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At least 487 records · Page 27

Corrosion Behavior of Laser-Interference Structured AA2024 Coated with a Chromate-Containing Epoxy Primer

In this study, the corrosion behavior of laser-interference treated AA2024-T3 specimens, which are coated with a primer, is presented. The surface of as-received AA2024-T3 specimens were laser-interference structured by splitting the primary beam of a Q-switched Nd:YAG pulsed nanosecond laser into two beams and focusing them to the same spot on the specimen surface. After being stored in plastic cases for up to 70 d, without any additional cleaning, the specimens were spray painted with a chromate-containing epoxy primer, CA7233, compliant to MIL-PRF-23377 Type I Class C2 specification. The corrosion behavior of laser-interference specimens was assessed against that of specimens prepared by chromated conversion coating and sulfuric acid anodizing treatments. After the ASTM B117 corrosion exposure, it was found that the laser processed specimens exhibited only few blisters. On one hand, most specimens prepared at a laser fluence of 1.78 J/cm 2 , without any additional chemical cleaning, were found to develop one very small blister after only 96 h of exposure. However, the growth of these blisters was not significant even after 1,000 h of salt spray exposure. On the other hand, only a fraction of the specimens prepared at a laser fluence of 1.24 J/cm 2 and acetone wiped right after the laser structuring were found to develop several tiny blisters after 790 h and longer exposure. Overall, it was found that the corrosion damage was minimized at a laser rastering speed of 4 mm/s, a condition for which only 33% of specimens developed very minor corrosion damage. Furthermore, the ASTM D1654 creepage ratings, which was used to evaluate the corrosion damage along the scribe lines, were found to be at least nine for all coated panels. These results indicate that the laser-interference technique with the additional acetone wiping has the potential to be further developed as a nonchemical surface preparation technique for chromate-containing epoxy primers coating systems.

36 MATERIALS SCIENCE↗

Advanced high temperature environmental barrier coating for SiC/SiC ceramic matrix composites

Advanced environmental barrier coating bond coat systems with higher temperature capabilities and environmental resistance are disclosed. These bond coat systems can be applied to ceramic substrates such as SiC/SiC ceramic matrix composite substrates, and can provide protection from extreme temperature, mechanical loading and environmental conditions, such as in high temperature gas turbines. Example bond coat systems can include either an advanced silicon/silicide component, an oxide/silicate component, or a combination thereof.

36 MATERIALS SCIENCE↗

Superhydrophobic coating and process of making same

An improved superhydrophobic coating and a process of making it is provided herein. More particularly, a robust superhydrophobic coating is produced by using carbon dioxide to enhance the integration of a binder material into the superhydrophobic coating. The carbon dioxide may be used to infiltrate and fill the interstitial voids of a superhydrophobic material, such as diatomaceous earth. Consequently, occupying these voids in the superhydrophobic material effectively blocks other components (e.g., binders) from entering the voids. As a result, the coating formulations of the present invention are more robust and may strongly adhere to the substrates to which they are applied.

36 MATERIALS SCIENCE↗

Coated U3Si2 pellets with enhanced water and steam oxidation resistance

A method of forming a water resistant boundary on a fissile material for use in a water cooled nuclear reactor is described. The method comprises coating the fissile material, such as a pellet of U3Si2 and/or the grain boundaries, to a desired thickness with a suitable coating material, such as atomic layer deposition or a thermal spray process. The coating material may be any non-reactive material with a solubility at least as low as that of UO2. Exemplary coating materials include ZrSiO4, FeCrAl, Cr, Zr, Al—Cr, CrAl, ZrO2, CeO2, TiO2, SiO2, UO2, ZrB2, Na2O—B2O3—SiO2—Al2O3 glass, Al2O3, Cr2O3, carbon, and SiC, and combinations thereof. The water resistant layer may be overlayed with a burnable absorber layer, such as ZrB2 or B2O3—SiO2 glass.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Asymmetric articles with a porous substrate and a polymeric coating extending into the substrate and methods of making the same

