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At least 361 records · Page 20

Development of Refractory Alloys and Refractory Coatings for Advanced Nuclear Reactors

The next generation of nuclear reactors will benefit from materials that enable operation at higher temperatures (>500°C), higher irradiation doses (up to 200 displacements per atom (dpa)), and the use of more corrosive and reactive coolants. This work package represents the first experimental steps towards a longer-term effort to develop refractory materials for nuclear energy applications which will enable operation under these conditions. Specifically, this work package focuses on additive manufacturing of refractories as both a refractory liner coating deposited onto the interior surface of a metallic tubular backbone and as bulk refractory alloys. During fiscal year 23 (FY23), several refractory metal coating systems and bulk alloys were examined and selected using a decision criteria matrix. The refractory metal coating systems included molybdenum, tungsten, and zirconium as refractory coatings on backbones of either carbon-carbon (C/C) or silicon carbide-silicon carbide (SiC/SiC) ceramic matrix composites. The bulk refractory alloys included C-103, WTa, and WNiFe as bulk alloys. During FY24 additional bulk refractory alloys and metallic backbones were evaluated using the decision criteria matrix based on input from the AMMT leadership team. These included 316 SS and 316H SS for the metallic backbones and Mo-La, Ta, and Nb1Zr as bulk refractory alloys. The primary focus for the FY24 effort was placed on establishing the capabilities to deposit refractory coatings based on the results of the scoring in the decision criteria matrix and finalizing the additively manufactured TZM studies which were incorporated into the AMMT program from the microreactor program. Further efforts were dedicated to establishing the capabilities to additively manufacture down-selected bulk refractory alloys.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Improving Stability of an Optical Fiber pH Sensor with a Calcined Polyethylenimine-Coating at High Pressures and Temperatures

With an increased interest in subsurface gas storage technology for various energy applications, monitoring wellbore structural stability and subsurface geochemistry has become more pressing, and pH is a key parameter to measure. As high pressure and elevated temperatures in subsurface conditions are comparatively harsh relative to that expected for most standard pH sensor designs, any pH monitoring hardware must be designed for extended exposure to high pressures and temperatures. We previously reported that an optical fiber pH sensor functionalized with a calcined polyethylenimine coating had shown some promise as a high temperature and pressure pH sensor but with some drifting when operating for longer than 8 hours. In this paper, we investigated the coating composition and potential cause of the drifting and improved the stability of the prepared coating to minimize sensor drift under simulated wellbore conditions. Scanning electron microscopy (SEM) had previously shown moderate cracking at high pressures over short tests. By applying X-ray photoelectron spectroscopy (XPS) to characterize the sensor coating before and after one week of testing in an H2/CH4 gas blend at 80 °C and 900 psi, a compositional change in the coating was observable, which may indicate susceptibility to alteration by subsurface gas storage conditions. Non-reducing (CH4, N2) environments were also tested, and confirmed that both temperature and pressure were also contributing to the drift.

energy infrastructure↗

Computational design of high entropy alloy coating for hydrogen turbine applications

This project aims to develop novel high entropy alloy (HEA)-based coatings to protect critical components in hydrogen-fueled turbine power system. The HEA-coatings will demonstrate superior performance in hydrogen combustion environment to commercial NiCoCrAlY coating in current natural gas turbine system. The HEA coating facilitates the formation of a protective scale of alpha-alumina to slow down the inward diffusion of oxidizing species and the outward diffusion of metal elements, and possesses ultrahigh corrosion and spallation resistance to prolong the service lifetime of critical components in hydrogen turbine power system. Aimed to accelerate the discovery of novel HEA coating compositions, high throughput computational modeling including CALPHAD and density functional theory and machine learning are performed to predict phase stability, oxygen permeability, oxidation rate constant, coefficient of thermal expansion, and mechanical properties. Based on the modeling and machine learning prediction, experimental validation is performed. Preliminary results will be presented and approaches to minimize oxidation will be discussed.

