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High temperature vulcanization silicone rubber with hydrophobic–uvioresistant composite coating built by stepwise spray method showed a micro-nano structure and displayed the favorable hydrophobicity and ultraviolet shielding capability.

In this study, developing a composite coating on the surface of a biodegradable Mg–5Zn alloy using friction stir process (FSP) is the goal to control biodegradation of the alloy. The experimental procedure starts with the alloy casting, followed by homogenization treatment. Rotational speeds of 800, 1000, and 1250 rpm and 1, 2, and 3 passes using hydroxyapatite (HA) powder are utilized to develop Mg–5Zn/HA composite coating on the surface of the alloy. Microstructure of the as-cast Mg–5Zn alloy and Mg–5Zn/HA composite coating is characterized. Biodegradation behavior of the as-cast and coated alloy is also assessed in simulated body fluid using electrochemical potentiodynamic polarization and impedance spectroscopy tests. The results show that FSP can always modify the surface layer through the dynamic recrystallization process, leading to at least 35% decrease in corrosion rate of the alloy. The potentiodynamic polarization curves of the alloys disclose a break, indicating the impact of passivating behavior. The results also reveal that the rotation speed of 1000 rpm, with the increase in the number of passes, generates more refined microstructure on the surface of Mg–5Zn alloy, which improves its corrosion resistance with decreasing the corrosion rate of the alloy from 28.64 mpy to 0.27 mpy after FSP for three passes at 1000 rpm. In contrast, FSP with the rotation speed of 800 rpm and one pass, besides providing the refined microstructure, develops better distribution of hydroxyapatite particles on the surface, which results in the highest corrosion resistance among the FSPed Mg–5Zn/HA composite coated alloy.

Adding an anti-corrosion coating to the surface of magnesium (Mg) alloy is an effective means to improve its corrosion resistance, but it is particularly important to enhance the bonding force between the anti-corrosion coating and the Mg matrix. Epoxy resin coating is considered the most cost-effective approach from an industrial standpoint, while the hindering the wider utilization of Mg alloys with epoxy coating in the realm of engineering materials are due to their insufficient adhesion between Mg matrix and the epoxy coating. Here, we demonstrated a simple method for forming an epoxy resin/mineralized film composite coating. The mineralized products coatings were applied to the surface of Mg-3Nd alloy, via a direct reaction between Mg and 15 wt% Na2CO3 solution. Due to the inherent lamellar structure of alkaline magnesium carbonate mineralization film, the mechanical interlocking between the epoxy resin and the Mg substrate are remarkably strengthened. Therefore, this simple surface treatment method is promising to improve the adhesion between the epoxy resin and the matrix. Moreover, the effects of mineralized products coating on the corrosion resistance of Mg with epoxy coating were researched. It was observed that the corrosion resistance of Mg alloy with composite coatings are significantly enhanced. Such an investigation aims to provide a new method for developing a cost-effective and robust epoxy resin/mineralized film composite coating protection structure of Mg alloys in practical applications.

The wear and corrosion properties of the cyclone separator play a crucial role for the preparation of high-purity trichlorosilane in the Siemens method polysilicon cold hydrogenation system. In this work, we used fluent simulation technology to determine the optimal spraying process parameters of high velocity oxy-fuel (HVOF) technology, and the Ni60-WC composite coatings with different content of Cr3C2 were prepared on 316L stainless steel surface by using HVOF technology. The microstructure, phase structure and mechanical properties of the coating were characterized, and the wear resistance and corrosion resistance of the coating were studied. By comparing the friction coefficient, wear rate, wear profile and electrochemical polarization and impedance spectrum of the coating, the effects of Cr3C2 content on the microstructure, hardness, wear resistance and corrosion resistance of HVOF sprayed WC composite coating were studied. The results show that the coating prepared by using the simulation parameters are uniform and compact, the coating is tightly bonded to the substrate. The main phases in the coating are WC, W2C and Cr3C2. With the increase of Cr3C2 hard phase, the wear resistance and corrosion resistance gradually improve. Ni60–35WC–20Cr3C2 and Ni60–35WC–30Cr3C2 volume loss rate is the lowest, the friction depth is the shiniest, compared with the substrate, the wear rate is reduced by more than 95 %. Ni60–35WC–20Cr3C2 has the highest corrosion potential, the smallest corrosion current, the smallest corrosion rate and the largest impedance spectrum radius. However, when the content of Cr3C2 reaches 30 %, the corrosion resistance is the worst. Combined with wear resistance and corrosion resistance analysis, the Ni60–35WC–20Cr3C2 coating is selected to provide support for upgrading and prolongating the service life of the cyclone separator.

In this work, the (10 wt%, 30 wt%, 50 wt%) TiC reinforced AlFeCrCo medium entropy alloy (MEA) lightweight composite coatings with the extremely low porosity were successfully fabricated on Mg alloy substrate by resistance seam processing. The results showed that the microstructure of composite coating was consisting of a BCC-based MEA matrix and TiC particles, and a good metallurgical bonding with a semi-coherent relationship was formed between the coating and Mg alloy. Furthermore, the lightweight composite coatings (5.6–6.5 g cm−3) showed improved corrosion resistance over Mg alloy substrate. Specifically, the composite coatings exhibited optimized wear performance in the dry, deionized water and 3.5 wt% NaCl solution conditions with the increasing TiC content, surpassing related high/medium entropy alloy coatings, which is attributed to the formation of a coherent interface between the MEA matrix and the TiC particles. The first-principles calculations were performed to elucidate the nature for the higher bonding strength of TiC/MEA interface. In these wear conditions, the main wear mechanisms of composite coatings were discussed in terms of adhesive wear, oxidative wear and/or corrosive wear, in connection with their microstructure features and electrochemical behaviors. Based on the elevated anti-corrosion ability, this work has provided a strategy to fabricate advanced coatings on Mg alloys endowing with lower density, interfacial metallurgical bonding and optimized wear resistance, substantially contributing to the development of high-performance composite coatings.

This study aims to enhance the surface toughness and overall performance of arc-shaped nail teeth, which are vital components of presowing film-recovery machinery. Laser cladding technology was employed to deposit Ni60A/Cr 3 C 2 composite coatings with the rare-earth oxide Y 2 O 3 onto 60Si 2 Mn steel surfaces. The effects of different amounts of Y 2 O 3 on the wear resistance of Ni60A/Cr 3 C 2 composite coatings were evaluated. Scanning electron microscopy (SEM), X-ray diffraction, X-ray photoelectron spectroscopy, and 3D morphological analysis were used to investigate the microstructure, microhardness, elemental distribution, and tribological properties of the coatings. The ideal amount of Y 2 O 3 to add to the mixtures to enhance the wear resistance was determined. The results showed that the coating containing 1.5% Y 2 O 3 and Ni60A/Cr 3 C 2 composite powder exhibited superior overall performance. Coatings with different amounts of added Y 2 O 3 exhibited similar phase compositions, mainly consisting of γ-Ni-based, Ni 2 Si, M 7 C 3 (M = Cr, Mn), and M 23 C 6 -strengthened phases. SEM analysis revealed that the coating with 1.5% Y 2 O 3 exhibited excellent metallurgical bonding with the substrate. In addition, the coating exhibited finer grains, increased density, a more uniform distribution of coating elements, and a microhardness of 990 HV. Fewer grooves and smoother abrasions were observed after the wear test. The wear amount and depth were 14 × 10−4 g and 8.97 μm, which were 22.2% and 55.4% lower than the coating without added Y 2 O 3 , respectively. The tribological behavior indicated that adding the appropriate amount of Y 2 O 3 facilitated the grain boundary consolidation while enhancing the adhesive properties of the oxide film, thereby increasing the wear resistance of the coating. [ABSTRACT FROM AUTHOR]

