摘要:
A hybrid ceramic structure (10), for use in high temperature environments such as in gas turbines, is made from an insulating layer (12) of porous ceramic that is thermally stable at temperatures up to 1700° C. bonded to a high mechanical strength structural layer (8) of denser ceramic that is thermally stable at temperatures up to 1200° C., where optional high temperature resistant adhesive (9) can bond the layers together, where optional cooling ducts (11) can be present in the structural layer and where hot gas (14) can contact the insulating layer (12) and cold gas (15) can contact the structural layer (8).
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 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 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:
An article comprising a ceramic material having a ceramic matrix composite backing adapted for use in a gas turbine engine is provided. The article comprises a structural ceramic material having a hot side facing toward a high temperature environment and a cold side facing away from the high temperature environment; and a ceramic matrix composite composition having a strength greater than the strength of the ceramic material attached to the back of the cold side of the ceramic material, whereby crack initiation and propagation are inhibited by the ceramic matrix composition to a greater degree than by the ceramic material.
摘要:
The present invention is directed to a process for preparing a body of polycrystalline silicon doped with aluminum comprising melting a mixture of silicon powder and aluminum powder, rapidly quenching the melt, grinding the solidified silicon-aluminum alloy and hot pressing to form a compact.
摘要:
A method of repairing gas turbine engine components is provided. The method includes removing the damaged portion and fabricating an insert to match the removed portion. The insert is precision machined and crystallographically matched to the original component, and then bonded to this component using transient liquid phase bonding techniques and suitable heat treatment.
摘要:
A visual observation system for monitoring a welding operation being performed in a welding region by a welding torch, the torch having a longitudinal axis and including a housing. The system is composed of a closed light conducting channel supported by the torch and having a first end directed toward the welding region and a second end remote from the first end, and image generating device disposed at the second end of the channel for receiving light entering the channel via the first end in order to generate an image of the scene in front of the first end, a transpatent plate disposed in, and blocking, the light conducting channel for protecting the image generating device against soiling by particles produced by the welding operation, and elements for producing a flow of inert gas past the side of the transparent plate directed toward the first end for opposing the deposition of such particles on the plate. The a light conducting channel is dimensioned such that in at least one direction transverse to the longitudinal axis of the torch, the channel does not project beyond the torch housing.
摘要:
This is a process of fabricating directionally solidified turbine blades for combustion turbines. It is an improvement to the type of process where a mold containing molten metal is cooled in a controlled fashion such that solidification occurs slow enough to allow directional solidification beginning at the airfoil end. In the improved process solidification is monitored and magnetic mixing of the remaining molten metal is started at approximately the beginning of solidification of said root section and the rate of cooling of said blade is increased to a rate faster than at which directional solidification occurs. A blade is produced with a directionally solidified airfoil section and a fine grained root section and without a substantially inhomogeneous portion at the interface between the airfoil and root sections.
摘要:
A method of bonding cast superalloys is disclosed. The method includes the steps of casting separate superalloy component parts, machining the mating surfaces of the separate parts in a controlled manner to avoid recrystallization of the material and to ensure a tight fit between the parts, bonding the parts together, and thermally treating the bonded component. In a preferred embodiment, the component is a turbine blade for a land-based gas turbine.