Dunlop Gmbh

Dunlop Limited a British Company

Dunlop Aerospace Limited

Ronald Fisher

Maurice J Evans

Keith A Williams

Thomas G Fennell

Norman Smith

Trevor C Wells

Sharon L Faulkner

Paul Hadlum

David Callum Johnson

Alan Frank Tibbatts

Lynda M Perks

John Victor Weaver

A method of deposing a carbon-containing substance in the pores of a porous body comprises establishing an open varying magnetic field flux loop and placing the body such that a magnetic field flux generated by the open magnetic field flux loop passes through a region of said body and heats that region, creating a thermal gradient across the body and bringing a thermally decomposable carbon-containing gas into contact with the heated region, thereby depositing a carbon-containing substance in the pores if said heated region.

Densification

At least one layer of fibers of a material susceptible to heating by electromagnetic radiation is incorporated in a porous structure. The structure is subjected to the radiation to heat up the body which is contacted with hydrocarbon gas to cause the gas to deposit carbon within the porous structure and thereby cause densification.

Densification of a porous structure (II)

A method for the densification of a porous structure comprises providing the structure with a body of material (,) which includes a susceptor element foil (,) which is more susceptible to heating by electromagnetic radiation than the other material (,) of the body, exposing said porous structure to hydrocarbon gas and simultaneously applying an electromagnetic field to said porous structure whereby said susceptor element (,) at least in part causes heating of the porous structure to a temperature at which the gas infiltrating the porous structure deposits carbon within the porous structure.

Densification of a porous structure

A method for the densification of an annular body having a porous structure and comprising layers of fabric, which includes locating a susceptor element within the porous body, the amount of the susceptor element occupying less than 5% of the volume of the porous body, the susceptor element being in the form of a layer comprising one of a foil and a fiber and having plural holes therein through which adjacent layers of fabric of the porous body contact each other, said susceptor element being made of a material which is more susceptible to heating by electromagnetic radiation than the material of the porous body, and exposing the porous body to hydrocarbon gas and simultaneously applying an electromagnetic field to the porous body, the susceptor element within the porous body at least in part causing heating of the porous body to a temperature at which the gas infiltrating the porous body deposits carbon within the porous body.

Densification of a porous structure (III)

An aircraft disc stack (1) comprises a plurality of interleaved stator and rotor discs (3,4) keyed respectively to a torque tube (5) and a wheel hub (not shown). The stack (1) further comprises bi-functional friction/load-transmitting discs in the form of end stator discs (10,13). These discs (10,13) are subject to uneven loading because the non-friction surfaces (12,15) are in use compressed on areas less than the load bearing areas of the opposing friction faces (11,14). This can lead to premature disc failure and in the past load spreader plates have been used to distribute loading over these areas to minimize the risk of failure. In this invention portions of the load bearing areas of non-friction surfaces (12,15) are toughened ie: material underlying these surfaces is toughened, to increase their resistance to deformation, fracture and/or wear thereby removing the need for additional load spreader plates which were hitherto required.

Toughened carbon composite brake discs

In a composite brake disc such as a carbon composite brake disc having reinforcement provided by layers of carbon fibre material, the drive region is provided with additional reinforcement to that of the friction region by laying or otherwise providing additional fibre reinforcement material substantially uniformly in the drive region.

Composite brake disc

In a method of making a carbon fibre preform such as for use in the manufacture of a friction disc a compressible body of carbon fibre or carbon fibre precursor material is acted upon by compressing means to compress the body to a required thickness and then operated upon by means such as a barbed needle-punch needle for a stitching thread which penetrates substantially the whole thickness of the body whereby the compressed preform may be removed from action by the compressing means in a free-standing and compressed state. If the method uses carbon fibre precursor material, that is then subjected to carbonization.

Manufacture of carbon fibre preform

A method for the manufacture of a light-weight panel, e.g. for aircraft, comprising preparing a panel preform having a pair of surface members or skins (29, 30) separated and supported by an internal core (26-28) in which spaces or interconnected pores provide vents to an edge of the panel, the wall surface members and the core comprising fibrous material, which may be carbon fibre, and using a pyrolysis process such as CVD to form a pyrolyric matrix around the fibres within the fibrous material, there being a flow of gas through the vents during the pyrolysis process.

Light-weight, high-strength, stiff panels

An aircraft disc stack (1) comprises a plurality of interleaved stator and rotor discs (3,4) keyed respectively to a torque tube (5) and a wheel hub (not shown). The stack (1) further comprises bi-functional friction/load transmitting discs in the form of end stator discs (10,13). These discs (10,13) are subject to uneven loading because the non-friction surfaces (12,15) are in use compressed on areas less than the load bearing areas of the opposing friction faces (11,14). This can lead to premature disc failure and in the past load spreader plates have been used to distribute loading over these areas to minimize the risk of failure. In this invention portions of the load bearing areas of non-friction surfaces (12,15) are toughened ie: material underlying these surfaces is toughened, to increase their resistance to deformation, fracture and/or wear thereby removing the need for additional load spreader plates which were hitherto required.

Method of fabricating a multi-ply carbon fibre fabric, preform or composite material from a layer of unidirectionally aligned carbon fibres of ultra-high modulus and a layer of low modulus carbon fibre comprising the steps of: arranging in superimposed relationship the layer of unidirectionally aligned carbon fibres of ultra-high modulus and the layer of low modulus carbon fibres so that at least a substantial number of the fibres of low modulus are disposed transversely of the fibres of the ultra-high modulus fibre layer, and connecting the two layers by interlacing fibres of the layer of low modulus fibres with those of the layer of ultra-high modulus fibres by needle-punching using felting needles orientated and configured so that their barbs snag only the low modulus fibres during passage through the layers.

Ultra-high performance carbon composites

A method for the manufacture of a light-weight panel, e.g. for aircraft, comprising preparing a panel preform having a pair of surface members or skins separated and supported by an internal core in which spaces or interconnected pores provide vents to an edge of the panel, the wall surface members and the core comprising fibrous material, which may be carbon fiber, and using a pyrolysis process such as CVD to form a pyrolytic matrix around the fibers within the fibrous material, there being a flow of gas through the vents during the pyrolysis process.

Method of producing light-weight high-strength stiff panels

A coated carbon-carbon composite of the kind incorporating carbon fibres in a carbon matrix also incorporates in at least a region (2) thereof other fibres of a different axial coefficient of thermal expansion from that of the carbon fibres, the other fibres being arranged in relation to adjacent carbon fibres so as to provide in combination with the carbon matrix a coefficient of thermal expansion of that region (2) of the composite which is compatible with that of an anti-oxidation coating (1) on the surface of that region.

Carbon-carbon composite materials

A carbon-carbon composite friction disc is formed from two or more carbon-based structural components secured together by an interface layer which is not itself a structural member but is fusion-bonded to both of the structural components to secure them together. The interface layer may be of metallic material such as a brazing compound, or may be of non-metallic material such as pitch.

Bonding of carbon-based components

A load-bearing thermal insulator, for example a brake piston thrust transmission element, which comprises platelets or flakes of thermally insulating material dispersed in a metal matrix and oriented normal to the direction of heat flow so as to impede the flow of heat through the matrix in one direction.

Load-bearing thermal insulator

In the production of all-carbon composite articles by the cracking of a hydrocarbon gas to deposit carbon on a fibrous carbon substrate the substrate is held in the furnace by a ram movable in the furnace to engage the substrate. The gas is introduced inside the annular substrate and evacuated at a position spaced laterally from the substrate so that the gas is forced to disperse through the substrate wall.

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Rugby, United Kingdom

Ronald Fisher