Abstract: A multilayer interface coating for composite material fibers includes a first coating layer deposited onto a fiber and a second coating layer deposited onto the first coating layer.

Abstract: A composite component and methods for making the same are disclosed in this paper. The composite component includes a matrix material and reinforcements suspended in the matrix material. The reinforcements include fibers and a multilayer coating deposited on the fibers.

Abstract: In some examples, an article may include a substrate and a coating on the substrate. In accordance with some of these examples, the coating may include a bond layer and an overlying layer comprising at least one oxide. In some examples, the bond layer comprises silicon metal and at least one of a transition metal carbide, a transition metal boride, or a transition metal nitride.

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 first set of layers and a second set of layers. At least one layer of the first set of layers is between two layers of the second set of layers. The at least one layer of the first set of layers comprises one of amorphous silica or silicon nitride, and the at least two layers of the second set of layers comprises the other of amorphous silica or silicon nitride.

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: A method of forming a composite article includes impregnating an inorganic fiber preform with a slurry composition. The slurry composition includes a particulate, a solvent, and a pre-gellant material. Gelling of the pre-gellant material in the slurry composition is initiated to immobilize the particulate and yield a gelled article, and substantially all solvent is removed from the gelled article to form a green composite article. The green composite article is then infiltrated with a molten infiltrant to form the composite article.

Abstract: A gas turbine engine is disclosed that includes a compressor, a combustor, and a turbine. The turbine includes a turbine shroud having a blade track formed from a ceramic matrix composite material. The combustor includes a combustor liner formed from one or more ceramic matrix composite tiles.

Abstract: In some examples, a technique may include positioning a first part comprising a ceramic or ceramic matrix composite and a second part comprising a ceramic or a CMC adjacent to each other to define a joint region at the interface of the first part and the second part. In some examples, the joint region may be heated using at least one of a laser or a plasma arc source to heat the joint region to an elevated temperature. The first and second parts may be pressed together and cooled to join the first and second parts at the joint region. In other examples, a solid braze material including a filler material and a metal or alloy may be delivered to the joint region and locally heated to cause a constituent of the filler material and a constituent of the metal or alloy to react. When reacted, the constituents may form a solid material, which may join the first and second parts.

Abstract: A turbine shroud for a turbine of a gas turbine engine is disclosed. The turbine shroud is configured to direct products of a combustion reaction in a combustor of the gas turbine engine toward a plurality of rotatable turbine blades of the turbine to cause the plurality of turbine blades to rotate.

Abstract: A barrier coating for isolating a metallic support component from a composite component in a gas turbine engine is provided. The barrier coating may be applied to the metallic support component so that when the ceramic component is mounted on the metallic support component the barrier coating is engaged.

Abstract: One aspect of the present disclosure includes a turbine vane assembly comprising a vane made from ceramic matrix composite material having an outer wall extending between a leading edge and a trailing edge and between a first end and an opposing second end; an endwall made at least partially from a ceramic matrix composite material configured to engage the first end of the vane; and a retaining region including corresponding bi-cast grooves formed adjacent the first end of the vane and a receiving aperture formed in the endwall; wherein a bond is formed in the retaining region to join the vane and endwall together.

Abstract: A turbine shroud for a gas turbine engine includes an annular metallic carrier, a blade track, and a cross-key connection formed between the annular metallic carrier and the ceramic blade track. The cross-key connection is formed between the annular metallic carrier and inserts included in the blade track. The inserts are bonded to an annular runner also included in the blade track by a braze layer.

Abstract: End mills are disclosed which may be made monolithically of ceramic or other materials. The cutting portions of the end mills have lengths of cut that are no more than twice their cutting diameters and cores which are at least 0.7 times their cutting diameters. Their axial blades have cutting edges with negative radial rake and are separated by helical flutes. Their cutting ends have negative axial rake and are gashed ahead of center and have radial cutting edges with negative rake. Such end mills also have radiused corners and gashes transitioning from radial to axial at a flute. Methods of milling materials using such ceramic end mills are also disclosed.

Abstract: End mills are disclosed which may be made monolithically of ceramic or other materials. The cutting portions of the end mills have lengths of cut that are no more than twice their cutting diameters and cores which are at least 0.7 times their cutting diameters. Their axial blades have cutting edges with negative radial rake and are separated by helical flutes. Their cutting ends have negative axial rake and are gashed ahead of center and have radial cutting edges with negative rake. Such end mills also have radiused corners and gashes transitioning from radial to axial at a flute. Methods of milling materials using such ceramic end mills are also disclosed.

Abstract: Additions of substitutional transition metal elements are made to improve the densifiability of titanium diboride while eliminating or minimizing the presence of deleterious grain boundary phases in the resultant bulk titanium diboride articles.

Abstract: Additions of substitutional transition metal elements are made to improve the densifiability of titanium diboride while eliminating or minimizing the presence of deleterious grain boundary phases in the resultant bulk titanium diboride articles.