Abstract: The invention relates to steel which is characterized by the following composition as expressed in percentages by weight: —C=0.18 0.30%, —Co=5-7%, —Cr=2-5%, —Al=1-2%, —Mo+W/2=1-4%, —V=trace 0.3%, —Nb=trace 0.1%, —B=trace?50 ppm, —Ni=10.5-15% with Ni?7+3.5 Al, —Si=trace 0.4%, —Mn=trace 0.4%, —Ca=trace?500 ppm, —Rare earths=trace?500 ppm, —Ti=trace?500 ppm, —O=trace?200 ppm if the steel is obtained by means of powder metallurgy or trace?50 ppm if the steel is produced in air or under a vacuum from molten metal, —N=trace?100 ppm, —S=trace?50 ppm, —Cu=trace?1%, and —P=trace?200 ppm, the remainder including iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Abstract: The invention relates to steel which is characterized by the following composition as expressed in percentages by weight:—C=0.18 0.30%, —Co=5-7%, —Cr=2-5%, —Al=1-2%, —Mo+W/2=1-4%, —V=trace 0.3%, —Nb=trace 0.1%, —B=trace?50 ppm, —Ni=10.5-15% with Ni?7+3.5 Al, —Si=trace 0.4%, —Mn=trace 0.4%, —Ca=trace?500 ppm, —Rare earths=trace?500 ppm, —Ti=trace?500 ppm, —O=trace?200 ppm if the steel is obtained by means of powder metallurgy or trace?50 ppm if the steel is produced in air or under a vacuum from molten metal, —N=trace?100 ppm, —S=trace?50 ppm, —Cu=trace?1%, and —P=trace?200 ppm, the remainder comprising iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Abstract: The invention relates to steel which is characterized by the following composition as expressed in percentages by weight: —C=0.18 0.30%, —Co=5-7%, —Cr=2-5%, —Al=1-2%, —Mo+W/2=1-4%, —V=trace 0.3%, —Nb=trace 0.1%, —B=trace—50 ppm, —Ni=10.5-15% with Ni?7+3.5 Al, —Si=trace 0.4%, —Mn=trace 0.4%, —Ca=trace—500 ppm, —Rare earths=trace—500 ppm, —Ti=trace—500 ppm, —O=Trace—200 ppm if the steel is obtained by means of powder metallurgy or trace—50 ppm if the steel is produced in air or under a vacuum from molten metal, —N=trace—100 ppm, —S=trace—50 ppm, —Cu=trace—1%, and —P=trace—200 ppm, the remainder including iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Abstract: A fabrication method of fabricating a thermal barrier covering a superalloy metal substrate, the thermal barrier including at least an underlayer and a ceramic layer, the method including: smoothing a surface state of the underlayer by at least one physicochemical and/or mechanical process prior to depositing the ceramic layer such that a number of defects presenting a peak-to-peak difference lower than or equal to 2 ?m is at most five over any distance of 50 ?m, and then depositing the ceramic layer. The method can be applied to turbine blades.

Abstract: A method of angle rounding at an intersection between two surfaces of a workpiece, the method including machining away a minimum volume of material from the intersection of the two surfaces, thereby giving a convex rounded shape to the intersection of the two surfaces, the curved shape being located relative to the workpiece on the outside of a circular arc tangential to the two surfaces at the point where the curved shape connects with the two surfaces.

