Methods and apparatus for producing bulk silicon carbide and producing silicon carbide coatings are provided herein. The method includes feeding a mixture of silicon carbide and ceramic into a plasma sprayer. The plasma generates a stream towards a substrate forming a bulk material or optionally a coating on the substrate such as an article upon contact therewith. In embodiments, the substrate can be removed, leaving a component part fabricated from bulk silicon carbide.

A thermoelectric conversion material includes Mg.sub.2Si.sub.xSn.sub.1−x (where 0.3≤X≤1) and a boride containing one or two or more metals selected from titanium, zirconium, and hafnium. Further, it is preferable that the boride is one or two or more selected from TiB.sub.2, ZrB.sub.2, and HfB.sub.2.

In some embodiments, a ceramic armor product includes: a ceramic powder; an at least one metal-based additive; and a density of 4.3-4.7 g/cc, wherein the ceramic armor product is substantially lacking grain orientation. In some embodiments, a ceramic armor product, includes: a ceramic powder, wherein the ceramic powder is titanium diboride (TiB2); an at least one metal-based additive, wherein the at least one metal based additive comprises elements ranging from atomic numbers 21 through 30, 39 through 51, and 57 through 77; and a density of 4.3-4.7 g/cc, wherein the ceramic armor product is substantially lacking grain orientation.

The novel process enables designing of raw materials and processing parameters, enabling synergistic and simultaneous chemical reactions among the various reactants of the design mix of chemical precursor of brine sludge which includes barium sulphate, magnesium hydroxide, calcium carbonate, sodium chloride, silica, aluminum containing compounds necessary for developing highly efficient shielding phases leading to homogenous matrix of shielding materials.

A ceramic matrix composite includes a substrate which contains a fibrous body made of silicon carbide fiber, and a matrix which is formed in the substrate, and which contains silicon carbide and a silicon material made of silicon or a binary silicon alloy.

A method for making a ceramic matrix composite component includes densifying a fibrous preform of the component with a ceramic matrix to form an intermediate component; infiltrating a hole in the intermediate component with an infiltrate material comprising a solid and a metallic alloy whose reaction forms a carbide, silicide, boride or combination thereof, heating the infiltrate material to a temperature in excess of a melting point of the metallic alloy; and sequentially cooling regions of the hole starting from an interior end of the hole to the outer surface of the intermediate component to form a solidified through-thickness reinforcement element. The hole extends in a through-thickness direction and is open to an exterior surface of the intermediate component.

A multilayer electronic component includes a body including a dielectric layer and an internal electrode; and an external electrode disposed on the body and connected to the internal electrode, wherein the dielectric layer includes first and second grains, wherein the first grain has a core-shell structure including a shell having an atomic ratio of 2*Sn/(Ba+Ti+Sn) or 2*Hf/(Ba+Ti+Hf) to be 1.0% or more and 5.0% or less, and a core having an atomic ratio of 2*Sn/(Ba+Ti+Sn) and 2*Hf/(Ba+Ti+Hf) to be less than 1.0%, and the second grain has an atomic ratio of 2*Sn/(Ba+Ti+Sn) and 2*Hf/(Ba+Ti+Hf) to be less than 1.0%, and wherein an area occupied by the first grain in an entire area of the first and second grains is 28.3-82.3%.

Composite structures are provided whose composite matrix is a fully-dense (greater than 95%) magnesium oxide-containing phase and whose entrained phase, by virtue of its' decomposition temperature or chemical reactivity, would otherwise not be fabricable. Notably, a methodology is provided whereby a range of composite structures are formed by applying an advanced manufacturing technique and a blend of ceramic powder whose sintering is enhanced by small amounts of a metal halide sintering aid. This methodology and process significantly lowers the processing temperature of refractory ceramics such as magnesium oxide allowing formation of ceramic bodies incorporating phases such as metal hydrides, fragile ceramic phases, and highly reactive species such as beryllides. In all cases, the final product is substantially-free, or even devoid, of the metal halide sintering aid, resulting in a phase-pure ceramic matrix composed of the host phase and the entrained phase.

Provided are 5-layered MXene materials having the formulas M.sub.5X.sub.4T.sub.x; (M′aM″b)X.sub.4T.sub.x (where a+b=5); and (M′.sub.aM″.sub.b).sub.5X.sub.4T.sub.x (where a+b=1). Also provided are related methods, compositions, and applications.

A dielectric ceramic composition includes a barium titanate (BaTiO.sub.3)-based base material main ingredient and an accessory ingredient, the accessory ingredient including dysprosium (Dy) and praseodymium (Pr) as first accessory ingredients. A content of the Pr satisfies 0.233 mol≤Pr≤0.699 mol, based on 100 mol of the barium titanate base material main ingredient.