Asymmetric articles are described including a porous substrate with two opposing major surfaces and a porous structure extending between the surfaces, and a polymeric coating on one of the major surfaces and extending into the porous structure to a depth of the porous structure. Methods for making an asymmetric composite article are also provided, including providing a porous substrate, treating the porous substrate with a plasma treatment or a corona treatment from one major surface to a depth of the porous structure between the two major surfaces. The method further includes applying a coating solution to the treated porous substrate and drying the coating solution to form a composite asymmetric composite article having a polymeric coating on one major surface and extending into the porous structure to the depth of the treated porous structure.

36 MATERIALS SCIENCE↗

Advanced high temperature environmental barrier coating systems for SiC/SiC ceramic matrix composites

Advanced environmental barrier coating bond coat systems with higher temperature capabilities and environmental resistance are disclosed. These bond coat systems can be applied to ceramic substrates such as SiC/SiC ceramic matrix composite substrates, and can provide protection from extreme temperature, mechanical loading and environmental conditions, such as in high temperature gas turbines. Example bond coat systems can include either an advanced silicon/silicide component, an oxide/silicate component, or a combination thereof.

36 MATERIALS SCIENCE↗

Protective anode coatings for high energy batteries

Materials for coating a metal anode in a high energy battery, anodes coated with the materials, and batteries incorporating the coated anodes are provided. Also provided are batteries that utilize the materials as electrolytes. The coatings, which are composed of binary, ternary, and higher order metal and/or metalloid oxides, nitrides, fluorides, chlorides, bromides, sulfides, and carbides limit the reactions between the electrolyte and the metal anode in a battery, thereby improving the performance of the battery, relative to a battery that employs a bare anode.

Hegde, Vinay Ishwar↗

Pitting resistant carbon coatings

A hydrogenated diamond-like coating (“H-DLC”) for metallic substrates provides improved reliability. The H-DLC is relatively soft and elastic. Unlike hard and/or inelastic coatings in the prior art, the present coatings do not exhibit a loss of adhesion (delamination). A bonding layer may be used between the metallic substrate and the H-DLC. H-DLC coatings can, for example, be used in bearings and gears to reduce the occurrence of micropits and, ultimately, product failure.

Erylimaz, Osman L.↗

High-strength aluminum alloy coatings, deformation layers and methods of making the same

A high-strength aluminum alloy coating. The coating includes aluminum, 9R phase, fine grains, nanotwins, stacking faults, and a solute capable of stabilizing the 9R phase, the fine grains, and the stacking faults. A method of making a high-strength aluminum alloy coating on a substrate. The method includes, depositing the constituents of an aluminum alloy on a substrate such that the deposit forms a high-strength aluminum alloy coating containing 9R phase, fine grains, nanotwins, and stacking faults. A high-strength deformation layer in and on a casting of an aluminum alloy containing 9R phase, fine grains, nanotwins, stacking faults, and a solute capable of stabilizing the PR phase, the fine grains, and the stacking faults. A method of making a high-strength deformation layer in and on a casting of an aluminum alloy by deforming the alloy such that deformation layer contains 9R phase, fine grains, nanotwins, and stacking faults.

Zhang, Xinghang↗

Ultra-low reflectance broadband omni-directional anti-reflection coating

An anti-reflection coating has an average total reflectance of less than 10%, for example less than 5.9% such as from 4.9% to 5.9%, over a spectrum of wavelengths of 400-1100 nm and a range of angles of incidence of 0-90 degrees with respect to a surface normal of the anti-reflection coating. An anti-reflection coating has a total reflectance of less than 10%, for example less than 6% such as less than 4%, over an entire spectrum of wavelengths of 400-1600 nm and an entire range of angles of incidence of 0-70 degrees with respect to a surface normal of the anti-reflection coating.