Zinc (Zn) distinguishes itself as an excellent candidate for temporary orthopaedic implants due to its advantageous corrosion rate compared to other biodegradable metallic materials like Mg and Fe. The present research involved the fabrication of a porous, corrosion-resistant, and biocompatible plasma electrolytic oxidation (PEO) coating on a Zn–1Mg alloy. Bioactivity was imparted to the PEO coating by incorporating hydroxyapatite (HA) and silver-incorporated hydroxyapatite (SHA) nanoparticles into it by synergising the PEO process with electrophoretic deposition (EPD) in a single step. FESEM and EDS are utilised to confirm the porous PEO oxide layer formation and its sealing by HA and SHA particles in PEO-EPD coating. The coatings' phase composition, surface roughness, scratch resistance, and wettability were evaluated to assess their suitability for temporary implant applications. The coatings' wettability and roughness significantly improved compared to the untreated substrate, rendering it suitable for orthopaedic implant applications. The scratch resistance of the PEO coating was satisfactory and showed additional improvement in the thicker film with lower porosity, achieved through the combined PEO-EPD process. The electrochemical corrosion test in biological media revealed that the PEO coating enhanced the degradation resistance of Zn–1Mg, which was further enhanced by incorporating HA and SHA particles into the PEO coating. The in-vitro bioactivity test in simulated body fluid (SBF) and cytotoxicity test using L929 (Mouse fibroblast) cells proved that adding HA made the fabricated PEO coating biologically more favourable. Furthermore, the SHA-incorporated PEO coating is antibacterial against E. coli bacterial strains, enabling protection against post-implantation infections. • ZnO-HA ceramic composite coating developed on Zn–1Mg by PEO. • ZnO-HA coating showed 3 orders lower i corr compared to bare alloy. • Ceramic-composite coating proved to be bioactive and biocompatible. • Silver-incorporated coating exhibited the bactericidal property. [ABSTRACT FROM AUTHOR]

The corrosion behavior of electrodeposited nickel-based coatings with W, Mo, and TiOx as potential catalytic material for hydrogen evolution reaction (HER) in highly aggressive media, 0.5 M H2SO4 and 6 M KOH, is presented. A wide range of electrochemical and spectroscopic methods have been used, such as linear sweep voltammetry, open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) to characterize the coatings before and after a residence time of 336 h in the model corrosion environment. The NiW alloy and the NiWTiOx composite coating demonstrate the best corrosion resistance in an acidic environment due to the stable tungstate phase formation (H0.33O3W and H2O4W) on the surface. In alkaline environments, all the systems studied show enviable resistance, but the alloys containing molybdenum stand out. [ABSTRACT FROM AUTHOR]

Multifunctional interfacial layers and porous Zn surface as well as the introduction of electrolyte additives were achieved via a N, B doped carbon bubble-loaded iodine-assisted method, thus allowing the INBC@Zn electrode to exhibit superior cycling stability. [Display omitted] • A trinity composite coating is constructed by N, B doped carbon-loading iodine method. • ZnO interfacial layer, ZnI 2 additives and 3D porous structure are in-situ achieved. • ZnO interfacial layer and 3D porous structure modulate the uniform zinc deposition. • The INBC@Zn anode has excellent cycle stability and low nucleation overpotential. Although aqueous zinc ion batteries (AZIBs) have the merits of environmental friendliness, high safety and theoretical capacity, the slow kinetics associated with zinc deposition and unavoidable interfacial corrosion have seriously affected the commercialization of aqueous zinc ion batteries. In this work, an ingenious "trinity" design is proposed by applying a porous hydrophilic carbon-loaded iodine coating to the zinc metal surface (INBC@Zn), which simultaneously acts as an artificial protective layer, electrolyte additive and anode curvature regulator, so as to reduce the nucleation overpotential of Zn and promote the preferential deposition of (0 0 2) planes to some extent. With this synergistic effect, INBC@Zn exhibits high reversibility and strong side reaction inhibition. As a result, INBC@Zn shows high symmetric cycling stability up to 4500 h at 1 mA cm−2. An ultra-long cycle stability of 1500 cycles with high Coulombic efficiency (99.8 %) is achieved in the asymmetric cell. In addition, the INBC@Zn//NVO full cells exhibit impressive capacity retention (96 % after 1000 cycles at 3 A/g). Importantly, the designed pouch cell demonstrates stable performance and shows certain prospects for application. This work provides a facile and instructive approach toward the development of high-performance AZIBs. [ABSTRACT FROM AUTHOR]

Ni-based VC and TiVC 2 composite coatings were prepared on the surface of worn brake discs by laser direct deposition, and the influence mechanism of trace TiC addition on the microstructure and performance of the coating was investigated. The microstructure of the coatings was analyzed by XRD, SEM, EDS, and TEM, which revealed the evolution mechanism of the microstructure during the laser deposition process. The friction wear performance was tested on friction wear equipment. The results showed that VC 0.88 was formed by the in-situ reaction of C and V under the action of the laser, which presents dendritic morphology. After the addition of TiC particles, TiVC 2 was further synthesized along the TiC particles in addition to dispersed VC 0.88 in the coating. It can be seen that the addition of trace TiC particles inhibited the formation of VC 0.88 dendrites and enhanced the plastic toughness of the coating. HRTEM calibration proved the existence of TiVC 2 and Ni, and there was no obvious orientation relationship between the interface. The friction coefficients of Ni-based VC and Ni-based TiVC 2 coatings with Al 2 O 3 balls were 0.59 and 0.51 at room temperature, respectively. After 1.5 h of high-temperature wear at 300 °C and 600 °C, the distribution of wear marks shows a groove and high-temperature fatigue appearance. The TiC-doped coating has better wear properties than the base material and the original coating is expected to meet the requirements for brake discs. [ABSTRACT FROM AUTHOR]

Magnesium alloys have poor wear and corrosion resistance, which limits their wider industrial applications. In order to improve wear and corrosion resistance, Al–Al 2 O 3 –Cr 2 O 3 composite coatings with different Al, Al 2 O 3 and Cr 2 O 3 compositions were prepared on magnesium alloy substrate using supersonic plasma spraying technology. The surface morphology, porosity, and microstructure of Al–Al 2 O 3 –Cr 2 O 3 coatings were analyzed. The wear and corrosion resistance of Al–Al 2 O 3 –Cr 2 O 3 coatings were evaluated. The results showed the surface morphology of the composite coating was flat, and the cross-sectional structure had a layered structure with close interlayer bonding, and also the structure was uniform and fine. The A 70 A 15 C 15 coating exhibited the lowest porosity (0.56 %), whereas the porosity of A 30 A 35 C 35 coating was the highest (only 1.61 %). The wear resistance of the composite coating increased with increasing Al 2 O 3 –Cr 2 O 3 compositions, and the A 30 A 35 C 35 coating showed the best wear resistance, with a 90.58 % reduction in volume wear rate when compared with that of the magnesium alloy substrate. Based on electrochemical impedance spectroscopy testing, the A 50 A 25 C 25 coating had the slowest corrosion rate and best electrochemical corrosion resistance. Therefore, the preparation of the Al–Al 2 O 3 –Cr 2 O 3 coating by supersonic plasma spraying on magnesium alloy substrate is a promising technique for improving its wear and corrosion resistance. [ABSTRACT FROM AUTHOR]

A method has been proposed for creating an operationally durable copper coating with antimicrobial properties for the buttons of electrical switches based on the gas dynamic spray deposition of copper on acrylonitrile butadiene styrene (ABS) plastic. It is shown that during the coating process, a polymer film is formed on top of the copper layer. Comparative in situ studies of microbial contamination have shown that the copper-coated buttons have a significant antimicrobial effect compared to standard buttons. Analysis of swabs over a 22-week study in a hospital environment showed that the frequency of contamination for a copper-coated button with various microorganisms was 2.7 times lower than that of a control button. The presented results allow us to consider the developed copper coating for plastic switches an effective alternative method in the fight against healthcare-associated infections. [ABSTRACT FROM AUTHOR]

