of the most promising candidates given its superior stability when facing lithium-based heavy liquid metals and also its low nuclear activation yield, thus it was selected as subject of study and characterzation. PLD-grown Y2O3 coatings were then tested in order to assess their feasability as protective barriers at blanket relevant conditions. Basic characterization of the as deposited and annealed (450 °C) films was perfomed (scanning electron microscopy, atomic force microscope, grazing incident angle x-rays diffraction, nanoindenation). A coated sample was also exposed to static Pb-16Li at.% for 1000 h, showing optimal corrosion resistance and thermal stability at high temperature (550 °C). Finally, the electrical resistivity of this material was measured (up to 200 °C) in order to evaluate its ability to mitigate the MHD detrimental effects. To conclude, a preliminary characterization of the PLD-grown Y2O3 coatings proved the possibility to employ them as multifunctional protective barrier to enable the accomplishment of the breeding blanket technology.

Water management implications for ALD-modified polymer electrolyte membrane fuel cell catalysts

Device testing of polymer electrolyte membrane fuel cell catalysts is essential for electrocatalyst development, yet most reported catalysts fabricated with nanoceramic coatings via atomic layer deposition (ALD) have not been thoroughly examined in this fashion. Platinum nanoparticle catalysts supported on functionalized XC72 carbon black that had been modified with sub-monolayer WN films and subjected to various thermal treatments were incorporated into membrane electrode assemblies and tested for oxygen reduction reaction activity in a fuel cell. The mass activities of the catalysts calculated at low current densities had comparable trends to those previously recorded in aqueous half-cell testing; however, significant deviations in catalyst performance became apparent at high current densities in the mass transport region of the polarization curves. The poor performance of the ALD-modified catalysts was attributed to water flooding induced by the low hydrophobicity of these catalyst layers, as determined by contact angle measurements on the cathode surfaces. It was seen that hydrophobicity was increased by thermal treatment and removal of surface groups known to be prone to hydrogen bonding, thereby improving the catalyst performance in the mass transport region. A heat-treated WN-coated ALD catalyst was found to have superior performance to commercial Pt/C. The field of research on fuel cell catalyst design via ALD is rapidly expanding, and this work demonstrates the importance of understanding the impact of ALD-deposited nanostructures on materials properties beyond the pure electrocatalytic activity.

Corrosion resistance evaluation of carbon steel plates protected by zirconium and titanium nanoceramic coatings

Metal surface pre-treatment is a known process and is used to increase corrosion performance as well as improve adhesion between the substrate and the paint layer. The present paper evaluated the corrosion resistance of carbon steel before and after treatment with nanoceramic coatings. The comparison was between a pure zirconia nanoceramic compound (Bonderite NT-1), with the addition of a dispersant (polyacrylic acid) and another nanoceramic coating developed from titanium oxide. Additionally, salt spray, open circuit potential (OCP), polarization and impedance tests were performed to obtain a methodology to quantitatively assess the quality of protection. The zirconia coating presented superior characteristics than the corrosion protection. The corrosion potential of this coating was about twice as low as the others. The addition of dispersant produced no significant improvements in corrosion resistance and was similar to uncoated carbon steel, possibly due to the high concentration used.

Recent studies on thermodynamic processes in nano-ceramic thermal insulation coatings

Among nanotechnology-based thermal insulation materials thermodynamic performance of nano-ceramic coatings generates intensive discussions. Complete agreement has not been found yet about the mecha...

Multifunctional nanoceramic coatings for future generation nuclear systems

Several breeding blanket concepts for the DEMO reactor employ the eutectic Pb–16Li as breeder material, namely Helium Cooled Lithium Lead (HCLL), Water Cooled Lithium Lead (WCLL) and Dual Coolant Lithium Lead (DCLL). These three concepts share, with different incidences, three major technological challenges: Tritium containment, steel corrosion and magnetohydrodynamic drag. Here, we describe the ongoing work on multifunctional Al2O3 nanoceramic coatings grown by Pulsed Laser Deposition (PLD) on Reduction-Activation Ferritic-Martensitic (RAFM) steel. In fact, PLD can produce relatively thick (up to tens of μm) high performance coatings with metal-like mechanical properties. The coatings were tested as Tritium permeation barriers with Hydrogen at different temperature (from 350 to 650 °C). Results collected in this way indicate an excellent behavior, with a permeation reduction factor (PRF) close to 105. In addition, it was shown that they are able to maintain similar properties even when Deuterium was employed and also under 2 MeVelectrons irradiation. [1] Moreover, the electrical conductivity of these dielectric coatings was shown to be extremely low even under irradiation. Finally, to evaluate the chemical compatibility of Al2O3 films in liquid eutectic Pb-16Li, PLD deposited samples have been exposed to static corrosion tests up to 8000 h. No corrosive attacks of the steel substrate are detected. To conclude, Alumina coatings deposited by PLD show optimal characteristics in order to tackle the major technological challenges associated to the Breeding Blanket (BB) concepts employing Pb-16Li as breeder materials.

