Rolls-royce North American Technologies Inc.

Hyper-therm High-temperature Composites, Inc.

Other

Rolls-royce High Temperature Composites Inc.

Rolls-royce Corporation

Northrop Corporation

The Boeing Company

Hyper-thern High-temperature Composites, Inc.

Wayne S Steffier

Robert J Shinavski

Ted Joseph Freeman

David John Thomas

Adam Lee Chamberlain

Richard Christopher Uskert

Harry W Carpenter

James W Bohlen

Daniel Kent Vetters

Andrew Joseph Lazur

Stephen Isaiah Harris

Todd Engel

William E Rumberger

Michael Jacquinto

A method of making a fiber preform for ceramic matrix composite (CMC) fabrication that utilizes a fugitive binder and a machining step is described. The method includes, according to one embodiment, laying up a plurality of plies to form a stack, where each ply comprises an arrangement of fibers. The stack is infiltrated with a polymer at an elevated temperature to form an infiltrated stack that is cooled to form a rigid preform. The rigid fiber preform is machined to have a predetermined shape, such that a machined fiber preform is formed. A composite assembly including the machined fiber preform is formed and then the composite assembly is heated at a sufficient temperature to pyrolyze the polymer. Thus, a porous preform of a predetermined geometry is formed for further processing into a CMC.

Method of making a fiber preform for ceramic matrix composite (CMC) fabrication

A gas turbine engine composite vane assembly and method for making same are disclosed. The method includes providing at least two gas turbine engine airfoil composite preform components. The airfoil composite preform components are interlocked with a first locking component so that mating faces of the airfoil composite preform components face each other. A filler material is inserted between the mating surfaces of the airfoil composite preform components.

Gas turbine engine composite vane assembly and method for making the same

A combustor of a gas turbine engine and a turbine shroud for a turbine of a gas turbine engine are disclosed. The combustor is configured to ignite a mixture of compressed air and fuel in a combustion chamber included therein. The turbine shroud is configured to direct products of the combustion reaction toward a plurality of rotatable turbine blades of the turbine to cause the plurality of turbine blades to rotate.

Retention system for gas turbine engine assemblies

A gas turbine engine includes a turbine having turbine blades and a shroud having a blade track for positioning radially outside of the blades. At least one of the blades and the blade track are secured in place using a dovetail connection between a dovetail receiver and a dovetail assembly formed to include a contoured root.

Gas turbine engine with dovetail connection having contoured root

Gas turbine engine composite vane assembly and method for making same

A relatively low cost, lightweight and thermal stress-free mechanical fastener system having particular application for reliably joining together high temperature structural members (e.g., a pair of flat fiber-reinforced ceramic composite plates). The mechanical fastener system includes a ceramic composite fastener having a semi-circular head at one end to be countersunk in the structural members to be joined together and a dove tail retention feature formed in the shank or root at the opposite end. The composite fastener has a 2-dimensional (i.e., flat) profile that facilitates an economic manufacture thereof from densified ceramic composite material. A matched pair of thread forms having external threads and an internal dove tail relief to match the dove tail retention feature at the root of the composite fastener is held in face-to-face mating engagement with one another so as to establish a mechanical interlock around the root of the composite fastener. A 2-dimensional ceramic backing washer has a rectangular center hole dimensioned to receive the root of the composite fastener therethrough. A nut having internal threads that correspond to the external threads of the pair of thread forms is rotated into surrounding engagement with the thread forms to prevent a removal of the composite fastener and a separation of the structural members.

Mechanical fastener system for high-temperature structural assemblies

An actively-cooled, fiber-reinforced ceramic matrix composite thrust chamber for liquid rocket propulsion systems is designed and produced with internal cooling channels. The monocoque tubular structure consists of an inner wall, which is fully integrated to an outer wall via radial coupling webs. Segmented annular void spaces between the inner wall, outer wall and adjoining radial webs form the internal trapezoidal-shaped cooling channel passages of the tubular heat exchanger. The manufacturing method enables producing any general tubular shell geometry ranging from simple cylindrical heat exchanger tubes to complex converging-diverging, Delaval-type nozzle structures with an annular array of internal cooling channels. The manufacturing method allows for transitioning the tubular shell structure from a two-dimensional circular geometry to a three-dimensional rectangular geometry. The method offers the flexibility of producing internal cooling channels of either constant or continuously variable cross-sectional area, in addition to orienting the cooling channels either axially, helically or sinusoidally (e.g., undulating) with respect to the longitudinal axis of the tubular shell structure with without significant added manufacturing complication.

Actively-cooled fiber-reinforced ceramic matrix composite rocket propulsion thrust chamber and method of producing the same

A fiber-reinforced ceramic matrix composite material exhibiting increased matrix cracking strength and fracture toughness is produced by sequentially depositing a plurality of 5-500 nanometer-thick layers of a primary ceramic matrix material phase periodically separated by 1-100 nanometer-thick intermediate layers of a secondary matrix material phase onto the reinforcing fibers upon their consolidation. The resultant nanolayered matrix enhances the resistance to the onset of matrix cracking, thus increasing the useful design strength of the ceramic matrix composite material. The nanolayered microstructure of the matrix constituent also provides a unique resistance to matrix crack propagation. Through extensive inter-layer matrix fracture, debonding and slip, internal matrix microcracks are effectively diverted and/or blunted prior to their approach towards the reinforcing fiber, thus increasing the apparent toughness of the matrix constituent. This unique toughening mechanism serves to dampen energetic co-planar macrocrack propagation typically observed in conventionally manufactured ceramic matrix composites wherein matrix cracks are usually deflected at the fiber/matrix interphase region.