Developing photothermal anti/deicing fluor‐free composite coatings with high wear resistance and liquid puncture resistance is an interesting challenge. Herein, a new biomass benzoxazine monomer (C‐d) was synthesized, which was then sprayed on a glass slide, followed by spraying hyperbranched polysiloxane (HSi), polydopamine‐coated micro AlN (P@mAlN), and polydopamine‐coated nano AlN (P@nAlN), successively, to develop a new type of photothermal anti/deicing four‐layer fluor‐free composite coatings with high wear resistance and liquid puncture resistance (C‐d/yHSi/0.4P@2bAlN, y is the mass ratio of HSi to C‐d). Three‐layer composite coatings (C‐d/0.4P@zbAlN, z is the mass ratio of P@mAlN to P@nAlN) and two‐layer composite coatings (C‐d/xP@mAlN, x is the mass ratio of P@mAlN to C‐d) were also prepared to study the influence of compositions on comprehensive properties of coatings. The results show that C‐d/0.4P@zbAlN has significantly longer icing delay time (IDT) than C‐d and C‐d/xP@mAlN coatings but still shows poor wear resistance and liquid puncture resistance. Interestingly, C‐d/yHSi/0.4P@2bAlN coatings have good superhydrophobicity; as y increases, both IDT and wear resistance increase significantly. When y = 0.5, the obtained C‐d/0.5HSi/0.4P@2bAlN coating has the best integrated performance, including high anti‐deicing property (IDT = 627 s), high wear resistance, and liquid puncture resistance as well as good photothermal deicing performance, the ice melts in 343 s under the irradiation with 808 nm infrared light, overcoming the bottleneck of poor wear resistance and liquid puncture resistance of photothermal anti/deicing coatings. Besides, C‐d/0.5HSi/0.4P@2bAlN coating can effectively prevent the adhesion of pollutants and remain superhydrophobicity after soaked in different solutions (pH = 1–10). Highlights: A new biomass benzoxazine with good flexibility was synthesized.Photo‐thermal anti/deicing coatings with micro/nanostructured surfaces are built.The fluor‐free coatings have excellent wear resistance and chemical resistance.The mechanism behind was elucidated. [ABSTRACT FROM AUTHOR]

BACKGROUND: Medical titanium and titanium alloy have achieved good therapeutic effects in clinical applications, but there are still some phenomena such as peri-implant inflammation, loosening and shedding. OBJECTIVE: To explore the physicochemical properties of graphene oxide coating materials and their effects on bone marrow mesenchymal stem cells. METHODS: (1) Hydroxyapatite coating and graphene oxide/hydroxyapatite composite coating were prepared on a titanium surface by electrochemical deposition. The surface morphology, phase structure, functional groups, elemental composition and surface hydrophilicity of the coating were analyzed by scanning electron microscopy, X-ray energy dispersion spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, and contact angle measurement instrument. (2) Mouse bone marrow mesenchymal stem cells were isolated and cultured and inoculated on pure titanium, hydroxyapatite coating and graphene oxide/hydroxyapatite composite coating, respectively. CCK-8 assay and scanning electron microscopy were used to evaluate the proliferation, morphology and growth status of the coated cells. RESULTS AND CONCLUSION: (1) Scanning electron microscopy and X-ray energy dispersion spectra showed that the surface of graphene oxide/hydroxyapatite composite coating was more flat, compact and uniform than that of hydroxyapatite coating and pure titanium. X-ray photoelectron spectroscopy, X-ray diffraction and Raman spectroscopy showed that hydroxyapatite coating and graphene oxide/hydroxyapatite composite coating were successfully prepared on the surface of the titanium sheet. The hydrophilicity of graphene oxide/hydroxyapatite composite coating was better than that of hydroxyapatite coating and pure titanium. (2) CCK-8 assay showed that the number of bone marrow mesenchymal stem cells on the surface of the three groups increased with the extension of co-culture time. On days 1, 4, and 7, the proliferative absorbance of the cells on the graphene oxide/hydroxyapatite composite coating was higher than that on hydroxyapatite coating and pure titanium (P < 0.000 1). Scanning electron microscopy after 4 days of co-culture showed that bone marrow mesenchymal stem cells on the surface of the three groups of materials were fusiform. The cells on the surface of graphene oxide/hydroxyapatite composite coating showed good tensile properties and were polygonal. Multiple antennae could be seen attached to the coating surface at the edge of the cells, and the elongation of the filamentous foot on the surface was more than that on pure titanium and hydroxyapatite coatings. (3) The results show that graphene oxide/ hydroxyapatite composite coating material is a kind of coating material with excellent physicochemical and biological properties. [ABSTRACT FROM AUTHOR]

Flexible La-doped Sm2Zr2O7/polyurethane (PU) coated leather composites were synthesized using a one-step hydrothermal method, with highly efficient photocatalytic degradation properties by coating the La-doped Sm2Zr2O7/PU emulsion onto the leather and drying it. The phase composition and optical properties of the as-prepared photocatalytic material were systematically characterized. The result revealed that La was doped in Sm2Zr2O7 successfully, and the prepared samples still possessed pyrochlore structure. The absorption edge of the prepared samples exhibited a red-shift with the increase in La doping, indicating that La doping could broaden the absorbance range of the La-doped Sm2Zr2O7 materials. The catalytic performance of La-doped Sm2Zr2O7/PU composite emulsion coating on the photocatalytic performance of leather was studied with Congo red solution as the target pollutant. The results showed that the best photocatalytic property was found in the 5% La-doped Sm2Zr2O7 nanomaterial at a concentration of 3 g/L. The resulting 5% La-doped Sm2Zr2O7 nanomaterial exhibited a high specific surface area of 73.5 m2/g. After 40 min of irradiation by a 450 W xenon lamp, the degradation rate of Congo red reached 93%. Moreover, after surface coating, the La-doped Sm2Zr2O7/PU coated leather composites showed obviously improved mechanical properties, as the tensile strength of La-doped Sm2Zr2O7/PU coated leather composites increased from 6.3 to 8.4 MPa. The as-prepared La-doped Sm2Zr2O7/PU coated leather composites with enhanced mechanical properties and highly efficient photocatalytic performance hold promising applications in the treatment of indoor volatile organic compounds. [ABSTRACT FROM AUTHOR]

High-velocity oxy-fuel (HVOF) thermally sprayed Cr3C2-NiCr coatings have been shown to be effective in shielding important machinery and equipment components from wear in harsh, high-temperature conditions. In this investigation, the HVOF thermal spray coating technique was used to deposit Cr3C2-NiCr powder with 10% Co particles onto ductile cast iron. The effect of the Co particles on the mechanical, tribological, and microstructure characteristics of a Cr3C2-NiCr/ductile cast iron system was investigated. The microstructure analysis employed various techniques, including light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Scratch tests were applied to analyze the coating quality and adhesion. The coatings created using the HVOF spray method with Cr3C2-NiCr powders mixed with Co particles exhibited a dense structure containing large Co particles, partially melted, and very fine Cr3C2 particles embedded into the NiCr alloy matrix. Additionally, they possessed high hardness and excellent adhesion to the substrate. The results of bending strength tests were also presented, together with information on the coating's microhardness and fracture toughness. These included an analysis of the cracks and delamination in the Cr3C2-NiCr/ductile cast iron system. It was observed that the addition of Co particles significantly increased the resistance to cracking and wear behavior in the studied system. [ABSTRACT FROM AUTHOR]