Thermal analysis of Nano ceramic coated piston used in natural gas engine

Nano ceramic coatings have low thermal conductivity which can provide good heat insulation properties, and therefore they have been widely used in industrial design as thermal barrier coatings (TBCs). In the design of internal combustion engines, TBCs have been used on combustion chamber components to improve engine performance. In this paper, improvement in the working performance of natural gas engines is demonstrated when an aluminum alloy piston is sprayed with a Y2O3 partially stabilized zirconia (PYSZ) ceramic coating. Steady-state thermal analyses were used to determine the effects of the ceramic coating on temperature distributions. Output was compared with results from an uncoated conventional piston using the finite element method. Results show that the temperature at the top surface of coated piston is significantly higher (about 44% or 153 °C higher) than that of the uncoated piston. This higher combustion chamber temperature results in better engine thermal efficiency and lower emissions. Simultaneously, the temperature of the coated piston substrate is much lower (about 12% or 43 °C lower) than that of the uncoated piston. The lower metallic substrate temperature provides better thermal fatigue protection for the piston.

Moisture Behavior of Thermal Insulation Coating Consisted of Vacuum-Hollow Nano-Ceramic Microspheres

Nanotechnology-based thermal insulation materials have appeared in building industry in the last two decades. Among them thermal insulating coatings consisted of vacuum-hollow nano-ceramic microspheres are the subjects of most professional discussion. Most studies about these coatings focus only on examination of thermodynamic properties, because there is still no consensus in academic circles about thermodynamic processes inside nano-ceramic coatings. These professional discussions distract attention from other unknown but also important material properties, like behavior by contact with moisture. This paper summarizes the results of moisture behavior tests with nano-ceramic thermal insulation coatings which were conducted to determine the time trend of water absorption, as well as volume, mass and thermal insulation quality changes caused by increasing moisture content. Analyzing the results mathematical connections were found to describe the relation between water content, dimensional and thermal conductivity changes.

Series of Experiments with Thermal Insulation Coatings Consisted of Vacuum-Hollow Nano-Ceramic Microspheres

Because of the rigorous regulations in the 21st century it has become a serious task for designers to find more effective ways for thermal insulation. One of these options is the application of nanotechnology-based materials. Among nano-scale structured materials the most uncertainties are found about the thermal insulating quality of thermal insulation coatings consisted of vacuum-hollow nano-ceramic microspheres. Complete agreement had not been already found about the mechanism of their insulating effect. In order to explore and describe the thermodynamic process inside nano-ceramic coatings (NCC) 6 series of heat transfer resistance experiments were performed in 2014-2017. Several building structure configurations with 12 different orders of layers were tested with a standard heat flow meter. On basis of these results it could be concluded that in case of nano-structured materials convective heat transfer coefficient might be taken account in different way than in case of traditional macro-structured thermal insulation materials.

Corrosion and radiation resistant nanoceramic coatings for lead fast reactors

Bare and Al2O3-coated austenitic steel samples are exposed to lead-fast-reactor relevant corrosive conditions. Selective leaching of Ni, Mn and Cr is observed in bare samples exposed to high temperature stagnant lead (550°C, 10−8wt.% oxygen, 1000 and 4000h). By contrast, corrosion is not observed in either pristine (4000h) or irradiated (1000h) coated samples. Further characterization and testing methods include SEM, TEM, STEM, EDS, cyclic nanoimpact, microindentation, scratch, and thermal cycling. Overall, the results show that the coatings retain structural integrity under the conditions investigated, which is a crucial prerogative for corrosion protection with ceramic coatings.

