Abstract: Methods for and preforms for making fiber reinforced composites are disclosed. According to the invention, preforms which allow composites to be machined are provided. Also, preforms with a uniform debulking ratio are provided with non-uniform fiber placement. In addition, methods of forming composites have less material waste and allow more than one composite to be consolidated at one time.

Abstract: A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier.

Abstract: A system is provided for drilling through contiguous first and second plate members so as to avoid the formation of burrs at their interface. Using a jig, the plate members are held together at distant locations while assuming a desired mutual orientation in a longitudinally extending upright plane. Loosely suspended from a frame manually movable along the length of the jig, a horseshoe shaped yoke is positioned in a laterally extending upright plane and has a pair of depending legs straddling and adjacent to their associated plate members to be drilled. A hole finding pin on a first leg is manually inserted into a pilot bore provided in the first plate member. Thereupon, opposed clamps on the depending legs firmly engage the plate members in the region of the pilot bore. From the side of the second plate member, enlarged sized bores are drilled through the plate members axially aligned with the pilot bore.

Abstract: A system of fireproofing panels. The panels are light weight and easy to install. Lap joints are formed between the panels and simply secured with screws. No fireproofing material need be applied over the joints or the screws. In one embodiment, the panels are screwed to a corrugated underlayment. In an alternative embodiment, brackets are used to hold several panels in place around structural members. Also, the panels can be fabricated with a metal foil backing which acts as a radiation shield during a fire.

Abstract: A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier.

Abstract: In accordance with the invention there is provided a method of producing a densified carbon preform having interior a porous region of graded carbon-silicon carbide, carbon-silicon nitride or ceramic-ceramic composition.

Abstract: Nickel-base superalloy composition for the repair, coating or rebuilding of the surface of a superalloy substrate, such as a single crystal nickel-base superalloy, to impart thereto surface areas having improved high temperature properties such as hot corrosion resistance. The present compositions are applied by low heat-input welding processes, such as laser welding or plasma arc welding, and are formulated to provide hot corrosion resistance properties and yet to have good weldability properties. The composition contains, by weight percentages, 2-12.5 Cr, 6-17 Cr, 0.5-7 Mo, 0.5-4 Ta, 2.5-9.5 Al, 1-4 Re, 1.5-8.5 W, 0.01-2.5 Nb, 0.5-6 Ti, 0.01-0.7 Yt, 0.02-3.5 Hf, and balance Ni.

Abstract: A system for preheating air before it enters the combustion chamber of a gas turbine engine includes a recuperator which extends between, and is supported by, forward and rear headers. Cold air to be pre-heated by the recuperator flows through an entry passage in the forward header, then into and through a first conduit of the recuperator which extends the length of the recuperator. The air then flows through a plurality of cross conduits located at different locations along the length of the recuperator where it becomes heated. Flow of the now-heated air continues into a second conduit in which it is guided toward the combustion chamber. Sleeves are provided, respectively, in the entry passage of the forward header and in the first conduit of the recuperator for maintaining substantially constant the pressure differential between the first and second conduits at all locations along the length of the recuperator.

Abstract: A porous preform is densified by heating while emersed in a precursor liquid. Heating is achieved by passing a current through the preform or by an induction coil immersed in the liquid. Ways to control the densification process are also described.

Abstract: A system for testing and measuring hole elongation or deformation in a test article. The system includes a frame, a bearing member, and a referencing arm. The frame has a receiving area adapted to receive a portion of a test article. The bearing member is positionable into a hole of the test article. The referencing arm is movably connected to the frame and is adapted to signal the location of a portion of the test article relative to the bearing member. A distance measuring device is wholely supported on the frame and arm to allow the test article to be tested to catastrophic failure without risk of damaging the measuring device.

Abstract: A gas jet is positioned above the water nozzle of a system provided for ultrasonically detecting flaws in an article to be inspected. The water nozzle directs a substantially level water jet stream against an upright surface of the article as it is moved transversely of the nozzle. A transducer associated with the water nozzle transmits ultrasonic energy along the water jet stream toward the article, then receives echoes from flaws existing in the article. The gas jet directs toward the upright surface of the article a gas jet stream which is substantially parallel to, and vertically aligned with, the water jet stream. The gas jet stream serves to deflect the water splashing off the surface of the article after impact therewith and prevents the splashing water from descending toward and striking the water jet stream.

Abstract: A system for preheating air before it enters the combustion chamber of a gas turbine engine includes a recuperator which extends between, and is supported by, forward and rear headers. Cold air to be pre-heated by the recuperator flows through an entry passage in the forward header, then into and through a first conduit of the recuperator which extends the length of the recuperator. The air then flows through a plurality of cross conduits located at different locations along the length of the recuperator where it becomes heated by the flow of turbine exhaust gas. Flow of the now-heated air continues into a second conduit in which it is guided toward the combustion chamber.

