Abstract: A method of forming a platinum aluminide diffusion barrier on a metallic substrate, eg a titanium alloy aerospace component, comprises applying to the metallic substrate a coating comprising particulate platinum and particulate aluminium in an organic carrier and performing a reaction treatment on the thus applied platinum and aluminium which causes the platinum and the aluminium to form an intermetallic diffusion barrier on the metallic substrate.

Abstract: A seal segment (66) as described for a seal segment ring (64) of a turbine (16) in a gas turbine engine (10). The seal segment (66) has an inner surface (70) adapted to face the turbine blades (36) in use. Path means (72) is defined in the seal segment (66). The path means (72) is adapted to extend, in use, generally parallel to the principal axis of the turbine and has downstream inlet means (74) through which a cooling fluid to cool the seal segment can enter the path means (72) and upstream outlet means (76) from which the cooling fluid can be exhausted from the path means (72). The cooling fluid can flow along the path means (72) in a generally upstream direction opposite to the flow of gas through the turbine.

Abstract: An alloy composition suitable for use as a single crystal seed comprises nickel and, in the proportion of 5 to 50 weight %, a further metal selected from the Transition Series of elements in Period VI of the Periodic Table of Elements. The further metal may be tungsten or tantalum. The alloy composition contains no component which forms an oxide layer at elevated temperatures, and in particular contains no aluminium or titanium. The alloy composition is suitable for use as a seed alloy for the casting of single crystal components such as aerofoils for gas turbine engines.

Abstract: A gas turbine engine fan blade containment assembly (38) comprising a generally cylindrical, or frustoconical, metal casing (40) which has an inner surface (62), an outer surface (64), an upstream flange (42) and a downstream flange (52). The outer surface (62) of the metal casing (40) is provided with a pattern of blind apertures (66) which extend radially inwardly from the outer surface (62) of the metal casing (40) between the flanges (42,52). The fan blade containment has reduced weight of the metal casing (40) of the fan blade containment assembly (38) for a large diameter turbofan gas turbine engine (10) but has unimpaired stiffness and penetration resistance.

Abstract: A rotor disc (14), for use in an electrical machine (10), has at least one circumferential rotor rim (16) mounted thereon. The rotor rim (16) comprises at least one row of alternate magnets (20) and laminated pole pieces (18). The laminations in each pole piece (18) are mounted concentrically on a bolt (22) that extends through the rotor disc (14). A clearance (23) is provided between the laminations in each pole piece (18) and the bolt (22). The clearance (23) insulates the bolt (22) from the laminated pole pieces (18), which are made from a ferromagnetic material such as silicon-iron alloy, to minimize power losses due to eddy currents.

Abstract: A method of manufacturing a gas turbine engine fan blade (10) comprises forming three metal workpieces (50,52,54). A metal slab (30) is upset forged at both ends (32,34) to produce a metal block (40) with increased thickness (42,44) extending from opposite surfaces (36,38). The metal block (40) is cut in an inclined path to form two of the metal workpieces (50,52). The metal workpieces (50,52,54) are assembled into a stack (56) so that the flat surfaces (38,42,46,48) are in mating abutment. Heat and pressure is applied across the thickness of the metal workpieces (50,52,54) to diffusion bond the metal workpieces (53,52,54) together to form an integral structure (100). The integral structure (100) is hot creep formed and superplastically formed to produce the required aerofoil shape and the thickened end is machined to form the blade root (26). The method enables thinner metallic workpieces with better microstructure to be used and increases the yield of metallic workpieces.

Abstract: A method of laser trepan drilling diffuser type holes in a component which comprises directing the beam of the laser such that it drills a diffuser section on the beam entry side of the hole with the beam exiting the hole without interfering with the remaining non-diffuser part of the hole.

Abstract: A metal is used as a predominant component of an outermost metallic portion of a ceramic-containing and metal-containing vibration damping coating for a metallic article, for the purpose of enhancing resistance of the coating to foreign object damage and/or erosion while substantially maintaining or enhancing vibration damping performance of the coating.

Abstract: The present invention relates to rotary friction welding and non-rotary motion friction welding, providing means for controlling ductilities of the components during the welding process so as to bias the welding process in favor of a first component or to match the ductilities of different components thereby facilitating the welding process.

Abstract: A thrust reverser cascade flow directing element (28) for a gas turbine engine (10) comprises a plurality of plates (30) and a plurality of flow directing vanes (40). At least one vane (40) extends between each pair of plates (30), the plurality of plates (30) are formed from sheet material and a single integral piece of ductile sheet material (32) forms the plurality of flow directing vanes (40). The single integral piece of ductile sheet material (32) has a plurality of longitudinally spaced apart apertures (36) and a plurality of longitudinally spaced apart sheet material portions (38) between the apertures (36) and the ductile sheet material (32) is bent at a plurality of longitudinally spaced positions such that each sheet material portion (38) defines one of the plurality of flow directing vanes (40).

Abstract: A three-stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36,40,44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (54,70,92). The fuel and air mixing ducts (54,70,92) have a plurality of air injection slots (62,64,76,98) spaced apart transversely to the direction of flow through the fuel and air mixing ducts (54,70,92). The air injection slots (62,64,76,98) extend in the direction of flow through the fuel and air mixing ducts (54,70,92) to the reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone (36,40,44). This reduces the generation of harmful vibrations in the combustion chamber (28).