Binary and Ternary Nanoceramic Coatings to Protect Carbon Steel in Artificial Seawater

Binary and Ternary nanoparticles coatings have been applied on carbon steel using atomization method (cold spraying) to corrosion control in seawater. Nanoparticles were included Nano Al2O3, SiC and ZrO2. The characterization of coated surfaces has been investigated by AFM and SEM in addition to calculate the coating thickness. The binary coatings deal with 50%Al2O3-50%SiC, 50%Al2O3-ZrO2 and 50%SiC-50%ZrO2, while the ternary coating was 60%Al2O3-20%SiC-20%ZrO2. The results showed that 50%Al2O3-50%SiC had the lowest thickness and most uniform distribution in AFM and SEM due to closing in particle sizes. Corrosion test achieved to estimate the corrosion resistance, protection efficiency and porosity percentage which indicated the role of Nano particle coating to corrosion control. These data showed that the Nano 50%Al2O3-50%SiC coating had the most noble corrosion potential, lowest corrosion current density (lowest corrosion rate), highest corrosion resistance, highest efficiency 99.651 % and lowest porosity percent 1.438×10-11. Cyclic polarization also estimated to show the probability for pitting corrosion. The coating with 50%Al2O3-50%SiC gave the highest breakdown potential equal to +69mV.

Reactive-sputter-deposited β-Ta 2 O 5 and TaON nanoceramic coatings on Ti–6Al–4V alloy against wear and corrosion damage

Abstract In this study, two different types of nanoceramic coatings; namely, β-Ta2O5 and TaON, were synthesized by double glow discharge plasma technique on Ti–6Al–4V alloy to improve its wear and corrosion resistance. The new coatings were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The two coatings were found to have a thickness of about ~ 25 μm and exhibit similar microstructural characteristics, i.e., composed of equiaxed grains with an average grain size of ~ 15 nm. They are tightly adhered to the Ti–6Al–4V substrate. Nanoindentation was used to determine the hardness and elastic modulus of the two coatings and the adhesion strength between the coatings and substrate was also evaluated by scratch testing. Dry sliding wear tests were performed using a ball-on-disk type tribometer, in which the two coatings were slid against Si3N4 ceramic balls under applied loads ranging from 2.3 N to 5.3 N at room temperature. Compared with the Ti–6Al–4V, the coated samples showed a decrease of two orders of magnitude in the specific wear rate, and the specific wear rates of the two coatings were also insensitive to the applied normal loads. The electrochemical behavior of the two coatings was characterized by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and Mott–Schottky analysis in a naturally aerated 5 wt.% HCl solution. While both types of coatings were able to greatly improve the corrosion resistance of Ti–6Al–4V alloy, the TaON coating exhibit a higher corrosion resistance than the β-Ta2O5, due primarily to the TaON coating with a lower carrier density.

Evolution of the Requirements for Anticorrosion Protection of Road and Bridge Infrastructure

Many industries all over the world have special, sector-specific requirements concerning anti-corrosion protection. This contributes to large savings in corrosion-related costs, which account for about 6% of the Gross Domestic Product in developed countries. In 1999, the General Directorate for Public Roads published, for the first time in Poland, its requirements concerning the application and acceptance of anti-corrosion coatings for steel components of road and bridge structures. They were updated in 2006. In 2010, the military department of the General Directorate for National Roads and Motorways issued anti-corrosion instructions applicable to assemblable bridge structures stored as part of the military mobilization reserves of the State. The General Directorate decided to publish them due to the openwork design of these structures and the unusual conditions of their use and storage. In 2013, the Road Management Authorities in Warsaw commissioned a catalogue of anti-corrosion technologies for structures made of thin-walled sections or sheet metal with a thickness of up to 3mm. In particular, the catalogue focuses on highly durable anti-corrosion coatings for metal constructions of noise barriers. All these documents have been developed by the Road and Bridge Research Institute. As set out in the first two of these documents, the maximum duration of anti-corrosion protection is 15 years, in conformity with ISO 12944. The last document provides for anti-corrosion coatings with durability of over 25 years. It also pays more attention to aesthetic qualities of anti-corrosion coatings, whose colour may not change in a noticeable way during the first 10 years of their use (ΔE <2, while the reduction of gloss may not exceed 20%). The new coating materials are based on resins that have never been used before, such as polysiloxane resins, polyfluorinated resins, polyurea resins, new fillers and pigments. Modern, eco-friendly powder coatings (including paints with the zinc fillers) are also being used on an ever-increasing scale, especially for outdoor applications of high durability. Other new generation products include conversion coatings, which improve the adhesion and durability of systems, as well as nano-ceramic coatings, self assembling molecules, baths based on transitional metal compounds with complex-forming properties such as titanium and zirconium (also with polymers), etc. Application of these materials makes it necessary to use more and more sophisticated inspection methods and devices. This creates new requirements for professionals, from the designer and the investor to contractors and inspectors, who all need to be well aware of corrosion-related issues.The analysis of these documents focus on the development of anti-corrosion materials and anti-corrosion protection technologies. Any documents of this type must be constantly revised to keep an owner up to date with modern solutions.