Chhajed, Sameer↗

Metal fluoride passivation coatings prepared by atomic layer deposition for Li-ion batteries

The fabrication of robust interfaces between transition metal oxides and non-aqueous electrolytes is one of the great challenges of lithium ion batteries. Atomic layer deposition (ALD) of aluminum tungsten fluoride (AlWxFy) improves the electrochemical stability of LiCoO2. AlWxFy thin films were deposited by combining trimethylaluminum and tungsten hexafluoride. in-situ quartz crystal microbalance and transmission electron microscopy studies show that the films grow in a layer-by-layer fashion and are amorphous nature. Ultrathin AlWxFy coatings (<10 Å) on LiCoO2 significantly enhance stability relative to bare LiCoO2 when cycled to 4.4 V. The coated LiCoO2 exhibited superior rate capability (up to 400 mA/g) and discharge capacities at a current of 400 mA/g were 51% and 92% of the first cycle capacities for the bare and AlWxFy coated materials. These results open new possibilities for designing ultrathin and electrochemically robust coatings of metal fluorides via ALD to enhance the stability of Li-ion electrodes.

Mane, Anil U.↗

Method of enhancing a DLC coated surface for enhanced multipaction resistance

A method for creating an enhanced multipaction resistant diamond-like coating (DLC) coating with lower Secondary Electron Emission (SEE) properties is performed on an initial surface by etching a DLC coating deposited on the surface after deposition and optionally creating interlayers to enhance adhesion mechanical properties between the DLC coating and the initial surface.

Nichol, Robert Michael↗

Ductile coatings on additive manufactured components

A method of forming a coated component using an additive manufacturing system including building a body portion of the component on a build plate. An outer surface of the body portion can include an indentation resulting from the additive manufacturing system. The method further includes performing at least one post-build process on the body portion. The method yet further includes forming a coating layer on an outer surface of the processed body portion. The coating layer may surround a portion of the body component and may impregnate the indentation. A thickness of the coating layer may be a function of at least one of surface roughness, size of the indentation, or a diameter of particles used to build the additive manufactured bracket.

Racca, Stephen D.↗

Protective anode coatings for high energy batteries

Materials for coating a metal anode in a high energy battery, anodes coated with the materials, and batteries incorporating the coated anodes are provided. Also provided are batteries that utilize the materials as electrolytes. The coatings, which are composed of binary, ternary, and higher order metal and/or metalloid oxides, nitrides, fluorides, chlorides, bromides, sulfides, and carbides limit the reactions between the electrolyte and the metal anode in a battery, thereby improving the performance of the battery, relative to a battery that employs a bare anode.

Hegde, Vinay Ishwar↗

Thermal barrier coatings for internal combustion engines

A thermal barrier coating for an internal combustion engine includes an insulating thermal spray coating, where a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form and the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed.

Jordan, Eric↗

Battery electrode coatings applied by waterborne electrodeposition

The present invention is directed towards an electrodepositable coating composition comprising (a) a fluoropolymer; (b) an electrochemically active material and/or electrically conductive agent; (c) a pH-dependent rheology modifier; and (d) an aqueous medium comprising water; wherein water is present in an amount of at least 45% by weight, based on the total weight of the electrodepositable coating composition. Also disclosed herein is a method of coating a substrate, as well as coated substrates and electrical storage devices.

Oakes, Landon J.↗

Thermal barrier coatings for internal combustion engines

A thermal barrier coating for an internal combustion engine includes an insulating thermal spray coating, where a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form and the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed.

Jordan, Eric↗

Water soluble barrier coatings for washout tooling for a composite layup

A washout tooling for a composite layup is provided. The washout tooling comprises a casting mold having an exterior surface. The casting mold comprises a particulate material and a water-soluble binder. The casting mold is adapted to break down in the presence of an aqueous solution. The washout tooling further comprises a water-soluble coating layer overlying the exterior surface. The water-soluble coating layer is adapted to break down in the presence of an aqueous solution. The washout tooling further comprises a curable composite layer overlying the water-soluble coating layer. The water-soluble coating layer minimizes contact between the particulate material and the curable composite layer.

Saito, Tomonori↗