alloy design↗

High Entropy Rare-earth Oxide (HERO) Coatings for Refractory Alloys

The HERO coating was developed to protect refractory alloys for application in the harsh hot section of the turbine engine environment addressing ARPA-E ULTIMATE Project Topic 2: Coating Development. The effort was both innovative in its utilization of high entropy rare earth oxides as well as transformational in our approach: holistic design of a single layer thermal/environmental barrier coating (T/EBC) for refractory alloys, with an excellent coefficient of thermal expansion (CTE) match to the alloy substrate, chemical compatibility with the underlying alloy, low oxidant permeability, stability in combustion environments, low thermal conductivity, thermal shock resistance, and resistance to degradation by siliceous debris (calcium magnesium alumino-silicates-CMAS). The high entropy rare earth oxide approach enables two critical coating properties: tailoring CTE match to the substrate and, most significantly, substantially reduced thermal conductivity. The summation of these proposed coating capabilities goes well beyond the technical requirements specified in the ULTIMATE program objectives, and additionally is essential for a successful first stage turbine blade application.

36 MATERIALS SCIENCE↗

Uncertainties in the effects of organic aerosol coatings on polycyclic aromatic hydrocarbon concentrations and their estimated health effects

We used the CAM5 model to examine how different particle-bound polycyclic aromatic hydrocarbon (PAH) degradation approaches affect the spatial distribution of benzo(a)pyrene (BaP). Three approaches were evaluated: NOA (no effect of OA coatings state on BaP), shielded (viscous OA coatings shield BaP from oxidation under cool and dry conditions) and ROI-T (viscous OA coatings slow BaP oxidation in response to temperature and humidity). Results show that BaP concentrations vary seasonally, influenced by emissions, deposition, transport and degradation approach, all of which are influenced by meteorological conditions. All simulations predict higher population-weighted global average (PWGA) fresh BaP concentrations during December–January–February (DJF) compared to June–July–August (JJA), due to increased emissions from household activities and reduced removal processes during colder months. The shielded and ROI-T approaches, which account for OA coatings, result in 2–6 times higher BaP concentrations in DJF compared to NOA. The shielded simulation predicts the highest PWGA fresh BaP concentration (1.3 ng m −3 ), with 90 % of BaP protected from oxidation. In contrast, the ROI-T approach forecasts lower concentrations in middle to low latitudes, as it assumes less effective OA coatings under warmer, more humid conditions. Evaluations against observed BaP concentrations show the shielded approach performs best, with a normalized mean bias (NMB) within ± 20 %. The combined incremental lifetime cancer risk (ILCR) for both fresh and oxidized PAHs is similar across simulations, emphasizing the importance of considering both forms in health risk assessments. This study highlights the critical role of accurate degradation approaches in PAH modeling.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗

Measurement report: Role of organic coating and chemical composition on ice nucleation potential of atmospheric particles in European Arctic

Understanding the ice nucleation (IN) potential of Arctic aerosols is critical for predicting their influence on cloud formation and water cycles in this vulnerable region. This study investigates the role of particle composition, organic coatings, and aerosol sources in modulating ice nucleating particle (INPs) abundance across five aerosol samples collected at the Gruvebadet Observatory Station in Ny-Ålesund, Svalbard. The IN potential of Arctic aerosol particles was studied by investigating chemical, morphological, and INP abundance measurements. Single-particle analyses revealed distinct differences in mixing state, organic volume fraction (OVF), and organic coating morphology across samples. OVF distributions were linked to particle origin, with marine-influenced Na-rich particles often exhibiting thin organic coatings, while long-range transported particles showed thicker organic coatings. Biogenic contributions, though variable, were linked to heat-sensitive INPs, suggesting a role for labile biological macromolecules under certain meteorological conditions. Spearman rank correlation analysis between particle composition and immersion-mode INP concentrations at two freezing temperatures indicated that organic-rich and Na-rich particles were positively associated with enhanced INP abundance. However, discrepancies in INP abundance were observed for particles with thicker organic coatings, where the morphological configuration of the organic material may play a role. The results highlight that Arctic INP variability is governed not only by chemical composition but also by the morphological configuration of organic material, which can either enhance or inhibit ice nucleation depending on its abundance, distribution, thickness, and mixing state. These findings underscore the combined influence of source regions, atmospheric processing, and organic–inorganic interactions in shaping Arctic aerosol freezing behavior.

