摘要:
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).
摘要:
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.
摘要:
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.
摘要:
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).
摘要:
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.
摘要:
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.
摘要:
A multi-wall gas turbine airfoil (192) and method of forming same using a casting core (150) having a monolithic body configured to define a pressure side wall (12), a suction side wall (14), and a third wall (16). The casting core is formed around a fugitive insert (96) during a single pour casting process.
摘要:
A multi-wall gas turbine airfoil (192) and method of forming same using a casting core (150) having a monolithic body configured to define a pressure side wall (12), a suction side wall (14), and a third wall (16). The casting core is formed around a fugitive insert (96) during a single pour casting process.
摘要:
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.
摘要:
A method of forming a ceramic layer on a metal substrate. A substrate (40) is formed (54) from a powder (24) of the metal, and may optionally be partially sintered (56). A layer (43) of powdered ceramic is formed (58) on or applied against the substrate (45). The ceramic powder may include a proportion of nano-sized particles effective to reduce the ceramic sintering temperature and to increase the sintering shrinkage of the ceramic layer to more closely match that of the metal substrate. The substrate and layer are then co-sintered (21, 60) at a temperature and for a duration that densifies and bonds them, producing a metal/ceramic layered material system with low interface stress that is durable to temperature variations in a gas turbine. Spark plasma sintering (32, 34, 36) may be used to sinter and/or co-sinter substrate and layer materials that normally cannot be sintered.