Abstract: A ceramic matrix composite (CMC) structure (50) with first (26) and second (28) CMC walls joined at an intersection (34) containing continuous fibers (53). A gusset (52) is formed in the intersection by an inward bending of some or all ceramic fibers (53) of the intersection, resulting in a diagonal brace between the first and second CMC walls. This creates a depression (54) or void (59) in the intersection. One or more ceramic reinforcement devices fill or span the depression to prevent distortion of the gusset. The reinforcement devices may include a ceramic filler (60) or core (61), a CMC rod or cord (56), and a CMC tape (62). The ceramic filler (60) may be continuous with a ceramic insulation layer (36) on an outer surface of the first CMC wall.

Abstract: A cooling channel (36, 36B) cools an exterior surface (40 or 42) or two opposed exterior surfaces (40 and 42). The channel has a near-wall inner surface (48, 50) with a width (W1). Interior side surfaces (52, 54) may converge to a reduced channel width (W2). The near-wall inner surface (48, 50) may have fins (44) aligned with a coolant flow (22). The fins may highest at mid-width of the near-wall inner surface. A two-sided cooling channel (36) may have two near-wall inner surfaces (48, 50) parallel to two respective exterior surfaces (40, 42), and may have an hourglass shaped transverse sectional profile. The tapered channel width (W1, W2) and the fin height profile (56A, 56B) increases cooling flow (22) into the corners (C) of the channel for more uniform and efficient cooling.

Abstract: A sealing arrangement for use in a turbine engine having ceramic components. The sealing arrangement is retained in a seal gap formed between adjacent segments and is compliant to accommodate variations in the size of the seal gap as the adjacent segments move relative to one another.

Abstract: A gas turbine airfoil (20) having a load-bearing core (30). A honeycomb structure (40A, 42A) is attached to pressure and/or suction sides (22, 24) of the core and is filled with ceramic insulation (50). A ceramic matrix composite boot (60A, 60B, 60C) may cover the leading edge (26) of the core. Edges (61, 62) of the boot may be attached to the core by rows of pins (63A, 63B) or by flanges (65) inserted in slots (69) in the core. The pins may be formed in place by forming pin holes (64) in the boot, clamping the boot onto the core, filling the pin holes with metal or ceramic and metal particles, and heating the particles for internal cohesion and solid-state diffusion bonding (66) with the core. The boot may have a central portion (71) that is not bonded to the core to allow differential thermal expansion.

Abstract: A method of processing solid core ceramic matrix composite articles. The method improves the physical characteristics of the article by forming the airfoil using a co-processing method wherein a refractory ceramic is cast against a preformed ceramic matrix composite (CMC) shell. In one aspect, the shell is continuous to help prevent delaminations. In another aspect, the shell is open. In one embodiment, the article includes a split line. The split line helps the article to be less susceptible to damage caused from internal strain.

Abstract: A stack of substantially parallel ceramic plates (22) separated and interconnected by ceramic spacers (26, 27) forming a seal structure (20) with a length (L), a width (W), and a thickness (T). The spacers are narrower in width than the plates, and may be laterally offset from spacers in adjacent rows to form a space (28) in a row that aligns with a spacer in another adjacent row. An adjacent plate bends into the space when the seal structure is compressed in thickness. The spacers may have gaps (60, 62) forming a stepped or labyrinthine cooling flow path (66) within the seal structure. The spacers of each row may vary in lateral separation, thus providing a range of compressibility that varies along the width of the seal structure.

Abstract: A gas turbine ring segment (10) for use in gas turbine engines made from a ceramic matrix composite (CMC) material is disclosed. The ring segment includes a stacked multiplicity of CMC thin-sheet lamellae (25a, 25b) each comprising a peripheral surface collectively defining a cross-section profile of the ring segment. The lamellae collectively define a channel (11) formed in the center thereof for receiving a bow-tie member (27). The bow-tie member is disposed in the channel for holding together the stacked lamellae in a through thickness direction, and the in-plane strength of the bow-tie member is perpendicular to the in-plane strength of the lamellae. A stem portion (33) of the assembly may be further secured with a wrap (38) of CMC ribbon.

Abstract: A gas turbine blade (10) including a hollow mid-span snubber (16). The snubber is affixed to the airfoil portion (14) of the blade by a fastener (20) passing through an opening (24) cast into the surface (22) of the blade. The opening is defined during an investment casting process by a ceramic pedestal (38) which is positioned between a ceramic core (32) and a surrounding ceramic casting shell (48). The pedestal provides mechanical support for the ceramic core during both wax and molten metal injection steps of the investment casting process.

Abstract: A method of making a combustion turbine component includes forming a metallic body by direct metal fabrication (DMF) to have at least one surface portion defining a first plurality of surface cooling features each having a first dimension and at least one second surface cooling feature on at least one of the first plurality of surface cooling features and having a second dimension less than said first dimension and less than 200 ?m. Forming the metallic body by DMF may include forming a plurality of metallic combustion turbine subcomponent greenbodies by DMF and assembling the plurality of metallic combustion turbine subcomponent greenbodies together to form a metallic greenbody assembly. The metallic greenbody assembly may be sintered to thereby form the metallic body.

