Strong Abrasion Resistance Research Articles

Waterborne robust superhydrophobic PFDTES@TiO2-PU coating with stable corrosion resistance, long-term environmental adaptability, and delayed icing functions on Al–Li alloy

Aluminum–Lithium (Al–Li) alloys widely used in aerospace manufacture are highly susceptible to corrosion, which limits their industrial applications. Herein, 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) is used as a modifier for low-surface-energy treatment of TiO2 nanoparticles. The water-based polyurethane (PU) is made as a binder to achieve a tight bonding between modified ceramic particles and Al–Li alloy, thus resulting in the extremely-feasible air-spraying preparation of a superhydrophobic coating with strong abrasion resistance. The water contact angle (CA) of as-prepared coating achieves 160 ± 0.83°, and the rolling angle (SA) is as low as 5.95 ± 0.59°. The surface structure, organization and composition are further characterized using SEM, EDS, XPS and laser confocal microscopy. Meanwhile, the electrochemical impedance and potentiodynamic polarization tests are performed for corrosion characterization. The results show that the corrosion potential of such coating increases by 170 mV compared with substrate, the corrosion current density decreases by two orders of magnitude, and the impedance modulus increases by two orders. The corrosion inhibition rate of the as-prepared coating is 98.8%, indicating that the corrosion resistance has been significantly enhanced. In addition, the mechanical robustness and stability of the coating is evaluated and confirmed using a sandpaper rubbing test. It also possesses great self-cleaning, anti-pollution and thermostable behaviors, thereby allowing them to work in extreme manufactures. Moreover, the as-prepared coating exhibits excellent adaptability to various materials and anti-icing property. This work sheds positive insights in enlarging industrial applications of multifunctional ceramic coatings in aerospace fields.

Effect of UV Top Coating Microcapsules on the Coating Properties of Fiberboard Surfaces.

The commonly used ultraviolet ray (UV) curing coatings have the characteristics of fast curing speed, high hardness, strong abrasion resistance, etc. However, the self-healing properties of UV coatings after being damaged still need to be improved. Self-healing microcapsules can alleviate this problem. The UV top coating itself has good properties, so it can be directly chosen as the core material of microcapsules. UV top coating microcapsules can be added to the UV top coating to increase the self-healing properties of the UV coating to achieve the purpose of better protection of the UV coating and fiberboards. UV top coating microcapsules were prepared and added in different contents to characterize the effect on the physical, chemical, and self-healing properties of the UV coating on a fiberboard surface. The 1#, 2#, and 3# UV top coating microcapsules that were prepared with emulsifier HLB values of 10.04, 10.88, and 11.72, respectively, were added to the UV top coating at contents of 2.0%, 4.0%, 6.0%, 8.0%, and 10.0%. The UV coatings were applied to the fiberboard using a method of two primers and two top coatings, in which no microcapsule was added in the primer, and were tested and analyzed. The results showed that when the content of microcapsules was greater than 6.0%, close to 8.0%, the excessive density of microcapsules produced stacking and extrusion between the microcapsules. As a result, the core material could not flow out smoothly when part of the microcapsule was ruptured. The outflow of the core material was not efficiently utilized, thus leading to a decrease in the self-healing rate. The 2# UV top coating microcapsules of 4.0% made the UV coatings reach the self-healing rate of 26.41%. The self-healing rate of the UV coatings prepared with the 3# UV top coating microcapsules with 6.0% was up to 26.58%. The UV coatings prepared with the 1# UV top coating microcapsules of 6.0% had the highest self-healing rate among the three groups, up to 27.32%. The UV coatings of this group had the best comprehensive properties with a chromatic aberration ΔE of 4.08, a gloss of 1.10 GU, a reflectance of 17.13%, an adhesion grade of 3, a hardness of 3H, a grade 3 of impact resistance, and a roughness of 1.677 μm. An investigation of the UV coatings on fiberboard surfaces with the content of UV top coating microcapsules can provide support for the optimization of the self-healing properties of UV coatings and can also provide innovative ideas for the preparation of the self-healing coatings on fiberboard surfaces.

Microstructure and properties of laser-melted FeCoCrNiSiMox high-entropy alloy coatings

In this research, FeCoCrNiSiMox high-entropy alloy coatings were created using laser cladding technology on 45 steel surfaces in order to provide a coating with high hardness and strong abrasion resistance. The present study aims to evaluate the effects of including Mo elements on the tissue, structure, and mechanical characteristics of FeCoCrNiSiMox high mercury alloy coatings under optimal laser melting process conditions. Through the regulation of Mo element incorporation, it has been observed that for values of x less than or equal to 0.2, the coating exhibits a singular FCC structure. However, for values of x greater than 0.2, a phase transition occurs in the coating’s structure, resulting in the appearance of a second phase. Consequently, the alloy primarily comprises a solid solution phase combined with the FCC phase and the Mo-rich phase. The introduction of the Mo element results in a steady reduction in the microstructure of the coating, which predominantly consists of dendritic structures. Additionally, the average hardness of the coating exhibits an increase, accompanied by an enhancement in its wear resistance.

