Abstract: A ceramic thermal barrier coating system for superalloy components subjected to high operating temperatures, such as gas turbine engine airfoils, is disclosed which includes a high purity alumina interfacial layer between the metallic substrate and the ceramic overcoat in order to better resist failure by spalling.

Abstract: A high speed liquid vortex pump is fitted with a flexible tube in the discharge throat. The flow area of the flexible tube, and thus the pump output flow rate, is varied by surrounding the tube with a pressure modulated stream of the working fluid.

Abstract: An improved silicon nitride material characterized by high mechanical strength at high temperatures comprising a combination of approximately 0.5-6.0% by weight of strontium oxide, 2.0-12% by weight of yttrium oxide and the balance silicon nitride. The improved material is densified by either an encapsulated hot isostatic pressing method or an encapsulated sinter/HIP method and can be utilized to form near net shape articles.

Abstract: Abradable coatings are applied to turbine or compressor shroud structures to facilitate reductions in blade tip-to-shroud clearances for improved engine performance or airfoil durability. Coating compositions include a chemically table, soft, burnishable ceramic material (such as CaF.sub.2 or BaF.sub.2) in a ceramic or metallic matrix or honeycomb structure.

Abstract: A system for automatically controlling the buoyancy of a lighter-than-air craft by condensing water ballast from engine exhaust gases.

Abstract: Method and apparatus for controlling radial solidification in cast turbine wheel or nozzle assembly so as to produce an equiaxed fine grain structure in a hub portion and a directionally solidified grain structure in an integral blade portion by means of adjustable heat shields and heating elements disposed above and below the mold.

Abstract: Disclosed herein is a hydraulic to pneumatic power transfer unit which converts a high pressure oil flow into a flow of high pressure air by means of three stages of piston pumps and characterized by a first stage having a pair of linked pistons of substantially equal size both supplying air to a second stage piston which is directly linked to a third stage piston so that the pair of second and third stage pistons work alternately with the pair of first stage pistons and the linkage between each pair of pistons actuate spool valves which control the motion of the other pair of pistons.A further improvement is also disclosed in which an internal oil reservoir and a swash-plate pump is added to the system so that it may be powered by a rotating shaft instead of a flow of oil. In addition, the pulses of oil produced by the swash-plate pump directly control the piston pairs without the need for spool valves.

Abstract: A bleed flow modulator is used in conjunction with pressure regulating valves regulating bleed air pressure from each engine to a common manifold. The bleed flow modulator monitors the pressure drop across a heat exchanger, which pressure drop is proportional to flow rate of bleed air through the heat exchanger. By providing a limited authority negative feedback signal to the pressure regulating valve from the bleed flow modulator, flow rate of bleed air from each engine to the common manifold is kept near a desired uniform value, thereby achieving balanced flow extraction of bleed air from the aircraft engines.

Abstract: A single crystal nickel-base super alloy is disclosed having good high temperature strength with improved metallurgical stability and environmental resistance. The single crystal alloy of this invention is characterized by the addition of rhenium for high temperature strength, the inclusion of cobalt to increase metallurgical stability by inhibiting the formation of sigma phase, and the ellimination of vanadium to enhance hot corrosion resistance. The nominal composition of my new single crystal alloy is 8-10% Co, 5% Cr, 2% Mo, 5% W, 3% Re, 5.5% Al, 1.5% Ti, 6.3% Ta, and the balance Nickel.

Abstract: A bleed flow modulator is used in conjunction with pressure regulating valves regulating bleed air pressure from each engine to a common manifold. The bleed flow modulator monitors the pressure drop across a heat exchanger, which pressure drop is proportional to flow rate of bleed air through the heat exchanger. By providing a limited authority negative feedback signal to the pressure regulating valve from the bleed flow modulator, flow rate of bleed air from each engine to the common manifold is kept near a desired uniform value, thereby achieving balanced flow extraction of bleed air from the aircraft engines.