Abstract: A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

Abstract: A method of casting a component (42) having convoluted interior passageways (44). A desired three dimensional structure corresponding to a later-formed metal alloy component is formed by stacking a plurality of sheets (18, 20) of a fugitive material. The sheets contain void areas (22) corresponding to a desired interior passageway in the metal alloy component. A ceramic slurry material is cast into the three dimensional structure to form either a ceramic core (34) or a complete ceramic casting vessel (38). If just a ceramic core is formed, a wax pattern is formed around the ceramic core and an exterior ceramic shell (38) is formed around the wax pattern by a dipping process prior to the removal of the fugitive material and wax. An alloy component having the desired interior passageway is cast into the casting vessel after the fugitive material is removed.

Abstract: A wall structure (32, 42, 68, 70, 80) with layers (A, B, C, D, E) of non-random voids (26A, 26B, 28B, 30B) that interconnect to form discretely defined tortuous passages between an interior (21) and an exterior surface (23) of the wall for transpiration cooling of the wall. A coolant flow (38) through the wall may be metered by restrictions in coolant outlets (31) and/or within the passages to minimize the coolant requirement. Pockets (44) may be formed on the exterior surface of the wall for thermal Insulation (46). The layers may be formed by lamination, additive manufacturing, or casting. Layer geometries include alternating layers (A, B, C) with different overlapping void patterns (42), 3-D lattice structures (70), and offset waffle structures (80).

Abstract: A turbine engine component, such as a turbine blade or vane, with complex internal features can be cast using a core having a first region with normal resolution features and a second region with high resolution features. The core can be formed from a single structure. Alternatively, the first region can be defined by a first ceramic core piece, which can be formed by any conventional process, such as by injection molding or transfer molding. The second region can be defined by a second ceramic core piece formed separately by a method effective to produce high resolution features, such as tomo lithographic molding. The first core piece and the second core piece can be joined by interlocking engagement, such as by male and female dovetails. The high resolution features can be effective to produce high efficiency internal cooling features in the cast component.

Abstract: A method of manufacturing a component, including providing a three-dimensional computer model of the component to be produced; deconstructing the three-dimensional computer model by defining a plurality of model slices; forming a plurality of metallic foils, where each foil corresponds to a specific model slice; assembling the plurality of formed foils in a tool to form a three-dimensional component stack; and bonding the three-dimensional component stack to form the component. Characteristics of the foils may differ in various portions of the stack, such as being a different material, having a different thickness, or having a different grain orientation. The control of dimensional tolerances of internal structures, such as cooling passages, in three dimensions is devolved into two separate steps of 1) selecting a thickness of each slice/foil, and 2) controlling in two dimensions a material removal process applied to the respective foil.

Abstract: An investment casting process wherein the wax pattern tool (44) is flexible to facilitate removal of the tool from the cast wax pattern (52) even when the cast shape would otherwise require multiple pull planes. The flexible tool may include a flexible insert (42) precisely indexed to a surrounding coffin mold (40), and thereby to an enclosed ceramic core (10). Positioning pins (106) may extend from the flexible tool to make compliant contact against the core prior to a wax injection step. The surface of the resulting wax pattern may contain an engineered topography (36) replicated through the flexible surface from a master tool (12). The flexible tool may encase thermally conductive or magnetic particles (92), or other active device (96) such as a sensor or vibrator which is operable during wax injection.

Abstract: Alloy products are produced with a waxless casting process. A model of a ceramic casting vessel (34) defining a desired product shape is digitally divided into sections (10, 40, 42). Each section is translated into a soft alloy mater tool (14) including precision inserts (20) where needed for fine detail. A flexible mold (24) is cast from each master tool, and a section of the ceramic casting vessel is cast from the respective flexible mold. The vessel sections are assembled by aligning cooperating precision features (58, 60) cast directly into each section and the alloy part is cast therein. No wax or wax pattern tooling is needed to produce the cast alloy product. Engineered surface features (54) may be included on both the interior and exterior surfaces of the shell sections.

Abstract: An investment casting process for a hollow component such as a gas turbine blade utilizing a ceramic core (10) that is cast in a flexible mold (24) using a low pressure, vibration assisted casting process. The flexible mold is cast from a master tool (14) machined from soft metal using a relatively low precision machining process, with relatively higher precision surfaces being defined by a precision formed insert (22) incorporated into the master tool. A plurality of identical flexible molds may be formed from a single master tool in order to permit the production of ceramic cores at a desired rate with a desired degree of part-to-part precision.

Abstract: A method of making a combustion turbine component includes forming a metallic body by direct metal fabrication (DMF) to have at least one surface portion defining a first plurality of surface cooling features each having a first dimension and at least one second surface cooling feature on at least one of the first plurality of surface cooling features and having a second dimension less than said first dimension and less than 200 ?m. Forming the metallic body by DMF may include forming a plurality of metallic combustion turbine subcomponent greenbodies by DMF and assembling the plurality of metallic combustion turbine subcomponent greenbodies together to form a metallic greenbody assembly. The metallic greenbody assembly may be sintered to thereby form the metallic body.

Abstract: A sealing arrangement for use in a turbine engine having ceramic components. The sealing arrangement is retained in a seal gap formed between adjacent segments and is compliant to accommodate variations in the size of the seal gap as the adjacent segments move relative to one another.

Abstract: A ceramic matrix composite (CMC) structure 12 includes a plurality of layers (e.g., 16, 18, 20) of ceramic fibers. The CMC structure 12 further includes a plurality of spaced apart objects 22 on at least some of the plurality of layers along a thickness of the composite structure. The inclusion of the objects introduces an out-of-plane fiber displacement arranged to increase an interlaminar shear strength of the structure.