In response to the rapid development of high-performance electronic devices, diamond/Al composites with high thermal conductivity (TC) have been considered as the latest generation of thermal management materials. This study involved the fabrication of diamond/Al composites reinforced with Ti-coated diamond particles using a liquid–solid separation (LSS) method. The interfacial characteristics of composites both without and with Ti coatings were evaluated using SEM, XRD, and EMPA. The results show that the LSS technology can fabricate diamond/Al composites without Al4C3, hence guaranteeing excellent mechanical and thermophysical properties. The higher TC of the diamond/Al composite with a Ti coating was attributed to the favorable metallurgical bonding interface compounds. Due to the non-wettability between diamond and Al, the TC of uncoated diamond particle-reinforced composites was only 149 W/m·K. The TC of Ti-coated composites increased by 85.9% to 277 W/m·K. A simultaneous comparison and analysis were performed on the features of composites reinforced by Ti and Cr coatings. The results suggest that the application of the Ti coating increases the bending strength of the composite, while the Cr coating enhances the TC of the composite. We calculate the theoretical TC of the diamond/Al composite by using the differential effective medium (DEM) and Maxwell prediction model and analyze the effect of Ti coating on the TC of the composite. [ABSTRACT FROM AUTHOR]

Titanium and its alloys are extensively applied in artificial tooth roots because of their excellent corrosion resistance, high specific strength, and low elastic modulus. However, because of their biological inertness, their surface needs to be modified to improve the osteointegration of titanium implants. The preparation of biologically active calcium–phosphorus coatings on the surface of an implant is one effective method for enhancing the likelihood of bone integration. In this study, osteoinductive peptides were extracted from oyster shells by using acetic acid. Two peptide-containing hydroxyapatite (HA) composite coatings were then prepared: one coating was prepared by hydrothermally synthesizing an HA coating in the presence of peptides (HA/P/M), and the other coating was prepared by hydrothermally synthesizing HA and then immersing the hydrothermally synthesized HA in a peptide solution (HA/P/S). Characterization results indicated that the composite HA coatings containing oyster shell-based peptides were successfully prepared on the alkali-treated pure titanium surfaces. The HA/P/M and HA/P/S composite coatings were found to exhibit excellent hydrophilicity. Protein adsorption tests confirmed that the HA/P/M and HA/P/S coatings had an approximately 2.3 times higher concentration of adsorbed proteins than the pure HA coating. [ABSTRACT FROM AUTHOR]

This study aims to produce by robocasting leucite/zirconia pieces with suitable mechanical and tribological performance, convenient aesthetics, and antibacterial properties to be used in dental crown replacement. Leucite pastes reinforced with 12.5%, 25%, and 37.5% wt. ZrO 2 nanoparticles were prepared and used to print samples that after sintering were characterized in terms of density, shrinkage, morphology, porosity, mechanical and tribological properties and translucency. A coating of silver diamine fluoride (SDF) and potassium iodide (KI) was applied over the most promising material. The material's antibacterial activity and cytotoxicity were assessed. It was found that the increase of ZrO 2 reinforcement up to 25% enhanced both microhardness and fracture toughness of the sintered composite. However, for a superior content of ZrO 2 , the increase of the porosity negatively affected the mechanical behaviour of the composite. Moreover, the composite with 25% ZrO 2 exhibited neglectable wear in chewing simulator tests and induced the lowest wear on the antagonist dental cusps. Although this composite exhibited lower translucency than human teeth, it was three times higher than the ZrO 2 glazed material. Coating this composite material with SDF+KI conferred antibacterial properties without inducing cytotoxicity. Robocasting of leucite reinforced with 25% ZrO 2 led to best results. The obtained material revealed superior optical properties and tribomechanical behaviour compared to glazed ZrO 2 (that is a common option in dental practice). Moreover, the application of SDF+KI coating impaired S. aureus proliferation, which anticipates its potential benefit for preventing pathogenic bacterial complications associated with prosthetic crown placement. [Display omitted] • Three pseudoplastic leucite/ ZrO 2 pastes were robocasted for dental applications. • 25% ZrO 2 samples showed the highest microhardness and fracture toughness. • When tested against dental cusps they suffered and induced the lowest wear. • They showed lower translucency than teeth, but significantly higher than glazed ZrO 2. • SDF+KI coating provided antibacterial properties, without inducing cytotoxicity. [ABSTRACT FROM AUTHOR]

In this work, manganese‐based metal‐organic frameworks (MnBDC) were synthesized by solvothermal method and physically mixed with pre‐prepared graphene oxide (GO) to obtain GO/MnBDC, which were calcined to give MnO@C composite coated with reduced graphene oxide (rGO) marked as rGO/MnO@C. The materials were characterized by SEM, XRD, FTIR and XPS. Based on this composite, a novel sensor was constructed on a glassy carbon substrate, which exhibited good electrocatalytic activities to the redox reactions of catechol (CC) and hydroquinone (HQ), enabling simultaneous detection of both analytes. Under optimized conditions, the electrochemical sensor demonstrated a linear range of 0.50–90.00 μM for both CC and HQ detection, with respective detection limits of 0.05 μM and 0.03 μM. Moreover, the sensor exhibited excellent sensitivity, selectivity and accuracy for detecting CC and HQ simultaneous in real samples. [ABSTRACT FROM AUTHOR]

Micro-arc oxidation (MAO) is widely applied to improve the corrosion resistance of Mg alloys by forming a ceramic passivation film on their surface. The high cohesive strength and randomly distributed micro-porous structure of MAO films have significantly expanded their operation scope, serving as the base or bonding layer for composite or multi-functional coatings. However, mechanical scratches or impacts during installation and service periods can damage the protective performance of MAO films, leading to local corrosion or the rapid loss of mechanical integrity in Mg alloys. Therefore, the development of MAO coatings with self-healing properties has been extensively studied in recent decades. This paper aims to illustrate the gaps between the anti-corrosion characteristics and self-repairing mechanisms dependent on the oxide composition or porous structure of MAO films. The progress in preparation and the principle of inhibitor loading in self-healing functional MAO-based composite coatings are summarized, and future directions are highlighted. [ABSTRACT FROM AUTHOR]

Al-CNTs composite coatings were successfully prepared on AZ31 alloy using laser cladding (LC). The effect of TiC nanoparticles on microstructure and corrosion resistance of the LC Al-CNTs and Al-TiC-CNTs composite coatings were investigated. The LC composite coatings were composed of α-Mg solid solution phase and β-Al12Mg17, Mg2Al3, Mg32(Al,Zn)49 and TiC compound phases. A sound metallurgical bonding interface was produced between the LC composite coatings and AZ31 alloy. The surface microhardness and corrosion resistance of the LC composite coatings, which were gradually decreased with increasing the content of carbon nanotubes (CNTs) and TiC nanoparticles, were significantly enhanced compared to those of the AZ31 alloy. The LC Al-CNTs (99 wt% Al + 1 wt% CNTs) composite coating exhibits excellent surface microhardness and corrosion resistance. The mean surface microhardness, self-corrosion potential and self-corrosion current were 266.4 HV, −1.233 V and 2.55 × 10−5 A, which were 426.2%, 78.9% and 16.5% of the AZ31 alloy, respectively. [ABSTRACT FROM AUTHOR]

In this paper, polyamine-functionalized carbon dots (CDs) were synthesized by means of low temperature (<100°C) carbonization of citric acid at the presence of polyethylenimine (PEI), resulting spherical calcium carbonate micro-particles from inverse micro-emulsion system. Nanoscaled spherical silicas were prepared by Stöber method via deposition on the surface of micron calcium carbonate. Scanning- and transmission-electron microscopic analysis confirmed a micro-/nano-complex structure, enabling the composite material coating possessed coarser surface similar to those of 'lotus leaf'. After modification with 1 H, 1 H, 2 H, 2 H-perfluorodecanethiol, both good super hydrophobicity and good fluorescent performance were confirmed by the water contact angle of 154.1°±1.5°, their surface-free energy, and fluorescence quantum yield of 14.1%, which provides an inexpensive and easy way to fabricate superhydrophobic material with fluorescence characteristics and promotes high value application of inorganic materials. [ABSTRACT FROM AUTHOR]

