摘要:
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.
摘要:
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.
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 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.
摘要:
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.
摘要:
Structural arrangements and methodology are provided for strengthening a bond between corresponding surfaces of a thermally insulating ceramic coating (14) and a ceramic matrix composite substrate (12). A subsurface inclusion of spheroid objects allows to influence a texture of an outer surface of the CMC substrate to enhance the bonding characteristics between the corresponding surfaces.
摘要:
A ceramic matrix composite (CMC) structure and methods of fabricating such structure are disclosed. In one example, the surface of a CMC substrate (12) is urged against a surface of a tool having blunt teeth. The blunt teeth can form surface indents that can serve as a first bond-enhancing arrangement between the surface of the substrate and a corresponding boundary of a thermally-insulating coating (14). In another example, sharp teeth can form surface indents and also penetrate through the surface of the substrate to cut some of the fibers beneath the surface of the substrate into split fiber segments, and a portion of the split fiber segments can protrude above the surface of the substrate. The protruding fiber segments can serve as a second bond-enhancing arrangement between the surface of the substrate and the corresponding boundary of the coating.
摘要:
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.
摘要:
An insulating material 14 adapted for use in a high temperature environment for coating a turbine component is provided. The insulating material comprises a plurality of geometric shapes 18. The insulating material further comprises a binder for binding together the geometric shapes. A plurality of discontinuous fibers is added to the binder. The discontinuous fibers are adapted to controllably affect one or more properties of the insulating material. For example, non-fugitive chopped fibers 50 may be added to affect a tensile strength property of the insulating material, and fugitive chopped fibers 52 may be added to affect a density property of the insulating material.
摘要:
A composite material (10) formed of a ceramic matrix composite (CMC) material (12) protected by a ceramic insulating material (14). The constituent parts of the insulating material are selected to avoid degradation of the CMC material when the two layers are co-processed. The CMC material is processed to a predetermined state of shrinkage before wet insulating material is applied against the CMC material. The two materials are then co-fired together, with the relative amount of shrinkage between the two materials during the firing step being affected by the amount of pre-shrinkage of the CMC material during the bisque firing step. The shrinkage of the two materials during the co-firing step may be matched to minimize shrinkage stresses, or a predetermined amount of prestress between the materials may be achieved. An aluminum hydroxyl chloride binder material (24) may be used in the insulating material in order to avoid degradation of the fabric (28) of the CMC material during the co-firing step.