Abstract: A hypersonic refractory material, including a refractory leading edge portion for a hypersonic vehicle and a high emissivity oxide coating adhered to the refractory leading edge portion. The high emissivity oxide coating is ZrB2 doped with a cation dopant material selected from the group including Sm, Tm, and mixtures thereof. The cation dopant material is present in a concentration of between 3 mole percent and 8 mole percent.

Abstract: A hypersonic refractory material, including a refractory leading edge portion for a hypersonic vehicle and a high emissivity oxide coating adhered to the refractory leading edge portion. The high emissivity oxide coating is ZrB2 doped with a cation dopant material selected from the group including Sm, Tm, and mixtures thereof. The cation dopant material is present in a concentration of between 3 mole percent and 8 mole percent.

Abstract: In some examples, an article may include a substrate and a coating on the substrate. The substrate may include a superalloy, a ceramic, or a ceramic matrix composite. The coating may include a layer comprising a matrix material and a plurality of nanoparticles. The matrix material may include at least one of silica, zirconia, alumina, titania, or chromia, and the plurality of nanoparticles may include nanoparticles including at least one of yttria, zirconia, alumina, or chromia. In some examples, an average diameter of the nanoparticles is less than about 400 nm.

Abstract: In some examples, an article may include a substrate and a coating on the substrate. The substrate may include a superalloy, a ceramic, or a ceramic matrix composite. The coating may include a layer comprising a matrix material and a plurality of nanoparticles. The matrix material may include at least one of silica, zirconia, alumina, titania, or chromia, and the plurality of nanoparticles may include nanoparticles including at least one of yttria, zirconia, alumina, or chromia. In some examples, an average diameter of the nanoparticles is less than about 400 nm.

Abstract: In some examples, an article may include a substrate and a coating on the substrate. The substrate may include a superalloy, a ceramic, or a ceramic matrix composite. The coating may include a layer comprising a matrix material and a plurality of nanoparticles. The matrix material may include at least one of silica, zirconia, alumina, titania, or chromia, and the plurality of nanoparticles may include nanoparticles including at least one of yttria, zirconia, alumina, or chromia. In some examples, an average diameter of the nanoparticles is less than about 400 nm.

Abstract: The present disclosure relates to novel boron carbide (B4C) composite material and the method of making and using the novel boron carbide (B4C) composite.

Abstract: The present disclosure relates to boron carbide (B4C) composite material and the method of making and using the boron carbide (B4C) composite.

Abstract: A hypersonic refractory material, including a refractory leading edge portion for a hypersonic vehicle and a high emissivity oxide coating adhered to the refractory leading edge portion. The high emissivity oxide coating is selected from the group including Sm2O3, Tm2O3, Yb2O3, Gd2O3, and mixtures thereof, and the refractory leading edge portion includes up to about 15 mole percent of a cation dopant selected from the group including Sm2O3, Tm2O3, Yb2O3, Gd2O3, and mixtures thereof, with the remainder being selected from the group including ZrB2, HfB2, and mixtures thereof. The high emissivity coating is formed by oxidation of cation dopant at elevated temperatures.

Abstract: Devices and methods for fabrication of a multiscale porous high-temperature heat exchanger for high-temperature and high-pressure applications are disclosed. The heat exchanger can include a core with macrochannels formed in a checkerboard pattern to facilitate alternative flow of working fluid having hot and cold temperatures between adjacent macrochannels. Each macrochannel can include a two-dimensional microchannel array that further distributes flow throughout the heat exchanger to enhance heat transfer and mechanical strength without significant pressure drop penalty. The heat exchanger can further include a header integrated therewith to distribute working fluid flowing through the heat exchanger through the outlets such that it flows evenly therethrough. Methods of fabricating heat exchangers of this nature are also disclosed.

Abstract: Methods of manufacturing carbon/carbon preforms and carbon/carbon composites formed therefrom. Such a method includes extruding a polymer composite material using an extrusion deposition additive manufacturing process to form a preform, and heating the preform via pyrolysis to form the carbon/carbon composite.

Abstract: A method for ambient temperature injection molding of ceramic bodies, including combining ceramic powder, water, and dispersant to yield a first admixture, combining water and water soluble polymer to yield a second admixture, combining the first and second admixture to yield a homogeneous slurry, flowing the homogeneous slurry into a mold to yield a molded green body, and removing the green body from the mold, all of which are performed at room temperature. The slurry exhibits yield psuedoplastic flow characteristics and contains more than 50 weight percent ceramic powder and less than 5 weight percent water soluble polymer.

Abstract: The present disclosure provides a transparent alumina-based plate, and a hot-pressing method to make the transparent alumina-based plate from platelet alumina. Alumina powder with a platelet morphology was hot-pressed to transparency with pre-load pressures of about 0-8 MPa, maximum temperatures of about 1750-1825° C., maximum pressures of about 2.5-80 MPa, and isothermal hold times of 1-7 hours. A novel alumina-based plate has been prepared, wherein the plate has a thickness of 2-5 mm, an in-line transmission of at least 60-75% for a light with a wavelength range of 645-2500 nm, an in-line transmission variance of <15% over the wavelength range of 645-2500 nm, and a relative density of 99.00-99.95%.