The properties and activity of TiO2-based nanorods as an antifouling agent and a photocatalyst for the catalytic degradation of methylene blue (MB) have been investigated. A modification of TiO2 with SiO2 was first carried out to enlarge the surface area. In order to enhance the TiO2 photo response to the visible light region, a further modification of TiO2-SiO2 (TS) composites with polyaniline (PANI) was also conducted. The nanorod TiO2 exhibited an anatase structure based on the diffraction patterns. The TEM images showed that some TiO2 molecules were attached around SiO2 with a random orientation. The TiO2-SiO2-PANI (TS-PANI) exhibited the largest specific surface area (SBET) of about 256.85 m²/g. The profile on the AFM images of the composites showed that the nano-roughness of the coatings was confirmed. The photocatalytic activity was evaluated through the degradation of MB both on the powder and the coated composites. The photocatalytic activity on the coatings was verified due to further application as anti-fouling coatings involving photocatalytic mechanism. The degradation of MB using TS-PANI powder and TS-PANI coating composites was 89.5% and 90.2%, respectively, with the irradiation time on the coatings was 20 min longer. The antifouling activity through the photocatalytic mechanism and nano-roughness surface was confirmed by the inhibition of barnacle growth on the teakwood surface immersed for two months in the sea. [ABSTRACT FROM AUTHOR]

A new type of energetic composite with a double-coating structure was constructed by in-situ polymerization of dopamine and water suspension method. Using CL-20 with a particle size of 200–500 nm as the main explosive, the core–shell structured CL-20-p (CL-20@PDA) was prepared via self-polymerization of dopamine on the surface of the CL-20. After that, thermoplastic polyurethane (TPU, Estane5703) was used as the binder, the CL-20-p was coated by water suspension method, and finally CL-20-p/Estane5703 composite was prepared. The structure and properties of the samples were characterized by SEM, AFM, FTIR, XPS, Raman, XRD, DSC and mechanical sensitivity test. The test results show that the CL-20-p is successfully coated by Estane5703, and the coating degree is high. Compared with the CL-20, the crystal phase transition temperature of CL-20/Estane5703 is significantly increased, and the mechanical sensitivity is greatly reduced. The CL-20-p/Estane5703 is superior to CL-20-p and CL-20/Estane5703 in enhanced thermal stability and reduced mechanical sensitivity. [ABSTRACT FROM AUTHOR]

Nanoscale yttria-stabilized zirconia (YSZ) and La 2 O 3 were used to prepare a composite coating by electrophoretic deposition (EPD) and sintering to improve the high-temperature oxidation resistance of AISI430 stainless steel. SEM, XRD, and TEM were used to identify the microstructure of the YSZ/La 2 O 3 composite coating and the oxide film formed at 900 °C. The effect of the EPD voltage on the coating thickness was studied. The microstructure properties and phase transition of the composite coatings during sintering were identified. The oxidation behavior of the composite coating at 900 °C was investigated by analyzing the oxidation kinetics curve, oxidation spallation, the formation of the interfacial oxide film, and the evolution of the coating microstructure. A model of the microstructure evolution of the YSZ/La 2 O 3 composite coating during EPD, sintering, and high-temperature oxidation was proposed and discussed. [ABSTRACT FROM AUTHOR]

In this study, a dual amorphous/crystalline nanocomposite coating of Ni–P/Ni–Mo–ZrO 2 was designed and successfully deposited on pure copper substrates by pulse electrodeposition. The design of the Ni–P/Ni–Mo–ZrO 2 dual coating takes advantage of the properties of the different structures and incorporates second phase reinforcing particles resulting in more comprehensive protective coatings. The surface morphology and microstructure were evaluated by SEM, EDS, WLI, XRD and TEM. The mechanical properties and electrochemical behaviors of the coating in a 3.5 wt% NaCl solution were investigated by wear tests, Tafel and EIS. The results show that the Ni–P/Ni–Mo and Ni–P/Ni–Mo–ZrO 2 dual coatings are uniform, dense and crack-free, and the duplex interface is homogeneous. Compared with the Ni–Mo coating, the average friction coefficient and wear rate of the Ni–P/Ni–Mo duplex coating decreased to 0.18 and 5.433 × 10−4 mm3/N·m, respectively. The corrosion potential is positively shifted to −0.43 with a maximum impedance of 308 kΩ cm2. The mismatch of the interlayer defects causes a deviation in the corrosion path, resulting in a transformation from longitudinal pinhole corrosion into extended transverse corrosion, which effectively strengthens the capacity of the coating for corrosion resistance while maintaining the high hardness of its outer coating. Furthermore, the hardness of the dual Ni–P/Ni–Mo coating can be obviously reinforced by nanoparticles from 730 HV to 810 HV, the corrosion potential is shifted to −0.41 V, and the corrosion current density decrease to 7.7803 × 10−7 A/cm2. The improvement in the mechanical properties can be attributed to the ZrO 2 nanoparticles, which could carry stress and transfer loads during the wear process. Meanwhile, the ZrO 2 nanoparticles can reduce the nodule size by filling the binding boundary which is the main corrosion path, and reduce the number of surface defects, such as pinholes, which leads to a lower corrosion rate. In addition, the corrosion inhibition and nanoparticle codeposition mechanisms of the duplex coatings were further discussed. [ABSTRACT FROM AUTHOR]

The 300 µm thick (Ti,Cr,V)N nanocomposite coatings were prepared by plasma spraying technique combined with combustion synthesis reaction of N and Ti-Cr-V reconstituted composite powders, and their microstructure and hardening mechanism were explored. The phases and microstructures were analysed by X-ray diffractometer, X-ray photoelectron spectroscopy and scanning electron microscopy, transmission electron microscopy, respectively, and a microhardness tester was employed to measure the microhardness. The main phase of the composite coating is (Ti,Cr,V)N solid solution, which has a multilayered structure of elongated columnar dendrites arranged in parallel, with different solidification positions resulting in crystal bundles possibly having different orientations. The composite coating has nanoscale fine crystals, as well as two typical strengthening models, "dislocation-TB" and "lattice distortion", which together contribute to the high hardness of the (Ti,Cr,V)N composite coating. The (Ti,Cr,V)N composite coating containing 10 wt% Cr has better surface morphology and the highest microhardness value (1844.80 HV 0.5). • Plasma spraying nano multi-nitride thick coatings in air. • The coating with multi-layer nanoclustered dendrites in various orientations. • Hardening mechanism: Besides Fine Crystal, "Dislocation-TB" and "Lattice Distortion". [ABSTRACT FROM AUTHOR]

Herein, biomass-based anti-corrosion composite fillers for water-based epoxy resin coatings, epoxy resin powder coatings, and efficient anticorrosive coatings were successfully prepared. Polyaniline/sugarcane bagasse composites (PANI–SCB) were prepared by in situ polymerization after the sugarcane bagasse was ground into a powder with a planetary ball mill. SEM results showed that a large number of loose polyaniline particles were formed on the surface of bagasse. Electrochemical testing showed that the water-based epoxy resin coating with 1% PANI–SCB had a low corrosion current density (5.466 × 10−7 A cm−2) and the highest low-frequency impedance modulus (34 260 Ω cm−2). The high protection efficiency (99.57%) and slow decline in impedance with a long soaking time indicated satisfactory anti-corrosion performance. On this basis, the prepared powder coating with 3% PANI–SCB presented a low corrosion current and high protection efficiency (99.39%). In addition, the powder coating had considerable adhesion fastness, flexibility, and commercially viable chemical resistance. XRD analysis found that the presence of Fe2O3 and Fe3O4 in the corrosion products can effectively induce the formation of a dense passivation film, thereby improving the corrosion resistance. The economic and environmental composite coating is expected to function in the anti-corrosion maintenance of hydropower station facilities. [ABSTRACT FROM AUTHOR]

