Abstract: A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

Abstract: A cooling scheme for a blade outer air seal includes a perimeter cooling arrangement configured to convectively cool a perimeter of the blade outer air seal, and a core cooling arrangement configured to cool a central portion of the blade outer air seal through impingement cooling and to provide film cooling to an inner diameter face of the blade outer air seal.

Abstract: A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

Abstract: A cooling scheme for a blade outer air seal includes a perimeter cooling arrangement configured to convectively cool a perimeter of the blade outer air seal, and a core cooling arrangement configured to cool a central portion of the blade outer air seal through impingement cooling and to provide film cooling to an inner diameter face of the blade outer air seal.

Abstract: A cooling scheme for a blade outer air seal includes a perimeter cooling arrangement configured to convectively cool a perimeter of the blade outer air seal, and a core cooling arrangement configured to cool a central portion of the blade outer air seal through impingement cooling and to provide film cooling to an inner diameter face of the blade outer air seal.

Abstract: A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

Abstract: A composite article includes a substrate and a thermal barrier secured to the substrate. The thermal barrier includes a plurality of closed pores within a ceramic matrix. For example, the closed pores comprise 20 vol % to 80 vol % of the thermal barrier.

Abstract: A cooling scheme for a blade outer air seal includes a perimeter cooling arrangement configured to convectively cool a perimeter of the blade outer air seal, and a core cooling arrangement configured to cool a central portion of the blade outer air seal through impingement cooling and to provide film cooling to an inner diameter face of the blade outer air seal.

Abstract: The tip portion of a blade of a gas turbine is repaired in-situ in the gas turbine without removing the blade from the turbine rotor disk. To facilitate the in-situ repair of the tip portion of the turbine blades, one or more access holes may be provided in the turbine shroud or blade outer air seal circumscribing the plurality of turbine blades extending radially outward from the turbine rotor dick.

Abstract: A blade outer air seal system includes a body that extends between two circumferential sides, a leading edge and a trailing edge, and a radially inner side and a radially outer side. An attachment section associated with the body and includes at least one engagement surface that is transverse to the radially outer side.

Abstract: A seal assembly has a first seal member, a second seal member, and a third seal member. The first seal member has a wear surface that contacts a first wall of the cavity at two sealing locations. The second seal member has a wear surface that contacts a second wall of the cavity at two sealing locations. The third seal member extends between and resiliently connects the first seal member to the second seal member.

Abstract: A hybrid sacrificial core for forming an impingement space and an internal cooling passageway network separate from the impingement space of a part may comprise a ceramic core having a first surface portion for forming the impingement space, and a refractory metal core that forms a plurality of passages of the internal cooling passageway network.

Abstract: An article of manufacture has a body formed in part of a first metal alloy and in part of a second metal alloy, the second metal alloy having a thermal coefficient of expansion that is less than the thermal coefficient of expansion of the first metal alloy. A BOAS segment for a gas turbine engine is disclosed wherein the formation of cracks due to thermal mechanical fatigue in the body of the disclosed BOAS segment is minimized, if not eliminated, through a unique construction of the disclosed BOAS segment, whether original equipment manufacture or a repaired blade outer air seal. A method for manufacture of a BOAS segment and a method for modifying a BOAS segment are disclosed.

Abstract: A blade outer air seal for a gas turbine engine is provided. The blade outer air seal includes a body having an outer radial surface, an inner radial surface, and a plurality of cooling air apertures. The body extends between a forward edge and an aft edge. The inner radial surface includes at least one first seal section, at least one second seal section, and a riser extending radially between the first seal section and the second seal section. Each of the plurality of cooling air apertures extends between the outer radial surface and the riser, and each cooling air aperture has an exit configured to direct cooling air substantially parallel to the second seal section of the inner radial surface.

Abstract: Gas turbine engines and related systems involving blade outer air seals are provided. In this regard, a representative blade outer air seal segment for a set of rotatable blades includes: a blade arrival end; and a blade departure end; each of the blade arrival end and the blade departure end being angularly offset with respect to a longitudinal axis about which the blades rotate.

Abstract: Gas turbine engines and related systems involving blade outer air seals are provided. In this regard, a representative blade outer air seal segment for a set of rotatable blades includes: a blade arrival end; and a blade departure end; each of the blade arrival end and the blade departure end being angularly offset with respect to a longitudinal axis about which the blades rotate.

Abstract: A gas turbine article includes a substrate, a plurality of geometric surface features that protrude from the substrate, and a thermally insulating topcoat disposed over the plurality of geometric surface features. The thermally insulating topcoat includes segmented portions that are separated by faults that extend through the topcoat from the geometric surface features.

Abstract: A turbine blade outer air seal segment assembly has a first turbine blade outer air seal segment with a first end portion, a middle portion and a second end portion. The first turbine blade outer air seal segment is for connection with a second turbine blade outer air seal segment to form at least a part of a shroud of a turbine rotor. A first cooling passage is disposed within the first turbine blade outer air seal segment. The cooling passage extends from the first end portion to the second end portion and a land is disposed in at least one of the first or second end portions. The land represents a portion for receiving a mold ejection pin for a core forming the cooling passage.

Abstract: A seal assembly has a first seal member, a second seal member, and a third seal member. The first seal member has a wear surface that contacts a first wall of the cavity at two sealing locations. The second seal member has a wear surface that contacts a second wall of the cavity at two sealing locations. The third seal member extends between and resiliently connects the first seal member to the second seal member.

Abstract: A weld set-up and weld process are provided that alleviate micro-cracking as between a pair of welded pieces. The weld set-up is provided in which the weld pieces are configured to cause micro-cracking to occur in a portion of the welded pieces that is then removed by post-processing machining techniques. This weld set-up includes a primary weld piece and a secondary weld piece with a flange portion that extends over the primary weld piece. When used in conjunction with electron beam welding, application of the weld beam onto the secondary weld piece causes the formation of a preferential nailhead that is formed exclusively in the first weld piece.