Fiber-reinforced ceramic composite material comprising a matrix with a nanolayered microstructure

A fiber-reinforced ceramic composite material exhibiting high tensile strength, high fracture toughness and high-temperature oxidation resistance is produced by simultaneously depositing a thin coating layer of refractory metal carbide with fugitive carbon onto the fiber reinforcement prior to the subsequent densification with the ceramic matrix. The energy behind propagating matrix cracks in the resulting composite material are effectively dissipated by crack deflection/branching, fiber debonding and frictional slip through the relatively weak and compliant fiber coating layer. These energy release and arrest mechanisms sufficiently impede the driving force behind unstable crack propagation and render the cracks non-critical, thereby serving to blunt and/or divert propagating matrix cracks at or around the reinforcing fiber. While significantly increasing the strength and fracture toughness of the composite, the compliant refractory fiber coating system enables the composite to remain oxidatively stable when stressed at or beyond the matrix cracking stress point and subsequently exposed to temperatures above 800.degree. C. in air,

Pseudo-porous fiber coating for toughened ceramic composite materials

A fiber-reinforced ceramic-matrix composite material exhibiting high tensile strength, high fracture toughness and high-temperature oxidation resistance is produced by alternatively depositing multiple thin layers of ceramic material separated by very thin intermediate layers of fugitive carbon onto the fiber reinforcement prior to the subsequent densification with the ceramic matrix. The energy behind propagating matrix cracks in the resulting composite material are effectively dissipated by the progressive increase in crack deflection/branching and frictional slip through the successive ceramic layers of the multilayer fiber coating system. These energy release and arrest mechanisms sufficiently impede the driving force behind unstable crack propagation and render the cracks non-critical, thereby serving to blunt and/or divert propagating matrix cracks at or around the reinforcing fiber. While significantly increasing the strength and fracture toughness of the composite, the multilayer refractory fiber coating system enables the composite to remain oxidatively stable when stressed at or beyond the matrix cracking stress point and subsequently exposed to temperatures above 800.degree. C. in air.

Method of making a toughened ceramic composite comprising chemical vapor

A fiber reinforced ceramic composite material exhibiting high tensile strength, high fracture toughness and high-temperature oxidation resistance is produced by simultaneously depositing a thin coating layer of refractory metal carbide with fugitive carbon onto the fiber reinforcement prior to the subsequent densification with the ceramic matrix. The energy behind propagating matrix cracks in the resulting composite material are effectively dissipated by crack deflection/branching, fiber debonding and frictional slip through the relatively weak and compliant fiber coating layer. These energy release and arrest mechanisms sufficiently impede the driving force behind unstable crack propagation and render the cracks non-critical, thereby serving to blunt and/or divert propagating matrix cracks at or around the reinforcing fiber. While significantly increasing the strength and fracture toughness of the composite, the compliant refractory fiber coating system enables the composite to remain oxidatively stable when stressed at or beyond the matrix cracking stress point and subsequently exposed to temperatures above 800.degree. C. in air.

Toughened ceramic composite materials comprising coated refractory

Multilayer fiber coating comprising alternate fugitive carbon and

An aircraft wing pivot structure is described which provides a flexible ring attached to the aircraft wing at flexible wing attachment points by spherical bearings. The ring is attached to the fuselage of the aircraft by pins fixed to the fuselage and fittings partially enclosing sliding shoes formed at the bottom edge of the ring to allow rotation of the wing. The wing is locked in the flight position by retractable pins connected to the primary fuselage attachment fittings. The ring is a unitary stainless structure which accepts wing strains induced by flight loads by flexing at the wing attachment points. The use of a flexible ring eliminates truss-like members mounted on spherical bearings used in conventional designs. The elimination of a substantial number of components by the use of a flexible ring substantially reduces the weight of the aircraft and improves the reliability.

Wing pivot structure

A ceramic fiber/ceramic matrix composite has ceramic fibers and a porous coating on the fibers. A ceramic matrix contacts the porous coating, the fiber and coating being immersed in the ceramic matrix. The porous coating is selected from the group including Si.sub.3 N.sub.4, SiC, ZrO.sub.2, Al.sub.2 O.sub.3, SnO.sub.2 and Ta.sub.2 O.sub.5. The pores are generally empty so as to render the coating frangible to promote fiber de-bonding and pull-out in the wake of an advancing crack in the matrix. In order to keep the pores empty, a non-porous sealing layer is formed over the porous coating which closes the pores without filling them. The ceramic matrix remains generally outside of the pores, whereby said pores remain empty after the fiber and coating are immersed in the ceramic matrix.

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Huntington Beach, CA, United States of America

Wayne S Steffier