Thermal conductive coating materials with combination of mechanical robustness, good adhesion and electrical insulation are in high demand in the electronics industry. However, very few progresses have been achieved in constructing a highly thermal conductive composites coating that can conformably coat on desired subjects for efficient thermal dissipation, due to their lack of materials design and structure control. Herein, we report a bioinspired thermal conductive coating material from cellulose nanofibers (CNFs), boron nitride (BN), and polydopamine (PDA) by mimicking the layered structure of nacre. Owing to the strong interfacial strength, mechanical robustness, and high thermal conductivity of CNFs, they do not only enhance the exfoliation and dispersion of BN nanoplates, but also bridge BN nanoplates to achieve superior thermal and mechanical performance. The resulting composites coating exhibits a high thermal conductivity of 13.8 W/(m·K) that surpasses most of the reported thermal conductive composites coating owing to the formation of an efficient thermal conductive pathway in the layered structure. Additionally, the coating material has good interface adhesion to conformably wrap around various substrates by scalable spray coating, combined with good mechanical robustness, sustainability, electrical insulation, low-cost, and easy processability, which makes our materials attractive for electronic packaging applications. [ABSTRACT FROM AUTHOR]

The paper reports on four cyclic tests of brick masonry spandrels in reference state and strengthened state. The tests were carried out on full-scale, H-shaped masonry panels to investigate the coupling role of the spandrel in connecting two piers in a historical masonry wall subjected to in-plane lateral actions. Two 250-mm-thick solid-brick masonry samples were tested—one single-leaf, the other two-leaves masonry. Both samples were tested before and after strengthening by applying a Composite Reinforced Mortar (CRM) coating on one surface. The CRM coating consisted of a lime mortar coating (nominal thickness = 30 mm), reinforced with mesh made of Glass Fibre-Reinforced Polymer (GFRP) that was anchored to the wall by GFRP transverse connectors. For the double-leaf masonry, there were additional transverse connectors made of steel bars in concrete cores (artificial diatones) to prevent masonry leaves separation and to improve the bonding of the CRM coating to the masonry. The test responses are compared in terms of crack pattern, failure mode, resistance, displacement and energy dissipation capacity. The tests showed the effectiveness of the proposed CRM system, which increased the spandrel resistance by 33% and 125% in the single—and double-leaf masonry, respectively, with the ultimate drift being 3.2% (one order of magnitude greater than for the unstrengthened reference samples). Data on energy dissipation and the equivalent viscous damping are also collected and compared. Importantly, the presence of the reinforcing mesh and the composite action of the coating and the wall changed the damage evolution and response mechanism, which resulted in a much better seismic response. [ABSTRACT FROM AUTHOR]

Ultra-high temperature ceramic (UHTC) has been developed to protect C/C composites exposed to high-temperature oxidizing environment. In this study, the effect of additive for the ablation behavior of ZrB 2 -based coating was investigated. The SiC–La 2 O 3 bond coat was firstly prepared on the C/C composites by the method of pack cementation (PC). ZrB 2 –SiC–Si (ZSS) and ZrB 2 –SiC–Al 2 O 3 (ZSA) coatings with dense microstructure and excellent interfacial bonding then were prepared on the surface of C/C composites coated with SiC–La 2 O 3 layer by the method of atmospheric plasma spraying (APS). The ablation experiments of all coated samples were conducted under oxyacetylene torch with a heat flux of 4.18 MW/m2. The microstructure, phase compositions, interfacial bonding, ablation and oxidation behaviors of coating were investigated. After ablation test, the ZrO 2 sketon with prorous structure was formed in the central region of ZSS coating. However, denser structure still can be observed at ZSA coating due to the formation of liquid phase. The SiC–La 2 O 3 –C/C interface are still without cracks. Furthermore, the diffusion of La element into ZSS and ZSA coatings from the SiC–La 2 O 3 layer was beneficial for the improvement of ablation resistance. The result indicated that SiC–La 2 O 3 /ZSA could effectively provide protection for C/C composites. [ABSTRACT FROM AUTHOR]

[Display omitted] Aluminum alloy (Al alloy) suffers from severe corrosion in acidic solution. Two-dimensional (2D) MXene-based composite coatings show great prospects for corrosion protection on metals used in special conditions. The composite coatings still face challenges in complex functionalization and orientation control. In harsh conditions, the long-term ability and roles of MXene in corrosion protection are still not clear. Here, a bio-inspired myristic-calcium chloride-Ti 3 C 2 T x MXene (MA + CaCl 2 + MXene) composite coating is successfully prepared on aluminum alloy (Al alloy) by electrodeposition process. Electrochemical tests, surface morphology, and chemical composition are analyzed to investigate the corrosion resistance and protection mechanism of the MXene coating in acidic solution (0.5 M H 2 SO 4 + 2 ppm HF). As a result, the incorporation of MXene can significantly reduce corrosion current density (7.498 × 10-8 A/cm2) by ∼ 5 orders of magnitude and impedance modulus at 0.01 Hz (|Z| 0.01 Hz) value of the composite coating is 196.8 Ω·cm2, which is over 4 times higher than that of bare Al alloy (40.74 Ω·cm2) after immersion test for 72 h. Furthermore, the in-situ corrosion test confirms the enhanced corrosion resistance of the MA + CaCl 2 + MXene composite coating. The MXene can increase coating thickness to 23.6 ± 0.4 μm, reduce porosity to (5.845 ± 1) × 10-5, decrease the diffusion coefficients of H+ to (1.587 ± 0.3) × 10-9 cm2/s, and enhance the adhesion of the coating to the substrate (the delamination time exceeds 5 h), thus providing improved anti-corrosion ability. This strategy opens up new prospects for construction of 2D MXene-based anti-corrosion coatings. [ABSTRACT FROM AUTHOR]

A novel Ni–SiO2 composite deposition layer was created in the inner wall of the pipe adopting a new type of brush plating device, and the properties of the deposition layer were characterized; experimental results show that the nanocomposite deposition layer significantly improves the mechanical properties and corrosion resistance of the inner wall of the pipe. Firstly, under the conditions of nanoparticle addition (40 mL/L, 60 mL/L, 80 mL/L), working voltage (12 V, 14 V, 16 V) and pH (5, 7, 9), the hardness value and surface morphology of deposited layer were investigated through orthogonal experiments, and the optimal process variables were preliminarily determined. Orthogonal experiment results show that when the addition of nanoparticles is 80 mL/L, the voltage is 14 V, and the pH value is 7, the Ni–SiO2 nanocomposite deposition layer has high microhardness (618.6 HV) and good microscopic morphology. According to the analysis of the results of the orthogonal experiment, the addition amounts of nanoparticles is the main influencing factor, so the control variable method is utilized to investigate the effect of the addition amounts of nanoparticles on the properties of the deposited layer. The results show that when the amounts of nanoparticles added is 80 mL/L, the surface of deposited layer is smoother, denser and less defective. Moreover, the deposited layer has excellent mechanical property and corrosion resistance. In a solution of 3.5% sodium chloride, −0.78 V is the corrosion potential, 1.93 × 10−5 A·cm−2 is the corrosion current density, and 0.22 mm·a−1 is the corrosion rate. [ABSTRACT FROM AUTHOR]