Abstract: The invention relates to steel which is characterized by the following composition as expressed in percentages by weight: —C=0.18 0.30%, —Co=5-7%, —Cr=2-5%, —Al=1-2%, —Mo+W/2=1-4%, —V=trace 0.3%, —Nb=trace 0.1%, —B=trace?50 ppm, —Ni=10.5-15% with Ni?7+3.5 Al, —Si=trace 0.4%, —Mn=trace 0.4%, —Ca=trace?500 ppm, —Rare earths=trace?500 ppm, —Ti=trace?500 ppm, ?O=trace?200 ppm if the steel is obtained by means of powder metallurgy or trace?50 ppm if the steel is produced in air or under a vacuum from molten metal, —N=trace?100 ppm, —S=trace?50 ppm, —Cu=trace?1%, and —P=trace?200 ppm, the remainder including iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Abstract: The invention relates to steel which is characterized by the following composition as expressed in percentages by weight: —C=0.18 0.30%, —Co=5-7%, —Cr=2-5%, —Al=1-2%, —Mo+W/2=1-4%, —V=trace 0.3%, —Nb=trace 0.1%, —B=trace-50 ppm, —Ni=10.5-15% with Ni?7+3.5 Al, —Si=trace 0.4%, —Mn=trace 0.4%, —Ca=trace-500 ppm, —Rare earths=trace-500 ppm, —Ti=trace-500 ppm, —O=trace-200 ppm if the steel is obtained by means of powder metallurgy or trace-50 ppm if the steel is produced in air or under a vacuum from molten metal, —N=trace-100 ppm, —S=trace-50 ppm, —Cu=trace-1%, and —P=trace-200 ppm, the remainder including iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Abstract: The invention provides a method of fabricating a turbine stator casing, the method comprising the operations consisting in: between the walls of portions of a mold, forming a cavity of shape corresponding to the shape of the shroud of said casing, securing soluble cores to at least one of said mold portions, said cores being held at a distance from the wall of said mold portion and representing empty spaces that are to be formed inside said shroud; putting soluble inserts into place between the cores to represent flow paths between said empty spaces; filling said cavity with a metal alloy powder; sintering said powder by hot isostatic pressing; eliminating the cores and the inserts by dissolving them; and extracting the shroud as molded in this way. The invention is applicable to fabricating a turbine stator casing for an airplane turbojet.

Abstract: The invention relates to a turbomachine part comprising a main portion and a leading edge. Over at least a fraction of the length of said part, the leading edge is constituted by a sheet of material that is fastened to the main portion and that extends from the pressure side to the suction side of the main portion while leaving a space between the sheet and the upstream end of the main portion, said material being capable, below a maximum deformation ?2, of responding to an impact against a foreign body by deforming reversibly in superelastic manner without damaging the main portion.

Abstract: The present invention provides non-axially symmetrical manufactured parts of thickness less than 10 mm, made of ? or quasi-? titanium alloy, having a core microstructure constituted by whole grains presenting a slenderness ratio greater than 4 and an equivalent diameter lying in the range 10 ?m to 300 ?m. The invention also provides a method of manufacturing the parts by forging.

Abstract: The invention relates to steel which is characterised by the following composition as expressed in percentages by weight:—C=0.18 0.30%, —Co=5-7%, —Cr=2-5%, —Al=1-2%, —Mo+W/2=1-4%, —V=trace 0.3%, —Nb=trace 0.1%, —B=trace?50 ppm, —Ni=10.5-15% with Ni?7+3.5 Al, —Si=trace 0.4%, —Mn=trace 0.4%, —Ca=trace?500 ppm, -Rare earths=trace?500 ppm, —Ti=trace?500 ppm, —O=trace?200 ppm if the steel is obtained by means of powder metallurgy or trace?50 ppm if the steel is produced in air or under a vacuum from molten metal, —N=trace?100 ppm, —S=trace?50 ppm, —Cu=trace?1%, and —P=trace?200 ppm, the remainder comprising iron and the inevitable impurities resulting from production. The invention also relates to a method of producing a part from said steel and to the part thus obtained.

Abstract: A turbomachine comprising at least a first rotary assembly with a first shaft, a stator, and bearings secured to the stator and suitable for supporting the shaft, one of the bearings being capable of giving way when an unbalance occurs in the rotary assembly, at least one segment of the shaft being covered in a covering which comprises at least one piece of fabric impregnated with resin and which is for coming into contact with a surrounding portion of the turbomachine when the unbalance occurs in order to protect the first shaft and ensure that there is no risk of the first shaft rupturing. The turbomachine is intended to be used mainly in the field of aviation, and more particularly as an airplane turbojet.