Ceramic Coating for High Temperature Corrosion Protection of Steel

Abstract: In high temperature environments where oxidation occurs which effects the metal in multiple ways. High temperature corrosion is typically seen in ductile steel. This can cause abrupt failure and reduce a metal's mechanical properties. A variety of ceramic coatings are available that can be applied to enhance functionality and prevent corrosion, particularly at high temperatures. The majority of ceramic coatings are typically electrically nonconducting, making them excellent insulators. It also has a high melting temperature of up to 4000⸰F and remarkable abrasion resistance. Due to these characteristics, they offer exceptional corrosion resistance and strong abrasion resistance in high temperature conditions. In this research, the team synthesize ceramic coating which may provide exceptional abrasion resistant as well high temperature oxidation resistance. Before selecting the ingredients, it needs to be examined the compatibility between mild steel (sample) and constituents of ceramic coating, majorly the thermal expansion characteristics. It must be identical otherwise fractures can be produced on the coated surface of a metal. Samples were made as per demand, following collecting a sample and cleaned accurately to attach the coating appropriately. After application of coating on sample it should place in furnace which promote diffusion on a metal surface and construct protective barrier. Further, dipping the sample in 3.5% NaCl solution for 21 days and execute the OCP and EIS test of naked sample and coated sample correspondingly for 5 days. Potentiostat provides several graphs viz OCP, Bode plot, Nyquist impedance plot and Tafel Extrapolation. High temperature oxidation resistance of the ceramic covering was investigated using TGA analysis. The weight gain of coated sample is roughly 1mg/cm2 compared to about 4 mg/cm2 for plain sample in TGA curve. This illustrates that the ceramic coating is averting oxidation of steel surface at high temperature of 500ºC.

Strong mechanical and durable superhydrophobic photothermal MWCNTs/SiO2/PDMS/PVDF composite coating for anti-icing and de-icing

A MWCNTs/SiO2/PDMS/PVDF superhydrophobic photothermal composite coating has been prepared by a simple scraping method. The coating can be scraped on different substrates and exhibit excellent superhydrophobic photothermal performance. The obtained superhydrophobic photothermal coating not only has excellent light absorption, acid and alkali resistance, weather resistance and simple preparation process, etc., but also has strong abrasion resistance, adhesion ability and weak light ice-melting performance. The coating still can keep a good superhydrophobic performance after about 80 and 30 abrasion cycles (~40 and 15 m) with about 3.3 and 8.2 kPa pressure on a 360-mesh sandpaper, respectively. Based on the method of Paints and Varnishes-Cross-Cut Test, the adhesion level of the coating can be classified as grade 1. Under 11.5 °C ambient temperature, the coating surface can reach a saturation temperature of around 30 °C with only 0.2 sun irradiation within 5 min. At −15 °C and no light irradiation, compared with the bare aluminum substrates, the coating can delay the freezing time more than twice. At −15 °C, the 0.2 sun irradiation intensity is enough for the coating to prevent 100 μL water droplets from freezing. In contrast, without the coating, the 100 μL water droplet started to freeze after 93 s with 0.2 sun irradiation and it was completely frozen after 285 s. Besides, the ice pellet began to melt after 271 s through the photothermal effect of the coating with low irradiation intensity of 0.2 sun at −15 °C. However, for the same ice pellet, the ice melting cannot occur without photothermal coating under the same conditions. The superhydrophobic photothermal coating shows good application potential in practical engineering.

Creating superhydrophobic, abrasion-resistant and breathable coatings from water-borne polydimethylsiloxane-polyurethane Co-polymer and fumed silica

HypothesisThe high surface area and branched structure of fumed silica (FS) can be exploited in concert with the hydrophobic properties of polydimethylsiloxane (PDMS) and robustness of polyurethane (PU) to create PDMS-PU and FS grafted coatings with hierarchical structures and enhanced functionalities. The structural features of FS would add to superhydrophobicity; its open-branchlike characteristics would provide air permeability; the use of a tiered coating approach involving a FS-only layer on top of the PDMS-PU coat would create interlocking and strong abrasion-resistance, leading to a multifunctional coating with potential application in filtration and personal protection equipment (PPE). ExperimentsPDMS-PU and PDMS-PU-Si copolymer dispersions are synthesized with different monomer molecular weights and FS concentration. Hydrophobicity is measured via water contact angle and wetting resistance measurements. Abrasion resistance is compared by investigating the fiber morphology and hydrophobicity of the coated fabrics after various abrasion cycles. Air flow versus pressure drop experiments are used to measure breathability. Interaction mechanism between substrate/components are explored using infrared spectroscopy. FindingsThe interactions between the substrate, FS, and PDMS-PU can be manipulated to create a novel, tiered coating that exhibits superhydrophobicity, strong abrasion resistance together with desirable air-permeability, thereby providing a versatile and unique coating platform.