Abstract: Net shape composite articles are made by a molding process. The molded preform is densified in a process where the rate of temperature increase is controlled to prevent distortion. The densified composite objects are impregnated with a secondary material to provide desirable properties such as strength, stiffness, or oxidation resistance. Diverse parts such as golf clubs and engine parts can be made by the process.

Abstract: A method is disclosed of making an integral structure comprised of inner and outer coaxial shells mutually supported so as to define an annular passageway between the shells. The integral structure may be an air inlet housing for a gas turbine engine and the inner shell may be a hub member having a generally cylindrical passage extending therethrough for rotatably receiving a drive shaft. The inner shell is formed by braiding on a shaped mandrel a plurality of fibers such as fiberglass, boron, carbon, or the like, to form an inner shell preform having an outer surface of revolution. A plurality of duct preforms are similarly formed on a conical mandrel, then removed, and administered onto an outer peripheral surface of a duct mold so as to define a modified shape.

Abstract: Creep resistant titanium aluminide alloy article consisting essentially of, in atomic %, about 45 to about 48 Al, about 1.0 to about 3.0 Nb, about 0.5 to about 1.5 Mn, about 0.25 to about 0.75 Mo, about 0.25 to about 0.75 W, about 0.15 to about 0.3 Si and the balance titanium. The article has a heat treated microstructure including gamma phase, alpha-two phase and at least one additional particulate phase including, one or more or W, Mo, and Si dispersed as distinct regions in the microstructure.

Abstract: A system for reducing the formation of NO.sub.x pollutants during the combustion of liquid fuel in a gas turbine engine. The system comprises introducing an externally modulated, rapidly-pulsed, oscillated or sinusoidal fuel flow delivery rate (generically referred to as "modulated") to produce a controlled degree of combustor air input flow oscillation and bulk flow oscillation within the combustor which enhances the fuel-air mixing rate and homogeneity within the combustor, decreases the residence time of transition fuel/air mixtures prone to NO.sub.x formation, and substantially decreases the NO.sub.x concentration in the resulting combustion gas product without creating a net pressure gain throughout the combustion chamber.

Abstract: A method is disclosed for developing the contours of forming tools for fabricating metal members of complex shape such as wing skin and fuselage panels for aircraft. A computer simulation is performed of the age forming process on a geometrical representation of a member having the material properties of a desired metal member. The age forming process includes the steps of: a) overforming an unformed member in a tool having a contour of smaller curvature than the contour of the desired member; b) constraining the unformed member in the overformed condition; c) applying a thermal aging cycle to the member; d) cooling the constrained member following the thermal aging cycle; and e) releasing the constrained member from the condition imparted by step (b) and allowing it to spring back to a dimensionally stable condition which defines the desired member having a surface contour of complex shape.

Abstract: method and apparatus for aligning a photoreceptor, such as a CCD array, at a back focal plane of a lens, as may be employed in the construction of a sensor of an imaging system, employs a pair of sine-wave gratings arranged perpendicularly to each other and disposed in front of the lens. An illuminating beam of collimated monochromatic light propagates through the gratings and the lens to form a two-dimensional diffraction pattern on the photoreceptor. Beam splitting optics are employed between a source of the illuminating beam and the gratings to split the illuminating beam into a first beam and a second beam which are inclined equally to an optical axis of the lens to produce two of the foregoing diffraction patterns offset from each other in a resulting composite diffraction pattern. Elements of the pattern undergo displacement from their correct positions in response to a tilting and/or displacement of the photoreceptor from its correct position and orientation in the back focal plane.

Abstract: A ceramic thin film applique provided on a substrate effects an optical transition at a predetermined elevated temperature. Below the transition temperature, the applique exhibits distinctive visual and physical characteristics, for example color, opaqueness and/or texture, but when the substrate is heated to the transition temperature, the visual and physical characteristics of the applique change noticeably. The invention encompasses the composition of the applique itself, as well as the methods of making the applique, applying it to the substrate, and using it.

Abstract: A system for detecting and removing foreign object debris from an enclosed region is capable of insertion through a small-sized opening. A source of light is optically transmitted through a first window in the outer peripheral surface of an elongated borescope adjacent its distal end to illuminate a debris containing region. An image of the region is transmitted through a second window in the distal end of the borescope to a remote television monitor. A vacuum conduit extends to a flexible tip end which is proximate to the distal end of the borescope and is connected to a source of vacuum to create a suction at the tip end. An elongated guide sleeve serves to slidably receive the vacuum conduit. The tip end of the vacuum conduit is movable relative to the guide sleeve between a retracted position substantially coincident with the first end of the guide sleeve and an extended position whereat the tip end of the vacuum conduit is distant from the first end.