Abstract: Superalloy with a nickel base matrix having good mechanical properties when ot in respect of tensile strength, creep resistance, low cycle fatigue and resistance to crack-propagation of which the composition in percentages by weight is as follows: Cr 11 to 13; Co 8 to 17; Mo 6 to 8; Nb less than or equal to 1.5; Ti 4 to 5; Al 4 to 5; Hf less than or equal to 1; C, B, Zr each less than or equal to 500 ppm; Ni remainder to 100. The alloy can be manufactured advantageously by powder metallurgy techniques and used in the manufacture of turbo machine disks.

Abstract: A capacitive dimensional measurement chain with linear output is essentia comprised of a capacitive sensor formed by a central detection electrode and a guard electrode surrounding the detection electrode that are respectively powered by two a.c. bias voltage sources. The chain also comprises a reference capacitor and a measuring circuit for measuring the distance between the detection electrode and a conductive part placed facing the detection electrode. The bias voltage sources are variable level sources and are level-controlled by a distance measurement signal issued by the measuring circuit. The measuring circuit comprises a level amplifier and a demodulator for amplifying and demodulating an incoming error signal representative of a difference between a load of a sensor capacitance that is defined between the detection electrode and the part separated by the distance to be measured, and a load of the reference capacitor.

Abstract: Machine for ultrasonic abrasion machining of the type comprising an assem (1) supporting the parts (p) to be machined; a vibrating assembly (9) ending in a tool-holder (12) and adapted to drive the tool (8) with a reciprocal movement at ultrasonic frequency and to communicate these vibrations to an abrasive machining liquid; a system for the controlled descent of the tool towards the part to be machined, the attacking surface of the tool (8) being perpendicular to the axis of the tool-holder (12), so that the ultrasonic abrasion machining is carried out at the tool end; a device for regulating the downward movement of the tool; and, between the vibrating assembly (9) and a fixed frame (4), acousto-mechanical filters (20) disposed at longitudinal amplitude nodes (21, 22) of the vibrations, characterized in that an acousto-mechanical filter (20) is formed essentially of two concentric rings (23, 24) connected together by equidistant bridges (25), the inner ring (24) being deformable resiliently under the effect

Abstract: Velocimeter comprises a measuring volume (100) in a particle-laden fluid stream, means for brightly illuminating the measuring volume and means for measuring, based upon the light scattered by said particles when they are illuminated, the velocity of the said fluid stream, having a mosaic of optical fibers (10) and at least one optical system (101) for projecting a plane of the measuring volume onto the mosaic's input plane, the mosaic's outputs being connected to the velocity measuring means.

Abstract: A tridimensional electrostatic accelerometer comprises a cube-shaped test ight. On each of the six faces of the cube is a pair of conducting electrodes. A hollow cage accommodates the test weight and twelve electrodes on the cage to form, with the test weight electrodes, three sets of four capacitors C.sub.ij, where i varies from 1 to 4 and j is x, y and z respectively. Measurements are made for each value of j of the sums and differences of the capacities(C.sub.1 -C.sub.2).sub.j (C.sub.3 -C.sub.4).sub.j(C.sub.1 +C.sub.2).sub.j (C.sub.3 +C.sub.4).sub.jFrom these quantities voltages are derived for positioning the test weight. The voltages are applied selectively to the electrodes of the set of capacitors C.sub.ij.

Abstract: Electrical continuimeter device for checking the electrical continuity of a conducting layer covering a structure having conducting and non-conducting parts, said conducting layer being covered by an insulator layer. The device comprises a pick-up with an inner and an outer coaxial electrodes to be put on the insulator layer. A supply alternating voltage is applied between the inner electrode and the ground terminal of the structure developing a first voltage across a load resistor and a second voltage between the outer electrode and the ground terminal is measured. Components of the second voltage respectively cophasal and in phase quadrature with the first voltage are generated and these components are divided by the first voltage, thus providing the resistive and reactive components of the ground impedance.

Abstract: A sensing element for measuring atmospheric electrical field comprising a fixed detection electrode and a rotating modulator. Between the detection electrode and the rotating modulator there is interposed a fixed apertured screen, conductive of electricity and connected to the sensing element mass. The screen has a peripheral portion protruding relative to the modulator. The sensing element measures both slow field variations and abrupt field variations.

Abstract: The invention relates to a process for increasing the lifetime of a refrary composite material piece comprising a metallic matrix and a reinforcing phase consisting of aligned monocrystalline fibers made of a metallic carbide, when the piece has suffered a plastic deformation in the direction of said fibers. The invention consists in restoring the initial qualities of the piece by subjecting it to a high temperature, inferior to the melting point of the material, more precisely at the temperature at which the piece resumes its initial length after being cooled at ambient temperature. The invention is particularly applicable to pieces forming turbine blades for aircrafts.

Abstract: Device for measuring the speed of a fluid in a tube which comprises two uasonic electro-acoustic transducers in the tube; means for energizing these transducers by first and second transmit pulse groups; means for receiving first and second receive pulse groups at the transducer output; means for measuring a first delay between the start of the first transmit pulse group and the start of the first receive pulse group and a second delay between the start of the second transmit pulse group and the start of the second receive pulse group; and means for measuring a third delay between the starts of the first and second receive pulse groups. The flow rate is proportional to the quotient of the third delay by the product of the first and second delays. These delays comprise an integer delay part which is measured by clock pulses counting and fractional delay parts which are measured by constant current integrators.