Facile fabrication of durable superamphiphobic PET fabrics

Superamphiphobic coatings/materials are important for a wide variety of applications, but the majority of these coatings/materials still suffer from poor durability. Therefore, multifunctional superamphiphobic coatings/materials with strong mechanical and chemical stability are highly desired. Herein, a simple and flexible approach to produce multifunctional superamphiphobic poly(ethylene terephthalate) (PET) textiles was reported. First, dual micro/nanostructures on the PET fabric surface are constructed by hydrolysis of trimethoxymethylsilane, N-octyltriethoxysilane, and trimethylchlorosilane, and further modified by 1H,1H,2H,2H-perfluorodecyltriethoxysilane and poly(vinylidene fluoride). The as-obtained superamphiphobic PET fabrics show high liquid repellency to water, oil, organic liquids, and strong acid or alkali solutions, exhibiting a water contact angle (WCA) of 161° and an oil contact angle (OCA) of 156°. Meanwhile, the superamphiphobic PET fabrics show strong abrasion resistance; even after 180-cm consistent abrasion, the WCA still maintains 148° and the OCA maintains 140°. Importantly, the fabrics maintain their excellent superamphiphobic property after long-term UV irradiation or ultrasonic treatment, respectively. Because the prepared fabrics have multifunctional features and are easy to fabricate with low cost, they show great potential for self-cleaning, antifouling, anti-icing, drug reduction, corrosion resistance, and protective uniforms.

Evaluation of the cooling effect and anti-rutting performance of thermally resistant and heat-reflective pavement

ABSTRACTTo reduce asphalt pavement temperature and improve its anti-rutting performance in summer, thermally resistant friction course (referred to as TRFC-13), heat-reflective coating (referred to as HRC) and thermally resistant and heat-reflective coating integrated pavement (referred to as TR-HRC) were developed, and their cooling effect, anti-rutting performance and durability were evaluated. In addition, machine-made sands were applied to improve the anti-skid performance of the coating. The results show that compared with ordinary SMA-13 samples, the surface temperature of the TRFC-13, HRC and TR-HRC samples decreased by approximately 6.8°C, 11.2°C and 13.2°C, respectively. At the air temperature of approximately 40°C, the field road surface temperature of the TRFC-13, HRC and TR-HRC decreased by approximately 7.4°C, 12.2°C and 14.0°C, respectively. The higher the air temperature is, the better the anti-rutting performances of these three kinds of pavement. At the air temperature of 39°C, the dynamic stability of the TRFC-13, HRC and TR-HRC is 1.56 times, 1.86 times and 1.88 times that of the ordinary SMA-13, respectively. The results also show that HRC has a strong abrasion resistance and that spreading 40 wt% of machine-made sands can ensure the coatings achieve the best British Pendulum Number, without influencing its cooling performance.

Development of highly active coated monolith SCR catalyst with strong abrasion resistance for low-temperature application

Monolith SCR catalysts coated with V2O5-WO3/TiO2 were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V2O5-WO3/TiO2 powder, a coated monolith with a catalyst-coating layer of 260 µm in thickness exhibited the similar initial NOx reduction activity at 250°C. After 4 h abrasion (attrition) in an air stream containing 300 g·m–3 fine sands (50–100 µm) at a superficial gas velocity of 10 m·s–1, the catalyst still has the activity as a 100% molded monolith does in a 24-h activity test and it retains about 92% of its initial activity at 250°C. Estimation of the equivalent durable hours at a fly ash concentration of 1.0 g·m–3 in flue gas and a gas velocity of 5 m·s–1 demonstrated that this coated monolith catalyst is capable of resisting abrasion for 13 months without losing more than 8% of its initial activity. The result suggests the great potential of the coated monolith for application to de-NOx of flue gases with low fly ash concentrations from, such as glass and ceramics manufacturing processes.

Sliding Contact Between a Cylindrical Punch and a Graded Half-Plane With an Arbitrary Gradient Direction

Contact behavior of a rigid cylindrical punch sliding on an elastically graded half-plane with shear modulus gradient variation in an arbitrary direction is investigated. The governing partial differential equations and the boundary conditions are achieved with the help of Fourier integral transformation. As a result, the present problem is reduced to a singular integral equation of the second kind, which can be solved numerically. Furthermore, the presently general model can be well degraded to special cases of a lateral gradient half-plane and a homogeneous one. Normal stress in the contact region is predicted with different material parameters, which is usually used to estimate the possibility of surface crack initiation. The moment that is needed to ensure stable sliding of the cylindrical punch on the contact surface is further predicted. The result in the present paper should be helpful for the design of novel graded materials with surfaces of strong abrasion resistance.