Lata, Nurun Nahar [Pacific Northwest National Labo↗

Alkali resistant optical coatings for alkali lasers and methods of production thereof

In one embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali. In another embodiment, a method for forming an alkali resistant coating includes forming two or more alternating layers of high and low refractive index oxide materials above a substrate, wherein an innermost layer of the two or more alternating layers is on an alkali-contacting side of the alkali resistant coating, and wherein the innermost layer of the two or more alternating layers comprises at least one of: alumina, zirconia, and hafnia.

36 MATERIALS SCIENCE↗

Elastic gas barrier coating compositions

An elastic gas barrier coating composition includes a barrier material dispersed in an aqueous media, a polysulfide, and a curing agent reactive with the polysulfide. When applied to a substrate and cured to form a coating, the barrier material forms a continuous phase and a polysulfide elastomer forms a discontinuous phase. An elastic gas coating is also disclosed that includes a continuous phase with a barrier material and a discontinuous phase with a polysulfide elastomer. Substrates at least partially coated with elastic gas barrier coating compositions are further disclosed.

36 MATERIALS SCIENCE↗

Durable polymer-aerogel based superhydrophobic coatings: a composite material

Provided are polymer-aerogel composite coatings, devices and articles including polymer-aerogel composite coatings, and methods for preparing the polymer-aerogel composite. The exemplary article can include a surface, wherein the surface includes at least one region and a polymer-aerogel composite coating disposed over the at least one region, wherein the polymer-aerogel composite coating has a water contact angle of at least about 140° and a contact angle hysteresis of less than about 1°. The polymer-aerogel composite coating can include a polymer and an ultra high water content catalyzed polysilicate aerogel, the polysilicate aerogel including a three dimensional network of silica particles having surface functional groups derivatized with a silylating agent and a plurality of pores.

Kissel, David J.↗

Turbomachine component with coating-capturing feature for thermal insulation

The disclosure relates to turbomachine components which include one or more coating-capturing features for thermal insulation. A turbomachine component may include: a body having an exterior surface positioned within a hot gas path (HGP) section of a turbomachine; and a coating-capturing feature mounted on the exterior surface of the body and in thermal communication with the HGP section of the turbomachine, wherein the coating-capturing feature comprises: a first member positioned on the exterior surface of the body, the first member having at least one outer sidewall defining a first perimeter of the coating-capturing feature, a second member positioned on the first member and having at least one outer sidewall defining a second perimeter of the coating-capturing feature, wherein the first member separates the second member from the exterior surface of the body, and an indentation positioned between the first and second members.

Berry, Jonathan Dwight↗

Removable smart sequestration coatings for hazardous metals

Materials are disclosed for the safe sequestration and removal of hazardous contaminants from a surface. The materials can be sprayed, rolled, painted, brushed or dip coated onto any surface and allowed to dry and/or cure at room temperature or drying/curing can be accelerated by the application of heat to form a coating that entraps the contaminant therein. The coating and the entrapped contaminant can then peeled from the surface and safely disposed of to minimize hazardous waste. The coating includes a colorimetric additive that is specific to the contaminant, the coating and the contaminant producing a visual indication of contamination.

Sampathkumaran, Uma↗

Fused anti-soiling and anti-reflective coatings

A method for applying a coating to a surface includes the step of providing a reaction mixture comprising a silicon alkoxide and an alcohol. A reaction limiting amount of water is added. The silicon alkoxides and water are allowed to react to form silica precursor particles during an initial reaction period. A coating precursor composition is prepared by adding an acid soluble in the alcohol to the reaction mixture during a second reaction period after the initial reaction period. The precursor silica particles grow to form silica nanofeatures having a major dimension that is larger than a major dimension of the silica precursor particles. The coating precursor composition is applied to a surface, and the alcohol and water are allowed to evaporate and the silica nanofeatures to adhere to the surface and form a nanostructured layer on the surface. A coating precursor composition and a coated article are also disclosed.