This study investigates a successful fabrication of MoS2/Fe3O4/PANI composite by chemical co‐precipitation method. The facile hydrothermal approach was employed to synthesize a MoS2/Fe3O4 composite, followed by the utilization of a conventional chemical oxidation strategy to produce a PANI coating on the composite, thereby generating an active material for electrochemical reactions and a structure facilitating the transportation of ions via multiple pathways. The fabricated MoS2/Fe3O4/PANI composite was characterized by SEM, ICP, XRD, FT‐IR, and so on. In this study, we delved into the electrochemical charge storage feature of MoS2/Fe3O4/PANI. The electrochemical characteristics of the nanocomposite were assessed through the implementation of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry techniques in a 3 M KOH electrolytic solution, utilizing nickel foam as both a material support and current collector for two electrode configurations. The findings indicate that MoS2, as the support matrix, possesses notable attributes such as a substantial surface area, elevated electrical conductivity, and varied oxidation states. As a result, the electrical conductivity performance of the MoS2/Fe3O4/PANI composite, which includes well‐dispersed Fe3O4 nano‐cubes on the surfaces of MoS2, is significantly enhanced. In comparison to pure Fe3O4, the resultant composite revealed improved specific capacitances of 401 F/g at 1.25 A g−1, along with outstanding cyclic stability of 89.3 even after undergoing 5000 cycles. The superior electrochemical properties observed may be ascribed to both the proficient electrical conductivity of MoS2 and the incorporation of Fe3O4 particles, which are anchored onto the MoS2. The results prove that MoS2/Fe3O4/PANI hybrid composite holds as highly efficient electrode material for supercapacitor. [ABSTRACT FROM AUTHOR]

The instability of UV anti-corrosion coatings poses a significant threat to both air quality and the environment, highlighting the urgent need for efficient and eco-friendly anti-corrosion coatings. In this study, we synthesized a novel material, MXene, known for its well-defined layered structure and exceptional conductivity, by employing a MAX phase etching process. Our investigation encompassed the assessment of MXene's compatibility within UV coating systems, as well as its dispersion and stability within composite coating systems. We observed that MXene's substantial specific surface area and robust chemical adsorption capabilities played pivotal roles in the adsorption and stabilization of nanoparticles within the UV coating. Further exploration of MXene-based UV-curable anti-corrosion coatings revealed remarkable resistance to hydrogen-induced corrosion due to MXene's outstanding electrical conductivity and its ability to regulate surface chemical reactions. This optimization not only enhances UV-curing and photostability performance in UV anti-corrosion coatings but also makes them highly suitable for producing efficient anti-corrosion coatings. This approach demonstrates broad applicability across various substrates where superior corrosion resistance is essential. [ABSTRACT FROM AUTHOR]

Kinnow mandarin fruit possesses high nutraceutical value, but it exhibits heavy loss in antioxidant quality during long-term storage. The effect of sodium alginate coating and combination of Sodium Alginate (SA) and Neem Leaf Extract (NLE) coatings was evaluated on cold stored Kinnow fruits. The results revealed that fruits applied with composite coating exhibited slower decline in the levels of phenols (7.89%), flavonoids (16.8%) and carotenoid content (6.64%) during the storage as compared to the control. Coated fruits also retained better antioxidant activity as compared to the control during storage period. In addition, SA +NLE coating reduced the spoilage, loss in weight, loss of juice content, acidity and vitamin C in the Kinnow fruits. Similarly, at the end of 75 days storage period, maximum TA, TSS, juice content, Ascorbic acid, carotenoid content, TPC, TFC and anti-oxidant activity was maintained in 2% SA + 20% NLE coating, hence being the most effective coating. [ABSTRACT FROM AUTHOR]

Organic coatings containing solid lubricants effectively prevent contact between recycled aluminum alloy surfaces and molds, thereby preventing damage caused by impurities. PVB-based easily removable coatings show promise in the stamping industry, but there is scarce research on the interactions of various lubricating additives within easily removable binder systems and their lubrication effects. This paper primarily concentrates on the synthesis of PVB-based composite coatings containing PTFE and MoS2. It delves into the synergistic lubrication mechanism of MoS2 and PTFE on mold steel, as investigated through cupping and tribological tests. The results show that the compounded coating exhibits superior dispersion, lubrication performance, tribological properties, and can withstand higher stamping loads compared to single-component coatings. MoS2 demonstrates exceptional extreme pressure performance and enhances the transfer capability of the coating. PTFE reduces the friction coefficient while minimizing coating adhesion to the die surface. This study provides a theoretical foundation for selecting solid lubricants in organic thin coatings for stamping lubrication. [ABSTRACT FROM AUTHOR]

Corrosion-related damage incurs significant capital costs in many industries. In this study, an anti-corrosive pigment was synthesized by modifying calcium carbonate with sodium alginate (SA), and smart self-healing coatings were synthesized by reinforcing the anti-corrosive pigments into a polyolefin matrix. Structural changes during the synthesis of the anti-corrosive pigment were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Moreover, thermal gravimetric analysis confirmed the loading of the corrosion inhibitor, and electrochemical impedance spectroscopic analysis revealed a stable impedance value, confirming the improved corrosion resistance of the modified polyolefin coatings. The incorporation of the anticorrosive pigment into a polyolefin matrix resulted in improved pore resistance properties and capacitive behavior, indicating a good barrier property of the modified coatings. The formation of a protective film on the steel substrate reflected the adsorption of the corrosion inhibitor (SA) on the steel substrate, which further contributed to enhancing the corrosion resistance of the modified coatings. Moreover, the formation of the protective film was also analyzed by profilometry and elemental mapping analysis. [ABSTRACT FROM AUTHOR]

To enhance the comprehensive performance of solid oxide fuel cells (SOFCs) ferritic stainless steel (FSS) interconnectors, a novel approach involving composite electrodeposition and thermal conversion is proposed to prepare Ni-doped Co-Mn composite spinel protective coatings on FSS surfaces. The process involves the composite electrodeposition of a Ni-doped Co-Mn precursor coating, followed by thermal conversion to obtain the Co-Mn-Ni composite spinel coating. Crofer 22H was used as the substrate and orthogonal experiments were designed to investigate the influences of deposition solution pH, stirring rate, cathode current density, and the element content of Mn and Ni on the surface morphology and properties of the composite coatings, respectively. The characterization of the prepared coatings was conducted through macroscopic and microscopic morphology observations of the component surface, energy dispersive spectroscopy (EDS) analysis, and area specific resistance (ASR) testing, etc. Finally, the optimized composite electrodeposition parameters and the Mn-Ni content ratio in the solution were obtained. Experimental results indicated that the composite spinel coating prepared with the optimized process parameters exhibited excellent adhesion to the substrate, and the diffusion and migration of Cr element has been effectively inhibited. Compared with the substrate, the ASR of the coated components has also been decreased simultaneously, which provided an effective method for the surface modification of SOFC FSS interconnectors. [ABSTRACT FROM AUTHOR]

The hardness and wear resistance of the surface of TC4 titanium alloy, which is widely used in aerospace and other fields, need to be improved urgently. Considering the economy, environmental friendliness, and high efficiency, Si-reinforced Ti-based composite coatings were deposited on the TC4 surface by the high-speed wire-powder laser cladding method, which combines the paraxial feeding of TC4 wires with the coaxial feeding of Si powders. The microstructures and wear resistance of the coatings were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Vickers hardness tester, and friction and wear tester. The results indicate that the primary composition of the coating consisted of α-Ti and Ti5Si3. The microstructure of the coating underwent a notable transformation process from dendritic to petal, bar, and block shapes as the powder feeding speed increased. The hardness of the composite coatings increased with the increasing Si powder feeding rate, and the average hardness of the composite coating was 909HV0.2 when the feeding rate reached 13.53 g/min. The enhancement of the microhardness of the coatings can be attributed primarily to the reinforcing effect of the second phase generated by Ti5Si3 in various forms within the coatings. As the powder feeding speed increased, the wear resistance initially improved before deteriorating. The optimal wear resistance of the coating was achieved at a powder feeding rate of 6.88 g/min (wear loss of 2.55 mg and friction coefficient of 0.12). The main wear mechanism for coatings was abrasive wear. [ABSTRACT FROM AUTHOR]