Experimental Study on HMPE Fiber Reinforced Concrete

Abstract. Concrete as a most popular construction material has many advantages such as easiness to be formed into various shapes, common availability and relative low cost. However, the low tensile strength and brittleness are disadvantages for wider application of the material. In this study, an advanced material of high strength and strong abrasion resistance HMPE fiber was used to reinforce concrete properties. A series of experimental testing were carried out to examine the properties of both fresh and hardened HMPE fiber reinforced concrete. It was found that the addition of an HMPE fiber material in concrete may enhance its compressive strength as high as 20% increment without water-reducing admixture. If a water-reducing admixture was applied, the increment of compressive strength may reach as high as 25% for 1.5% volume ratio of fiber contained in concrete.

Cooling Principle Analyses and Performance Evaluation of Heat-Reflective Coating for Asphalt Pavement

In the experiment, a heat-reflective coating (HRC) was applied to the surface of asphalt pavement. The coating temperature reduction principle and the mechanism to mitigate the urban heat island effect (UHI) were explored by analyzing the material characteristics and features of atmospheric absorption spectrum. HRC features a good waterproof ability, strong oil resistance, abrasion resistance, and aging resistance. When it was painted on the surface of the dense-graded asphalt concrete, the pavement temperature could be reduced by approximately 9°C in hot seasons. The comprehensive pavement performance was evaluated through the following tests: antiskid, accelerated abrasion, freeze-thaw cycle, and permeability. The results show the asphalt concrete pavement with adopting HRC has a strong abrasion resistance, a good resistance to temperature fluctuation, and significantly reduces water damage. The skid-resistant ceramic granular should be added in the dense-graded asphalt pavement with HRC, which was show...

Functional SiO2–TiO2–PEG hybrid resin by direct chelation with catecholic compound

The mesoporous inorganic–organic SiO2–TiO2–PEG hybrid resin systems with various useful functionalities were directly synthesized by a binary sol–gel reaction of TEOS–TiCl4 and the subsequent chelation with a chatecholic compound (dihydroxy benzene), dihydroxy-m-benzenedisulfonic acid disodium salt, on the surface Ti ion of the ordered mesoporous SBA-15 network structure, respectively. Moreover, the hybrid resins consisting of polyethylene glycol and a silane coupling agent exhibited the controlled wettability, excellent coating processibility on various substrates with strong abrasion resistance. Furthermore, the transparent and low viscous resin showed the successful performance to fabricate various nanoscale patterns with the feature size down to 170 nm by imprint lithography. Based on the excellent patternability, nanofluidics with 100 nm of the narrowest dimension channel height was fabricated to employ a capillary electrophoresis for separation DNAs without gel matrix. In addition, the presence of sulfonic acid in the resin also showed the solid acid catalytic performance. These results reveal that the developed hybrid materials are very useful as an imprint resin as well as versatile microchemical applications.

Abrasion-resistant solgel antireflective films with a high laser-induced damage threshold for inertial confinement fusion

To prepare abrasion-resistant antireflective (AR) films for inertial confinement fusion, four solgel routes have been investigated on polysiloxane-modified and polyvinylalcohol- (PVA-) modified SiO2 sols. As confirmed with a transmissive electron microscope, different fractal structure characteristics of the modified SiO2 particles are disclosed by small-angle x-ray scattering technology. And it is these special fractal characteristics that determine the performance of AR films on the level of internal microstructure. A Si29 magic angle spinning and nuclear magnetic resonance study has been successfully applied in explaining the fractal microstructure and its relation to the laser-induced damage threshold (LIDT) of AR films. The films modified by PVA120000 or acetic acid-catalyzed polysiloxane have higher LIDTs than those films modified by PVA16000 or hydrochloride acid-catalyzed polysiloxane. The films from PVA-modified SiO2 sols have a stronger abrasion resistance but lower antireflection than those films from polysiloxane-modified SiO2 sols. In addition, the films from polysiloxane-modified SiO2 sols can possess high transmittance and high LIDT if the polysiloxane synthesis condition is appropriately chosen, but the abrasion resistance is not as good as that from PVA modification. If strong abrasion resistance is necessary, a possible resolution may be to choose a more appropriate hydrophilic polymer than PVA. If not, polysiloxane-modified silica sol can also work when polysiloxane is synthesized under acetic acid catalysis.