Lee, Dominic F.↗

Oil skimmer with oleophilic coating

A method of fabricating an coating includes providing a coating comprising a base material. The base material is coated with an inorganic material using at least one of an atomic layer deposition (ALD), a molecular layer deposition (MLD), or sequential infiltration synthesis (SIS) process. The SIS process includes at least one cycle of exposing the coating to a first metal precursor for a first predetermined time and a first partial pressure. The first metal precursor infiltrates at least a portion of the base material and binds with the base material. The coating is exposed to a second co-reactant precursor for a second predetermined time and a second partial pressure. The second co-reactant precursor reacts with the first metal precursor, thereby forming the inorganic material on the base material. The inorganic material infiltrating at least the portion of the base material. The inorganic material is functionalized with a material.

Darling, Seth B.↗

Coated fiber optic chemical and radiation sensors

Distributed fiber optic chemical and radiation sensors formed by coating the fibers with certain types of response materials are provided. For distributed chemical sensors, the coatings are reactive with the targets; the heat absorbed or released during a reaction will cause a local temperature change on the fiber. For distributed radiation sensors, coating a fiber with a scintillator enhances sensitivity toward thermal neutrons, for example, by injecting light into the fiber. The luminescent components in these materials are taken from conjugated polymeric and oligomeric dyes, metal organic frameworks with sorbed dyes, and two-photon-absorbing semiconductors. The compositions may exhibit strong gamma rejection. Other scintillators combining luminescent materials with neutron converters are available. With a multiple-layer coating, it may be possible to identify the presence of both neutrons and gamma rays, for example. Coatings may be applied during manufacture or in the field.

Lamberti, Vincent E.↗

Composition and method embodiments for plating metal coatings

Disclosed herein are embodiments of a coating composition and a method of using the same for forming metal coatings on substrates. In particular embodiments, the coating composition comprises a deep eutectic solvent and/or an ionic liquid; a metal precursor; an alkali metal salt; and an optional additive component. The coating composition and method embodiments disclosed herein provide durable, even, high-surface area coatings on various types of substrates and also can be used at low temperatures.

Hubbard, Lance R.↗

Preservation of the High Quality Factor and Accelerating Gradient of Nb3Sn-coated Cavity During Pair Assembly

Two CEBAF 5-cell accelerator cavities have been coated with Nb3Sn film using the vapor diffusion technique. One cavity was coated in the Jefferson Lab Nb3Sn cavity coating system, and the other in the Fermilab Nb3Sn coating system. Both cavities were measured at 4 K and 2 K in the vertical dewar test in each lab and then assembled into a cavity pair at Jefferson Lab. Previous attempts to assemble Nb3Sn cavities into a cavity pair degraded the superconducting properties of Nb3Sn-coated cavities. This contribution discusses the efforts to identify and mitigate the pair assembly challenges and will present the results of the vertical tests before and after pair assembly. Notably, one of the cavities reached the highest gradient above 80 mT in the vertical test after the pair assembly.

43 PARTICLE ACCELERATORS↗

Commissioning of Dedicated Furnace for Nb3Sn Coatings of 2.6 GHz Single Cell Cavities

We present the results of commissioning a dedicated furnace for Nb3Sn coatings of 2.6 GHz single cell cavities. Nb3Sn is a desired coating due to its high critical temperature and smaller surface resistance compared to bulk Nb. Usage of Nb3Sn coated cavities will greatly reduce operating costs due to decreased dependance on cryo cooling. Tin is deposited by use of a tin chloride nucleation agent and tin vapor diffusion. Analysis of the resultant coating was performed using SEM/EDS to verify successful formation of Nb3Sn. Witness samples in line of sight of the source were used in order to understand the coating efficacy.

43 PARTICLE ACCELERATORS↗

Applying protective coatings to optical fibers

Apparatus, systems, and methods that provide coats on a glass optical fiber including of an inner layer and an outer layer. The method includes two steps. First, a conductive polymer coating is applied to the optical fiber as it is being produced. Second, a protective coating is applied to that conductive polymer coating. The conductive polymer coating is applied immediately after the fiber is drawn from preform to fiber.

Calta, Nicholas P.↗