Abstract: A green body ceramic matrix composite material (30) is formed using ceramic fibers (32) in an intermediate state disposed in a green body ceramic matrix material (34). The fibers may be in either a dry but unfired (green) condition or in a partially fired condition. Selective control of the degree of pre-firing (pre-shrinkage) of the fibers may be used to control the level of residual stresses within the resulting refractory material resulting from differential shrinkage of the fibers and the matrix material during processing of the composite material.

Abstract: A material system (60) contains close packed hollow shapes (50, 70) having a dense wall structure (52, 66), which are bonded together and which may contain a matrix binder material (56) between the shapes, where the system has a stable porosity, and is abradable and thermally stable at temperatures up to possibly 1700° C., where such systems are useful in turbine apparatus.

Abstract: A method of manufacturing a composite structure uses a layer of an insulating material (22) as a mold for forming a substrate of a ceramic matrix composite (CMC) material (24). The insulating material may be formed in the shape of a cylinder (10) with the CMC material wound on an outer surface (14) of the cylinder to form a gas turbine combustor liner (20). Alternatively, the insulating material may be formed in the shape of an airfoil section (32) with the CMC material formed on an inside surface (36) of the insulating material. The airfoil section may be formed of a plurality of halves (42, 44) to facilitate the lay-up of the CMC material onto an easily accessible surface, with the halves then joined together to form the complete composite airfoil. In another embodiment, a box structure (102) defining a hot gas flow passage (98) is manufactured by forming insulating material in the shape of opposed airfoil halves (104) joined at respective opposed ends by platform members (109).

Abstract: A composite structure (62) having a bond enhancement member (76) extending across a bond joint (86) between a ceramic matrix composite (CMC) material (80) and a ceramic insulation material (82), and a method of fabricating such a structure. The bond enhancement member may extend completely through the CMC material to be partially embedded in a core material (84) bonded to the CMC material on an opposed side from the insulation material. A mold (26) formed of a fugitive material having particles (18) of a bond enhancement material may be used to form the CMC material. A two-piece mold (38, 46) may be used to drive a bond enhancement member partially into the CMC material. A compressible material (56) containing the bond enhancement member may be compressed between a hard tool (60) and the CMC material to drive a bond enhancement member partially into the CMC material.

Abstract: A method for making a material system includes the steps of: providing a chamber, placing hollow geometric shapes in the chamber, closing the chamber, evacuating air from the chamber, feeding a binder for the shapes into the evacuated chamber to impregnate the geometric shapes, drying the binder permeated geometric shapes, and heating the hollow shapes and binder to provide a unitary, sintered material system.

Abstract: An alumina comprising composition protective overlayer (20) for protecting a ceramic matrix composite material (12) from a high temperature, moisture-containing environment. Alumina may be used as a protective overlayer to protect an underlying mullite layer to temperatures in excess of 1,500° C. The coating may have porosity of greater than 15% for improved thermal shock protection. To prevent the ingress of oxygen to an underlying ceramic material, an oxide barrier layer may be optionally disposed between the alumina coating and the ceramic material. Such a protective overlayer may be used for an article having a ceramic oxide or non-oxide substrate.

Abstract: A method for making a thermal insulating material includes the steps of: providing a chamber, placing hollow geometric shapes in the chamber, closing the chamber, evacuating air from the chamber, feeding a slurry into an adjacent slurry chamber, pressurizing the slurry chamber and forcing the slurry in to the sphere chamber around the spheres against a fibrous material adjacent a side wall of the sphere chamber. The fibrous material allows capillary wicking of the liquid from the slurry around the spheres. Due to this pressure the spheres and slurry are semi dried into a green state. The material in its green state green is subsequently dried and fired to form the insulating material.

Abstract: A material system (60) contains close packed hollow shapes (50, 70) having a dense wall structure (52, 66), which are bonded together and which may contain a matrix binder material (56) between the shapes, where the system has a stable porosity, and is abradable and thermally stable at temperatures up to possibly 1700° C., where such systems are useful in turbine apparatus.

Abstract: A hybrid vane (50) for a gas turbine engine having a ceramic matrix composite (CMC) airfoil member (52) bonded to a substantially solid core member (54). The airfoil member and core member are cooled by a cooling fluid (58) passing through cooling passages (56) formed in the core member. The airfoil member is cooled by conductive heat transfer through the bond ((70) between the core member and the airfoil member and by convective heat transfer at the surface directly exposed to the cooling fluid. A layer of insulation (72) bonded to the external surface of the airfoil member provides both the desired outer aerodynamic contour and reduces the amount of cooling fluid required to maintain the structural integrity of the airfoil member. Each member of the hybrid vane is formulated to have a coefficient of thermal expansion and elastic modulus that will minimize thermal stress during fabrication and during turbine engine operation.