Magnesium hydride (MgH2) has been recognized as a promising anode material of lithium‐ion batteries (LIBs) owing to its ultrahigh specific capacity. The low conductivity and the structural pulverization induced by large volume expansion, however, has long limited its practical lithium storage performance. Herein, a series of yolk‐shell‐like structures, composed of porous MgH2 nanoparticles (NPs) decorated with Mg‐based composites through in‐situ solid‐gas reaction using MgH2 as both the reactant and the structural template, have been fabricated and uniformly dispersed on electronically conductive graphene. It could not only physically accommodate the volume change of MgH2 owing to the physical protection of Mg‐based composites and the formation of void space inside MgH2 NPs, but also effectively facilitate the transportation of electrons throughout the whole electrode. Particularly, the uniform decoration of ultrathin Mg(BH4)2 as the shell with thermodynamically favorable intercalation of lithium ions and low kinetic barrier for the lithium‐ion diffusion promotes facile transportation of lithium ions into active MgH2, which, coupled with the porous structure constructed by flexible graphene, effectively improves the ion conductivity of the electrode. The synergistic improvement in electronic and ionic conductivity leads to a high reversible capacity of 1651 mAh g−1 at 200 mA g−1 after 380 cycles. [ABSTRACT FROM AUTHOR]

In order to solve the problem of poor tribocorrosion resistance of Q235, FeCrMoCBSi Fe-based amorphous composite coatings were fabricated on the surface of Q235 by laser cladding. The microstructure, mechanical properties and tribocorrosion properties of the coating prepared by different laser powers were investigated. The loss behavior of coating and Q235 under the interaction of friction and corrosion was analyzed. It is shown that the coating prepared at 1000 W laser power has relatively high amorphous content and more refined microstructure, so that the microhardness of the coating is 1313HV0.2, and the loss components of tribocorrosion are less than one order of magnitude of Q235. With the increase of laser power, the amorphous content decreases, making the corrosion and wear resistance worse, and the wear mechanism changes from abrasive wear to adhesive wear, but it is still superior to Q235. In the tribocorrosion experiment, the material loss of tribocorrosion is more serious than that of friction or corrosion. In addition, the different material loss behaviors of the coating and Q235 are revealed, with the loss of the coating dominated by corrosion-induced wear and the material loss of Q235 dominated by friction. [ABSTRACT FROM AUTHOR]

The synergistic regulation of the cladding process and lubricating powder ratio is essential to enhance the quality of self-lubricating coatings. To systematically study the critical parameters for the preparation of Ni-based graphite self-lubricating composite coatings, the regression models between laser energy density, lubricating powder ratio, and overlap rate with shear strength and coefficient of friction were established by the BBD experimental model, and the effects of each parameter on the response were analyzed. Then, the optimal cladding parameters were solved with the EWM-AMPSO algorithm, and the reliability of the algorithm is proved by comparative verification method. Finally, the properties of the optimal coating were analyzed. The reason for the improved wear resistance and interfacial bonding properties of the coating was obtained to be the formation of enhanced phases, homogeneous microstructure and graphite, the lubricating film formed by wear, and good fracture toughness. [ABSTRACT FROM AUTHOR]

Blood-contacting medical devices, such as vascular stents, intravascular catheters, and artificial heart valves, frequently encounter complications in clinical practice, including thrombosis, inflammatory reactions, and infections. These challenges pose significant obstacles in the effective application of blood-contacting medical devices. Given that protein adhesion serves as the primary trigger for detrimental events upon contact with blood, this review focuses on various anti-fouling coating strategies aimed at inhibiting protein adsorption. Currently, surface modification of blood-contacting medical devices primarily involves the construction of active or passive anti-fouling coatings. This review explores the implementation of active and passive anti-fouling coating strategies utilizing chemistry, physics, and biotechnology. Examples of anti-fouling coatings discussed include hydrophilic polymer coatings, zwitterionic polymer coatings, superhydrophobic coatings, and composite coatings. Furthermore, we propose implementation approaches for these coatings to address inflammation and infection challenges associated with blood-contacting devices. The review concludes with a brief overview of current surface modification technologies employed in commercial anti-fouling coatings and offers insights into the future of anti-fouling coating technologies for blood-contacting material surfaces. These advancements are essential for the advancement of design, development, and application of blood-contacting materials. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to examine the impact of MoS2 on the microstructure and characteristics of micro-arc oxidized (MAO) ceramic coatings created on ZK60 magnesium alloy through the addition of varying concentrations of MoS2 particles to the electrolyte, aiming to enhance the corrosion resistance of magnesium alloy. Design/methodology/approach: The surface morphology, roughness and phase composition of the coatings were analyzed using scanning electron microscopy, a hand-held roughness tester and an X-ray diffractometer, respectively, and the corrosion resistance of the MAO coatings prepared by the addition of different contents of MoS2 particles was tested and analyzed using an electrochemical workstation. Findings: The results demonstrate that MoS2/MgO composite coatings have been successfully prepared on the surface of magnesium alloys through micro-arc oxidation. Furthermore, the corrosion resistance of the ZK60 magnesium alloy prepared with the addition of 1.0 g/L MoS2 was the best compared to the other samples. Originality/value: MoS2 particles were able to penetrate the coatings successfully during the micro-arc oxidation process, acting as a barrier in the micropores to prevent the corrosion medium from touching the surface, thus improving the corrosion resistance of the sample. The electrochemical workstation was used to study the corrosion resistance of the MoS2/MAO coating on the ZK60 magnesium alloy. [ABSTRACT FROM AUTHOR]

Hydrogen isotope permeation in structural steels can cause severe issues, including steel brittleness, fuel loss, and radioactive pollution in fusion reactors. To tackle this issue, we report a simple synthesis of α‐Al2O3/AlPO4 composite coating by the thermochemical reaction method to serve as an effective barrier hampering hydrogen isotope permeation. This coating was formed at 500°C and composed of α‐Al2O3 and AlPO4 phases. A relatively uniform and compact structure with thickness of ∼35 μm made its corrosion resistance reaching above 3000 times that of the 321 steel substrate. With just one‐side coated, the α‐Al2O3/AlPO4 coating achieved a considerable deuterium permeation reduction factor of 1935 at 450°C, three orders of magnitude higher than 321 steels. What's more, after the deuterium permeation test, no pores or cracks were generated. The excellent bonding between the coating and the substrate was resulted from the formation of CrxPy at their interface induced by Cr diffusion from the substrate. The results obtained from the current study shed new light on seeking reliable and viable ceramic coatings to tackle hydrogen permeation issues. [ABSTRACT FROM AUTHOR]

A novel gradient CrSi 2 -ZrSi 2 -SiC-Si coating for carbon/carbon (C/C) composites was prepared by optimized pre-oxidation and two-step pack cementation (PC) process. The microstructure and oxidation behavior of the coating were investigated in comparison to SiC-Si coatings. The results showed that the composite coating is mainly composed of CrSi 2 , ZrSi 2 , SiC and Si phases with a certain composition gradient, but no sharp interface. The coated specimens had a 4.83 mg/cm2 weight gain at 1773 K oxidation for 604 h, providing better oxidation resistance than the SiC-Si coated specimens (9.3 mg/cm2, 225 h). Its excellent performance was mainly attributed to the formation of glass and crystalline phases such as SiO 2 , ZrO 2 , Cr 2 O 3 and ZrSiO 4 , which provided better oxygen barrier ability and structural stability than the single SiO 2 glass. In addition, the maximum weight gain and steady-state linear weight loss rate of the coating during the oxidation process were related to long-term anti-oxidation performance. [ABSTRACT FROM AUTHOR]