A method of manufacturing a coated reinforcing fiber for use in Ceramic Matrix Composites, the method comprising pre-oxidizing a plurality of silicon-based fibers selected from the group consisting of silicon carbide (SiC) fibers, silicon nitride (Si.sub.3N.sub.4) fibers, SiCO fibers, SiCN fibers, SiCNO fibers, and SiBCN fibers at between 700 to 1300 degrees Celsius in an oxidizing atmosphere to form a silica surface layer on the plurality of silicon-based fibers, forming a plurality of pre-oxidized fibers; applying a rare earth orthophosphate (REPO.sub.4) coating to the plurality of pre-oxidized fibers; and heating the plurality of REPO.sub.4 coated pre-oxidized fibers at about 1000-1500 degrees Celsius in an inert atmosphere to react the REPO.sub.4 with the silica surface layer to form a rare earth silicate or disilicate. The pre-oxidizing step may be 0.5 hours to about 100 hours. The heating step may be about 5 minutes to about 100 hours.

A spark plug connecting element. The spark plug connecting element includes a first contact element and a second contact element. A resistor element is situated between the first contact element and the second contact element. The first contact element and the second contact element have a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m and the resistor element has a specific conductivity of 10.sup.−3 S/m to 10.sup.1 S/m.

The invention relates to a method for treating magnesia-carbon products.

A silicide-based composite material is disclosed, comprising a silicide of Mo, B, W, Nb, Ta, Ti, Cr, Co, Y, or a combination thereof, Si3N4, and at least an oxide, as well as and a process for producing the same.

The invention relates to a spark plug connecting element, which includes a first contact element (9a) and a second contact element (9b), a resistor element (8) being situated between the first contact element (9a) and the second contact element (9b), the first contact element (9a) and the second contact element (9b) having a specific conductivity of 10.sup.2 S/m to 10.sup.8 S/m and the resistor element (8) having a specific conductivity of 10.sup.−3 S/m to 10.sup.1 S/m.

An example article according to the present disclosure includes, among other possible things, a metallic substrate, and a bond coat on the metallic substrate. The bond coat includes a matrix phase, gettering particles in the matrix phase, wherein the gettering particles are reactive with oxidants, and a dispersion of matrix modifier particles in the matrix phase. The example article also includes a diffusion barrier between the bond coat and the metallic substrate, wherein the diffusion barrier is configured to inhibit diffusion of components from the bond coat into the metallic substrate. An example composite material and method of applying a barrier to a substrate are also disclosed.

An oxidation protection system disposed on a substrate is provided, which may comprise a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition and a strengthening compound comprising boron nitride, a metal oxide, and/or silicon carbide.

An oxidation protection system disposed on a substrate is provided, which may comprise a base layer comprising a first pre-slurry composition comprising a first phosphate glass composition, and/or a sealing layer comprising a second pre-slurry composition comprising a second phosphate glass composition and a strengthening compound comprising boron nitride, a metal oxide, and/or silicon carbide.

An article including carbon-carbon composite substrate may be treated with an antioxidant coating prior to use in an oxidizing environment. The antioxidant coating may be configured to reduce oxidation at an external surface of the C-C composition and reduce ingress of oxidants into pores or other open passages defined by the C-C composite substrate to avoid internal oxidation. An example article includes a C-C composite substrate, a bond coat, and an antioxidant coating. The C-C composite substrate defines a friction surface and a non-friction surface. The bond coat is disposed on the non-friction surface. The antioxidant coating may be disposed on at least a portion of the bond coat. The antioxidant coating may include ytterbium disilicate and a sintering aid.

Systems and methods for forming an oxidation protection system on a composite structure are provided. In various embodiments, an oxidation protection system disposed on a substrate may comprise a boron-silicon-glass layer or a boron layer and a silicon layer. The boron-silicon-glass layer, boron layer, the silicon layer, or a pretreatment layer may include an oxygen reactant compound.