Abstract: A turbomachine including at least a first rotary assembly with a first shaft, a stator, and bearings secured to the stator and suitable for supporting the first shaft, one of the bearings being capable of giving way when an unbalance occurs in the first rotary assembly. The turbomachine further comprising brake arrangement for braking the first shaft when the unbalance occurs, and bond arrangement acting at the end of braking to bond a portion of the first shaft to a surrounding portion of the turbomachine. The turbomachine is intended to be used mainly in the field of aviation, and more particularly as an airplane turbojet.

Abstract: In the method, a support is provided presenting an annular base for a wiper, and the projecting portion of the wiper is built up by depositing successive layers on the base by performing the following steps: activating both a laser source connected to an optical head focused on a point of the surface of the top of the base and a source of powder that is connected to a spray nozzle, thereby forming a localized melt at said point, with the powder being injected into the melt, thereby forming a localized region of extra thickness; and aiming the optical head and the nozzle on another point adjacent to said region of extra thickness, and returning to the preceding step, until a layer has been formed over substantially the entire base.

Abstract: The method of the invention enables a coating to be made on at least one face to be protected of a metal substrate and/or article in order to improve its performance in terms of resistance to wear by friction, in particular at high temperature. The method comprises the following steps: providing a flexible sheet derived from at least one plate obtained by the technique of casting a strip by silkscreen printing from a viscous material made of a binder and a metal powder of a superalloy; cutting said flexible sheet to the dimensions of said face to be protected of a metal substrate and/or article in order to constitute a preform; placing said preform on said face to be protected of a metal substrate and/or article; and raising the assembly to a temperature enabling a coating to be formed by establishing a bond between said preform and said face to be protected.

Abstract: A turbine stator casing comprising a jacket and fastener hooks for fastening a turbine distributor nozzle, the hooks projecting from the inside face of the jacket, said jacket being made of a first alloy by hot isostatic compression using metal powder, said fastener hooks being made out of a second alloy that is more refractory than the first, and being secured to said jacket by diffusion welding during the hot isostatic compression. The casing also comprises inserts passing through the fastener hooks and through said jacket. These inserts, which are likewise secured to the jacket by diffusion welding, serve during manufacture of the casing to fasten the hooks to a mold portion inside which the jacket is formed. The invention is applicable to the turbines of airplane turbojets.

Abstract: According to the method, a blade is provided having at least one base for a rim at its free end, and the projecting portion of the rim is built up by depositing successive layers on the base by performing the following steps: activating a laser source connected to an optical head focused on a point of the surface of the top of the base and activating a powder source connected to a spray nozzle, whereby a localized melt is formed at said point, into which the powder is injected, thereby forming a localized region of extra thickness; and aiming the optical head and the nozzle on another point adjacent to said region of extra thickness and returning to the preceding step until a layer has been formed over substantially the entire base.

Abstract: In the method, a support is provided that presents a base for an annular wiper, and a wiper is built up that presents height that varies around its circumference, by forming a plurality of projecting portions by performing following successive steps: a laser source connected to an optical head focused on a point on the top surface of the base is activated, as is a source of powder connected to the spray nozzle, thereby forming a localized melt at said point, into which the powder is injected, thus forming a localized region of extra thickness; and the optical head and the nozzle are aimed at another point adjacent to said region of extra thickness and the method returns to the preceding step until the layer of material is completed in the angular sector in question.

Abstract: The invention provides a thermomechanical turbomachine part that is circularly symmetrical about a longitudinal axis, in particular a rotor, the part including at least one annular wiper for a sealing labyrinth. In characteristic manner, the wiper presents height in the radial direction that varies around its circumference by forming a plurality of projecting portions.

Abstract: The invention relates to an assembly for the mounting of the foot (121) of a blade, fixed or movable, of a turbomachine, made of metal, in the aperture (101) of a support made of metal, such as a casing, a fixed flange or the disk (10) of a rotor. Characteristically, this assembly comprises, between the foot (121) and the aperture (101), a non-metallic film (20), coated or impregnated with an adhesive, in particular a fabric of glass fibres and/or polyamide fibres, advantageously comprising polytetrafluoroethylene. Application for the mounting of blades (12) of the fan on the disk (10) of the rotor, or for the fixed and/or movable blades of a compressor, in particular a low-pressure compressor.