摘要:
An airfoil (44) formed of a plurality of pre-fired structural CMC panels (46, 48, 50, 52). Each panel is formed to have an open shape having opposed ends (54) that are free to move during the drying, curing and/or firing of the CMC material in order to minimize interlaminar stresses caused by anisotropic sintering shrinkage. The panels are at least partially pre-shrunk prior to being joined together to form the desired structure, such as an airfoil (42) for a gas turbine engine. The panels may be joined together using a backing member (30), using flanged ends (54) and a clamp (56), and/or with a bond material (36), for example.
摘要:
Embodiments of the invention relate to various cooling systems for a turbine vane made of stacked ceramic matrix composite (CMC) laminates. Each airfoil-shaped laminate has an in-plane direction and a through thickness direction substantially normal to the in-plane direction. The laminates have anisotropic strength characteristics in which the in-plane tensile strength is substantially greater than the through thickness tensile strength. Such a vane construction lends itself to the inclusion of various cooling features in individual laminates using conventional manufacturing and forming techniques. When assembled in a radial stack, the cooling features in the individual laminates can cooperate to form intricate three dimensional cooling systems in the vane.
摘要:
A method of manufacturing a hybrid structure (100) having a layer of CMC material (28) defining an interior passageway (24) and a layer of ceramic insulating material (18) lining the passageway. The method includes the step of casting the insulating material to a first thickness required for effective casting but in excess of a desired second thickness for use of the hybrid structure. An inner mold (14) defining a net shape desired for the passageway remains in place after the casting step to mechanically support the insulating material during a machining process used to reduce the thickness of the insulating material from the as-cast first thickness to the desired second thickness. The inner mold also provides support as the CMC material is deposited onto the insulating material. The inner mold may include a fugitive material portion (20) to facilitate its removal after the CMC material is formed.
摘要:
A stacked laminate component for a turbine engine that may be used as a replacement for one or more metal components is provided. The stacked laminate component can have a body formed by a process of stacking and laminating layers to define a radially inner surface along the hot gas path. The layers can be substantially orthogonal to the radially inner surface. The layers can be at least a first layer of a first material and a second layer of a second material. At least the first material is a ceramic matrix composite. The second material can have a higher thermal conductivity or a higher creep strength than the first material.
摘要:
Embodiments of the invention relate to a robust turbine vane made of stacked airfoil-shaped CMC laminates. Each laminate has an in-plane direction and a through thickness direction substantially normal to the in-plane direction. The laminates have anisotropic strength characteristics in which the in-plane tensile strength is substantially greater than the through thickness tensile strength. Thus, the laminates can provide strength in the direction of high thermal gradients and, thus, withstand the associated high thermal stresses. The laminates are relatively weak in through thickness (interlaminar) tension, but, in operation, relatively low through thickness tensile stresses can be expected. The laminates can be strong in through thickness compression; accordingly, the laminate stack can be held in through thickness compression by one or more fasteners. The CMC material can permit the inclusion of additional features such as cooling passages, ribs, spars, and thermal coatings, without compromising the strength characteristics of the material.
摘要:
A method to form an improved hybrid ceramic matrix composite structure comprises providing a ceramic matrix composite (CMC) with open features at a surface and applying a thermal barrier coating to the surface. The thermal barrier coating is preferably a friable graded insulation coating (FGI) having hollow ceramic spheres. For acceptance of a FGI coating the open features have a center-to-center separation distance in one or more directions that is between about 100 and about 1,000 percent of the diameter of the hollow ceramic spheres in the FGI and a depth that is between about 20 percent and about 200 percent of the diameter of the hollow ceramic spheres in the FGI. The open feature can result from the winding of tows about a mandrel; the lay-up of fabric including a surface fabric having an open weave; or the use of a 3-D weave, or a 3-D braid.
摘要:
A hybrid structure (50) and method of manufacturing the same including a structural ceramic matrix composite (CMC) material (42) coated with a layer of ceramic insulating tiles (24). Individual ceramic tiles are attached to a surface (22) of a mold (20). The exterior surface (32) of the tiles may be subjected to a mechanical process such as machining with the mold in place to provide mechanical support for the tiles. A layer of CMC material is then applied to bond the tiles and the CMC material together into a hybrid structure. The mold may include a fugitive material portion (26) to facilitate removal of the mold when the hybrid structure has a complex shape. Tiles located in different regions of the structure may have different compositions and/or dimensions. The gaps between adjacent tiles may be filled from the outside before the CMC material is applied or from the inside after the mold is removed.
摘要:
A stacked laminate component for a turbine engine that may be used as a replacement for one or more metal components is provided. The stacked laminate component can have a body formed by a process of stacking and laminating layers to define a radially inner surface along the hot gas path. The layers can be substantially orthogonal to the radially inner surface. The layers can be at least a first layer of a first material and a second layer of a second material. At least the first material is a ceramic matrix composite. The second material can have a higher thermal conductivity or a higher creep strength than the first material.
摘要:
A stacked ceramic matrix composite lamellate assembly (10) including shear force bearing structures (48) for resisting relative sliding movement between adjacent lamellae. The shear force bearing structures may take the form of a cross-lamellar stitch (50), a shear pin (62), a warp (90) in the lamellae, a tongue (104) and groove (98) structure, or an inter-lamellar sealing member (112), in various embodiments. Each shear force bearing structure secures a subset of the lamellae, with at least one lamella being common between adjacent subsets in order to secure the entire assembly.
摘要:
Thermally insulating layer incorporating a distinguishing agent and method for inspecting the insulating layer are provided. The distinguishing agent may be used for determining a remaining thickness of the thermally insulating layer.