Abstract: A device (10) for fatigue testing of materials comprises a frame (14), first and second clamping means (16,18) for holding a specimen (12) to be tested. First and second mounting means (20,22) mount the clamping means (16,18) on the frame (14). The mounting means (20,22) vibrationally isolate the clamping means (16,18) from the frame (14). Actuator means (24) moves the first clamping means (16) relative to the second clamping means (18) to apply a low cycle load on the specimen (12). Electrical insulating means (30) electrically insulate the frame (14) from the specimen (12). A shaker (26) is coupled to the second clamping means (18) to apply a high cycle load on the specimen (12). A detector (32) detects the vibration of the specimen (12) and sends an electrical signal to a control unit (42) which determines the resonant frequency of the specimen (12). The control unit (42) sends a signal to the shaker (26) to maintain the high cycle load at the resonant frequency of the specimen (12).

Abstract: A wall element for use as part of an inner wall of a gas turbine engine combustor wall structure is of cast construction and includes a plurality of cooling apertures provided therethrough and formed during the casting process. The cooling apertures may be located in positions where they could not be conventionally formed by laser drilling.

Abstract: An electrical conductor winding (70) comprises a plurality of laminates of electrical insulation (72). Each laminate of electrical insulation (72) has a slot (78) on one surface (76). Each laminate of electrical insulation (70) has an electrical conductor (82) arranged in the slot (78). An electrical connector (84) connects the electrical conductor (82) in one laminate of electrical insulation (78) with the electrical conductor (82) in an adjacent laminate of electrical insulation (72). The laminates of electrical insulation (72) are arranged such that the surface (74) of one laminate of electrical insulation (72) abuts and is bonded to the surface (76) of an adjacent laminate of electrical insulation (12). The laminates of electrical insulation (12) comprise a glass-ceramic material. The electrical conductor windings allow active magnetic bearings, electric motors and electric generators to be used at temperatures up to 500° C. for example in gas turbine engines.

Abstract: A phosphate bonded ceramic is used to provide a diffusion barrier on a titanium alloy substrate, conferring degradation (eg oxidation) resistance to the alloy. The substrate may, for example, be an aerospace component such as a part of a gas turbine engine.

Abstract: An electrical machine, such as a generator or motor, is incorporated in a gas turbine engine. The engine has compressor blades which are shrouded at. Beyond the shroud, an electrical machine is provided by rotor projections which run in a channel in flux cores, with which excitor coils are associated. The result is an electrical machine which is external to the combustion gas paths of the engine, for ready access, and can have optimized magnetic flux paths for efficiency. High relative speeds within the electrical machine provide further advantages.

Abstract: A fuel injector system that reduces and/or eliminates combustion instability. The fuel injector system includes a pilot fuel injector, a pilot swirler that swirls air past the pilot fuel injector, a main airblast fuel injector having an aft end, inner and outer main swirlers that swirl air past the main airblast fuel injector, and an air splitter located between the pilot swirler and the inner main swirler. The air splitter includes at least one aft end cone angled radially outboard and axially positioned downstream of the main airblast fuel injector aft end. The air splitter divides a pilot air stream exiting the pilot swirler from an inner main air stream exiting the inner main swirler to create a bifurcated recirculation zone.

Abstract: A thrust reverser cascade flow directing element (28) for a gas turbine engine (10) comprises a plurality of plates (30) and a plurality of flow directing vanes (40). At least one vane (40) extends between each pair of plates (30), the plurality of plates (30) are formed from sheet material and a single integral piece of ductile sheet material (32) forms the plurality of flow directing vanes (40). The single integral piece of ductile sheet material (32) has a plurality of longitudinally spaced apart apertures (36) and a plurality of longitudinally spaced apart sheet material portions (38) between the apertures (36) and the ductile sheet material (32) is bent at a plurality of longitudinally spaced positions such that each sheet material portion (38) defines one of the plurality of flow directing vanes (40).

Abstract: A black high temperature emissivity paint comprises 27.5 wt black pigment, 50.5% acrylic resin and 22 wt % silicone resin excluding solvent. The black pigment comprises (Co,Fe) (Fe,Cr)2 O4 and Ni. The black high temperature emissivity paint is applied to components of gas turbine engines and the gas turbine engine is run at the gas turbine engines normal operating conditions. The component coated with the black high temperature emissivity paint is viewed by an optical pyrometer and the optical pyrometer is used to determine the temperature of the component. The pyrometer measures the energy radiated by the component. The advantage of the black high temperature emissivity paint is that the colour, and hence the emissivity, remain unchanged at temperatures of 1100° C. and greater. This enables the pyrometer to be used without the need to recalibrate the pyrometer to take into account changes in emissivity of the black high temperature emissivity paint. It enables higher temperature use with more accuracy.

Abstract: A fan (22) for a turbofan gas turbine engine (10) comprises a fan rotor (24) carrying a first set of circumferentially spaced radially extending fan blades (28) and a second set of circumferentially spaced radially extending fan blades (30). The second set of fan blades (30) is arranged downstream of the first set of fan blades (28). The hub to tip ratio (R1/R2) of the first set of fan blades (28) is substantially the same as the hub to tip ratio (R3/R4) of the second set of fan blades (30) and the radius (R2) of the radially outer ends of the first set of fan blades (28) is less than the radius (R4) of the radially outer ends of the second set of fan blades (30). This increases the flow area of the fan (22) by about 7% compared to a conventional fan of the same radius and thus increases the mass flow by about 7% and/or increases the pressure ratio.