A new strategy based on thermodiffusion of ceramic nanopigments into metal surfaces and formation of anti-corrosion coatings

The present paper is the first report about preparation of anti-corrosion coatings based on thermodiffusion of ceramic nanopigments into metal surfaces. At first, Cr1.3Fe0.7O3 ceramic nanopigments have been synthesized by simple and environmentally benign sol–gel method. Annealing of the gels at different temperatures ranging from 600 to 1000 °C yielded the pure rhombohedral structure. The structural evolutions and microstructural characteristics of the synthesized nanoceramics were investigated through different methods containing X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Then Cr1.3Fe0.7O3 ceramic nanopigments were coated on mild steel surface via thermodiffusion method. The surface morphology and the corrosion behavior of the Cr1.3Fe0.7O3 coatings were evaluated using atomic force microscopy (AFM), field-emission scanning electron microscopy (FE-SEM), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements in a solution of 2.0 M HCl. It is found that morphology of diffusion coatings affects the protective properties of mild steel. On the other hand, in extra-corrosive HCl media Cr1.3Fe0.7O3 nanoceramic coatings provide mild steel with high protective properties.

Surface characteristics, corrosion resistance and MG63 osteoblast-like cells attachment behaviour of nano SiO2–ZrO2 coated 316L stainless steel

Nano ceramic coatings were produced on to 316L SS. MG-63 osteoblast like cells attachments were good for silica containing coatings.

Promoting bone-like apatite formation on titanium alloys through nanocrystalline tantalum nitride coatings.

The study aims to advance the applicability of titanium alloys as bone implant materials by tackling some important aspects of surface robustness and bioactivity. To do so, biologically active Ta-N nanocrystalline coatings were engineered on Ti-6Al-4V alloy substrates by reactive sputter deposition using a double glow discharge plasma technique. The surface morphology, phase composition and structure of the coatings were characterized using atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The newly developed coatings are extremely dense, adherent and composed of a cubic TaN phase and a minor fraction of hexagonal Ta2N phase. The microstructure of Ta-N coatings consists of nanocrystallites of about 15-20 nm in diameter, having a strong TaN(200)-oriented texture. Moreover, the coatings exhibit a uniform nanopillar structure on the surface, critical for the observed bioactivity. Scratching tests were performed to evaluate the adhesion strength between the Ta-N coatings and Ti-6Al-4V alloy substrates. The Ta-N coatings were found to exhibit a high scratch resistance and are thus suitable for load-bearing applications. The apatite-inducing ability of the coatings was evaluated in vitro using a simulated body fluid (SBF) that has almost equal compositions of inorganic ions to human blood plasma. After soaking in the solution for up to 14 days, only a few apatite particulates were observed on the surface of untreated Ti-6Al-4V alloy. By contrast, the surface of the Ta-N coatings was completely covered by a compact, AB-type apatite layer free of micro-cracks. High resolution transmission electron microscopy (HRTEM) observations reveal that after soaking for 14 days, the apatite layer, formed through a biomimetic process, comprises closely packed, needle-shaped apatite crystals of 34.5 ± 12.4 nm in length and 6.0 ± 0.2 nm in width. Moreover, nanotwins were identified in apatite, reminiscent of those found in bone minerals. The negatively-charged surface, combined with a unique surface structure of the Ta-N nanoceramic coatings, is believed to be responsible for the formation of a homogenous, compact bone-like apatite layer. The Ta-N nanoceramic coatings are expected to find applications as an integral part of biomaterials used in bone repair and replacement.