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 unitary radome layer assembly is provided and includes a first nanocomposite formulation and a second nanocomposite formulation. The first and second nanocomposite formulations are provided together in a unitary radome layer with respective distribution gradients.

A unitary radome layer assembly is provided and includes a first nanocomposite formulation and a second nanocomposite formulation. The first and second nanocomposite formulations are provided together in a unitary radome layer with respective distribution gradients.

An article includes a body having a plasma-sprayed ceramic coating on a surface thereof. The body can be formed of at one least one of the following materials: Al, Al.sub.2O.sub.3, AlN, Y.sub.2O.sub.3, YSZ, or SiC. The plasma-sprayed ceramic coating can include at least one of Y.sub.2O.sub.3, Y.sub.4Al.sub.2O.sub.9, Y.sub.3Al.sub.5O.sub.12 or a solid-solution of Y.sub.2O.sub.3 mixed with at least one of ZrO.sub.2, Al.sub.2O.sub.3, HfO.sub.2, Er.sub.2O.sub.3, Nd.sub.2O.sub.3, Nb.sub.2O.sub.5, CeO.sub.2, Sm.sub.2O.sub.3 or Yb.sub.2O.sub.3. The plasma-sprayed ceramic coating can further include splats.

An article includes a body having a plasma-sprayed ceramic coating on a surface thereof. The body can be formed of at one least one of the following materials: Al, Al.sub.2O.sub.3, AlN, Y.sub.2O.sub.3, YSZ, or SiC. The plasma-sprayed ceramic coating can include at least one of Y.sub.2O.sub.3, Y.sub.4Al.sub.2O.sub.9, Y.sub.3Al.sub.5O.sub.12 or a solid-solution of Y.sub.2O.sub.3 mixed with at least one of ZrO.sub.2, Al.sub.2O.sub.3, HfO.sub.2, Er.sub.2O.sub.3, Nd.sub.2O.sub.3, Nb.sub.2O.sub.5, CeO.sub.2, Sm.sub.2O.sub.3 or Yb.sub.2O.sub.3. The plasma-sprayed ceramic coating can further include splats.

An article comprises a body and a conformal protective layer on at least one surface of the body. The conformal protective layer is a plasma resistant rare earth oxide film having a thickness of less than 1000 μm, wherein the plasma resistant rare earth oxide film is selected from a group consisting of an Er—Y composition, an Er—Al—Y composition, an Er—Y—Zr composition, and an Er—Al composition.

An article comprises a body and a conformal protective layer on at least one surface of the body. The conformal protective layer is a plasma resistant rare earth oxide film having a thickness of less than 1000 μm, wherein the plasma resistant rare earth oxide film is selected from a group consisting of an Er—Y composition, an Er—Al—Y composition, an Er—Y—Zr composition, and an Er—Al composition.

A binder for an injection moulding composition, the binder includes, in percentage by mass and for a total of 100%: 35% to 60% of a component (a), or polymer base, made of a polymer or a mixture of polymers, each of the polymer being non-amphiphilic and having a mass average molar mass greater than or equal to 5,000 g/mol, 30% to 55% of a component (b), or wax, made of a polymer or a mixture of polymers, each of the polymer being non-amphiphilic and having a mass average molar mass less than 5,000 g/mol, and less than 10% of an amphiphilic component (c), or surfactant, and less than 10% of other components (d). The polymer base comprising 2% to 15% of a styrene-ethylene-butylene-styrene copolymer (SEBS), in percentage by mass based on the mass of the binder.

An article comprises a body and a conformal protective layer on at least one surface of the body. The conformal protective layer is a plasma resistant rare earth oxide film having a thickness of less than 1000 μm, wherein the plasma resistant rare earth oxide film consists essentially of 40 mol % to less than 100 mol % of Y.sub.2O.sub.3, over 0 mol % to 60 mol % of ZrO.sub.2, and 0 mol % to 9 mol % of Al.sub.2O.sub.3.

An article comprises a body and a conformal protective layer on at least one surface of the body. The conformal protective layer is a plasma resistant rare earth oxide film having a thickness of less than 1000 μm, wherein the plasma resistant rare earth oxide film consists essentially of 40 mol % to less than 100 mol % of Y.sub.2O.sub.3, over 0 mol % to 60 mol % of ZrO.sub.2, and 0 mol % to 9 mol % of Al.sub.2O.sub.3.