Abstract: A refractory composite material has a nickel-based matrix, containing chromium, hardened by elements such as W in solid solution and hardened by precipitation of a .gamma.'(Ni,Xi).sub.3 (Al,Yi) phase, Xi representing elements different from Ni and Yi elements different from Al which the matrix may contain and which are respectively substituted for Ni and Al atoms in the formation of the .gamma.' precipitate, and with aligned monocrystalline fibers of a transition metal monocarbide, preferably niobium monocarbide, imbedded in said matrix, as obtained by unidirectional solidification. The chromium proportion of the material is maintained at a value lower than that from which the chromium carbide of formula Cr.sub.23 C.sub.6 is formed in the matrix at the expense of the niobium carbide of the reinforcement fibers at the operating temperatures foreseen for the material.

Abstract: A method and apparatus for manufacturing bars made of an alloy by unidireonal solidification. The mold is moved relative to a hot source and a cold source disposed below the hot source. The relative positions of the two sources as well as their efficiency and the displacement speed of the mold are set so that there is established within the alloy contained in the mold a planar solidification front with a high thermal gradient at the level of the front, and so that there is produced an orientation of the structure of the alloy which is perpendicular to the solidification front. During the whole duration of the solidification, the mold is fed with alloy powder having the required nominal composition at the rate corresponding to the quantity of alloy solidified per unit of time.

Abstract: A device for producing a gaseous stream carrying electric charges, particrly in view of influencing the electric voltage of a body, particularly of an airship such as a helicopter, comprising a metallic needle connected to a first pole of a high voltage electric source and having a point which is arranged in the neck of a metallic nozzle supplied with a source of compressed air to create a stream carrying the electric charges, the nozzle being arranged at one end of an electrically insulating hollow duct means for ejecting the stream towards the atmosphere, the ejection opening of the stream being surrounded by a massive hood made of an electrically insulating material.

Abstract: The invention relates to a centrifugal compressor comprising an impeller not comprising distributor blading upstream of the impeller, a pressure probe and regulator means controlled by the probe and arranged to act on the flow conditions downstream or upstream of the compressor to avoid the risk of surging. The probe is disposed upstream of the impeller of the compressor and being arranged to detect the critical direction of the absolute velocity of the fluid and to measure the critical value of the radial gradient of the static pressure beyond which the compressor runs the risk of being subjected to surging.

Abstract: An air-navigational beacon, designed to simulate an imaginary circular ben with a multiplicity of pairs of diametrically opposite dipoles excited in cyclic succession, comprises an array of stationary dipole pairs disposed along lines parallel to a given direction. The spacing of the dipoles of each pair varies from one pair to another according to a sinusoidal law in their order of energization. The two dipoles of a pair are energized in relative quadrature and with a signal amplitude proportional to their spacing.

Abstract: A method of manufacturing a mold adapted to be used for casting bodies of ber-reinforced composites. A model of the body to be cast is prepared and coated with a one piece dense shell of refractory metallic oxide deposited by plasma or flame spraying and the model is then separated from the shell by conventional physical or chemical treatment.

Abstract: In a procedure of preparing fibrous metal material by electrolytically deiting metal on conductive fibres forming a skeleton, the fibres are carded during deposition of the metal. The fibres are carded in a rotatable drum containing a fibre carding device which operates during rotation of the drum to card fibres whilst metal is being electrolytically deposited on the fibres.

Abstract: In the process of forming a coating selected from nickel and cobalt-based atings on a surface of a component made of a metallic material having a total composition by weight comprising at least 50% of metal selected from the group consisting of iron, cobalt and nickel, the improvement comprising forming at least one layer of an alloy of boron with one of nickel, cobalt and nickel/cobalt on the component, after which the boron is eliminated.

Abstract: In a system for use in helicopter navigation antennas are carried at the e ends of each of the blades of the rotor of the helicopter. Radio waves transmitted by a beacon at a known location on the ground are received by the antennas and phase modulated by their rotation. On the rotor the signals are amplified and mixed with oscillations from local oscillators and are detected with the aid of reference signals from the local oscillators. By means of slip rings and contact brushes the signals are introduced into the body of the helicopter where they are first multiplied with each other and then filtered so as to produce phase-modulated signals with a carrier suppressed which are supplied to an electroluminescent diode illuminating a rotating-disc light modulator with a light-transmitting function which is analogous to the phase modulation of the signals received by the antennas. The light beam passing through the disc is integrated in a vidicon and displayed on a screen.

Abstract: The invention provides a method, an appliance and an installation for the termination of small displacements of points on the surface of a solid body.A catadioptric covering, such as a catadioptric paint or a piece of a sheet with catadioptric properties is applied on the point of the solid body whose displacement is to be determined, and after illuminating said covering, one determines in a viewing direction different from that of the displacement the variations in the quantity of light received by a photosensitive receiver coming from an image of the said covering in the plane of which is located a knife-edge partly covered by the said image.

Abstract: High-frequency waves transmitted by a rotating antenna array at a ground tion are intercepted by an airborne receiver for photoelectric evaluation by one or more discs whose light transmissivity, by translumination or reflection, varies periodically according to a sinusoidal law in one diametral direction while being constant in another diametral direction orthogonal thereto. The disc or discs are rotated at a speed corresponding to that of the transmitting antenna array, under the control of periodic synchronizing pulses, and are illuminated by a flux modulated by an electrical signal derived from the incoming wave, this signal containing a phase component dependent on two spatial coordinates such as elevational and azimuthal angles determining the relative position of the ground transmitter and the airborne receiver.