A blade outer air seal for a gas turbine engine includes a seal arc-segment that defines a gaspath side, a non-gaspath side, leading and trailing ends, and first and second circumferential sides. A portion of the gaspath side has a geometrically segmented coating section. The geometrically segmented coating section includes a wall that has an array of cells, and a coating disposed in the array of cells.

A seal carrier for a turbomachine, in particular a gas turbine, including a carrier base and at least one seal member, the at least one seal member being connected to the carrier base, and the at least one seal member being formed by a plurality of cavities arranged adjacent one another, in particular in a regular fashion, in the circumferential direction and the axial direction, the cavities extending from the carrier base in the radial direction, is provided. At least one stiffening element on the carrier base, the stiffening element extending along the circumferential direction and at least partially covering the at least one seal member at one of its axial end regions is provided.

A blade outer air seal (BOAS) for a gas turbine engine includes, among other things, a seal body having a radially inner face and a radially outer face that axially extend between a leading edge portion and a trailing edge portion. The BOAS includes a trough disposed on the radially inner face and an abradable seal received within the trough. The trough is open to expose a leading edge of the abradable seal to a core flow path of the gas turbine engine.

A system and method for forming a ceramic matrix composite blade track is provided. The method may include stacking a plurality of first plies to form a first porous preform layer, the first plies including a plurality of first ceramic fibers. The method may further include stacking a plurality of second plies to form a second porous preform layer, the second plies including a plurality of second ceramic fibers. The method may further include combining the first porous preform layer and the second porous preform layer to form a unified porous preform. The method may further include forming a structural layer by infiltrating the first porous preform with a first ceramic matrix material, and forming an abradable layer by infiltrating the second porous preform with a second ceramic matrix material.

One aspect of the disclosure involves a nib material comprising a polymeric matrix and carbon nanotubes in the matrix. In one or more embodiments of any of the foregoing embodiments, the matrix comprises a silicone. In one or more embodiments of any of the foregoing embodiments, the rub material is at least 1.0 mm thick. In one or more embodiments of any of the foregoing embodiments, the silicone is selected from the group consisting of dimethyl- and fluoro-silicone rubbers and their copolymers. In one or more embodiments of any of the foregoing embodiments, the carbon nanotubes at least locally have a concentration of 1-20% by weight.

A rub material (124) comprises a polymeric matrix (128) and polymeric micro-balloons (130) in the matrix.

A coating system on a CMC substrate is provided, along with methods of its tape deposition onto a substrate. The coating system can include a bond coat on a surface of the CMC substrate; a first rare earth silicate coating on the bond coat; a first sacrificial coating of a first reinforced rare earth silicate matrix on the at least one rare earth silicate layer; a second rare earth silicate coating on the sacrificial coating; a second sacrificial coating of a second reinforced rare earth silicate matrix on the second rare earth silicate coating; a third rare earth silicate coating on the second sacrificial coating; and an outer layer on the third rare earth silicate coating. The first sacrificial coating and the second sacrificial coating have, independently, a thickness of about 4 mils to about 40 mils.

A method includes providing a ceramic matrix composite (CMC) seal arc segment that has radially inner and outer sides, attaching an abradable layer on the radially outer side of the CMC seal arc segment, providing a carrier to support the CMC seal arc segment, the carrier including a ridge, and sliding the CMC seal arc segment relative to the carrier such that during the sliding the ridge cuts a groove into the abradable layer, the ridge remaining disposed in the groove to thereby provide a labyrinth seal that partitions the cooling cavity between the carrier and the CMC seal arc segment into sub-cavities.

The present invention relates to a rotor blade shroud for a turbomachine, comprising a sealing tip and a support structure that abuts the sealing tip. The support structure has at least one intermediate region in which a structural segment is arranged, wherein the radially outwardly arranged surface of the support structure and of the structural segment forms an essentially planar surface. The present invention further relates to a rotor blade for a turbomachine, comprising a rotor blade shroud as well as two methods of manufacturing a rotor blade shroud and a method of manufacturing a rotor blade.

A gas turbine engine article includes a substrate that has at least one step, and the step includes an undercut. A thermally insulating topcoat is disposed on the substrate. The thermally insulating topcoat includes at least one fault that extends from the step.