Abstract: An alumina comprising composition protective overlayer (20) for protecting a ceramic matrix composite material (12) from a high temperature, moisture-containing environment. Alumina may be used as a protective overlayer to protect an underlying mullite layer to temperatures in excess of 1,500° C. The coating may have porosity of greater than 15% for improved thermal shock protection. To prevent the ingress of oxygen to an underlying ceramic material, an oxide barrier layer may be optionally disposed between the alumina coating and the ceramic material. Such a protective overlayer may be used for an article having a ceramic oxide or non-oxide substrate.

Abstract: A hybrid vane (50) for a gas turbine engine having a ceramic matrix composite (CMC) airfoil member (52) bonded to a substantially solid core member (54). The airfoil member and core member are cooled by a cooling fluid (58) passing through cooling passages (56) formed in the core member. The airfoil member is cooled by conductive heat transfer through the bond ((70) between the core member and the airfoil member and by convective heat transfer at the surface directly exposed to the cooling fluid. A layer of insulation (72) bonded to the external surface of the airfoil member provides both the desired outer aerodynamic contour and reduces the amount of cooling fluid required to maintain the structural integrity of the airfoil member. Each member of the hybrid vane is formulated to have a coefficient of thermal expansion and elastic modulus that will minimize thermal stress during fabrication and during turbine engine operation.

Abstract: A material system (60) contains close packed hollow shapes (50, 70) having a dense wall structure (52, 66), which are bonded together and which may contain a matrix binder material (56) between the shapes, where the system has a stable porosity, and is abradable and thermally stable at temperatures up to possibly 1700° C., where such systems are useful in turbine apparatus.

Abstract: A ceramic matrix composite material (10) having a plurality of interlaminar stitches (16) as shown in FIG. 1. The stitches are formed by directing laser energy into the material to melt and recast zones of the material in a direction transverse to the layers of reinforcing fibers(12). The stitches not only improve the interlaminar strength of the material, but they also increase the through-thickness thermal conductivity of the material, thereby reducing thermal-induced stresses. The zones of recast material (18) may define holes (20) extending at least partially through the thickness of the material. The holes may be filled with a filler material (24), thereby mitigating any adverse loss-of-area effect created by the holes.

Abstract: A method for making a thermal insulating material includes the steps of: providing a chamber, placing hollow geometric shapes in the chamber, closing the chamber, evacuating air from the chamber, feeding a slurry into an adjacent slurry chamber, pressurizing the slurry chamber and forcing the slurry in to the sphere chamber around the spheres against a fibrous material adjacent a side wall of the sphere chamber. The fibrous material allows capillary wicking of the liquid from the slurry around the spheres. Due to this pressure the spheres and slurry are semi dried into a green state. The material in its green state green is subsequently dried and fired to form the insulating material.

Abstract: A ceramic matrix composite material (10) having a plurality of interlaminar stitches (16) as shown in FIG. 1. The stitches are formed by directing laser energy into the material to melt and recast zones of the material in a direction transverse to the layers of reinforcing fibers(12). The stitches not only improve the interlaminar strength of the material, but they also increase the through-thickness thermal conductivity of the material, thereby reducing thermal-induced stresses. The zones of recast material (18) may define holes (20) extending at least partially through the thickness of the material. The holes may be filled with a filler material (24), thereby mitigating any adverse loss-of-area effect created by the holes.

Abstract: A ceramic composition for insulating components, made of ceramic matrix composites, of gas turbines is provided. The composition comprises a plurality of hollow oxide-based spheres of various dimensions, a phosphate binder, and at least one oxide filler powder, whereby the phosphate binder partially fills gaps between the spheres and the filler powders. The spheres are situated in the phosphate binder and the filler powders such that each sphere is in contact with at least one other sphere and the arrangement of spheres is such that the composition is dimensionally stable and chemically stable at a temperature of approximately 1600° C. A stationary vane of a gas turbine comprising the composition of the present invention bonded to the outer surface of the vane is provided. A combustor comprising the composition bonded to the inner surface of the combustor is provided. A transition duct comprising the insulating coating bonded to the inner surface of the transition is provided.