Abstract: An abradable ceramic coated turbine shroud structure includes a grid of slant-steps isolated by grooves in a superalloy metal shroud substrate. A thin NiCrAlY bonding layer is formed on the machined slant-steps. A stabilized zirconia layer is plasma sprayed on the bonding layer at a sufficiently large spray angle to cause formation of deep shadow gaps in the zirconia layer. The shadow gaps provide a high degree of thermal strain tolerance, avoiding spalling. The exposed surface of the zirconia layer is machined nearly to the shadow gap ends. The turbine blade tips are treated to minimize blade tip wear during initial abrading of the zirconia layer. The procedure results in very close blade tip-to-shroud tolerances after the initial abrading.

Abstract: An electrically controlled, fluid driven actuator valve, in which an electrical signal drives a solenoid, which at any one time operates one of two flexible valve elements which, when opened causes a fluid pressure differential in a piston like hydraulic actuator chamber, to thereby drive an actuator rod, which then acts on any device desired to be controlled. The valve is of simple design with a minimum of moving parts, and is especially useful in missile and aircraft applications.

Abstract: A compact turbine engine exhaust gas noise suppressor has a housing having a first chamber, a second chamber having an outlet and communicating with the first chamber through a transfer passage, and a third chamber communicating with the first chamber through a perforated dividing wall and having a resonant sound attenuator positioned therein. A sound absorbing member is positioned in the second chamber to create therein a serpentine flow path extending between the transfer passage and the outlet. The exhaust gas noise is attenuated by flowing the exhaust gas into the first chamber through a duct into which ambient cooling air is educted, and then forcing the exhaust gas outwardly through the serpentine flow path.

Abstract: A coating for protecting the surfaces of gas turbine components such as single crystal turbine blades and vanes, wherein the coating has a composition (in weight percent) consisting essentially of chromium, 15-35; aluminum, 8-20; tantalum, 0-10; tantalum plus niobium, 0-10; silicon, 0.1-1.5; hafnium, 0.1-1.5; yttrium, 0-1; cobalt, 0-10; and nickel, balance totalling 100 percent. A preferred coating, which is particularly desirable for use with single-crystal turbine blades and vanes, has a composition consisting essentially of chromium, 17-23; aluminum, 10-13; tantalum plus niobium, 3-8; silicon, 0.1-1.5; hafnium, 0.1-1.5; yttrium, 0-0.8; cobalt, 0-trace; and nickel, balance totalling 100 percent. A process for preparing the coated component is also described.

Abstract: A rotor-shaft assembly which includes a ceramic, solid hubbed turbine rotor having an integral stub shaft brazed within one end of a generally cylindrically shaped sleeve member. A metal shaft is either brazed or cold press fitted within the other end of the sleeve member in a torque transmitting relationship. The stub shaft is formed with an annular relief therearound in order to reduce the compressive forces acting on the stub shaft by the sleeve member.

Abstract: A cast austenitic stainless steel bushing for relatively high temperature turbocharger and automotive applications is provided having good hot hardness and hot strength properties and a co-effficient of thermal expansion approximating that of the parent housing alloy. Bushings made of this alloy have a composition in the range of 29-32% chromium; 4-8% nickel, 1.0-1.5% columbium and tantalum; 1.3-1.7% carbon, 0.25-0.45% sulfur, 0.3-0.4% nitrogen, up to 1.0% manganese, up to 1.0% silicon, up to 1.0% molybdenum, up to 0.1% phosphorous, balance iron.

Abstract: A laminated aluminum fluidic device is constructed by sequentially coating the facing side surfaces of the aluminum laminae with layers of zinc, nickel and solder, positioning the facing pairs of solder layers in intimate contact, and heating the coated laminae to fuse the facing solder layers.

Abstract: Disclosed is a method of, and apparatus for, flame spraying particulate material utilizing the thermal energy of a very hot gaseous primary stream produced in an oxy-fuel combustion chamber combined with kinetic energy from a surrounding annular sheath of warm high velocity secondary air.

Abstract: A process for refining metal in a crucible containing a layer of molten slag, wherein molten metal passes downwardly through the slag and resolidifies as an ingot thereunder. The slag is kept molten by passing electrical current through the slag layer and between a first electrode and a second electrode. The second electrode has liquid or gas cooling means as an integral part thereof. Current is passed between the first electrode and the second electrode through at least one electrically conductive member interposed between the slag and the second electrode. The electrically conductive member has a melting temperature above the melting temperature and below the bulk temperature of the slag. A portion of the surface of the electrically conductive member that is in contact with the slag has a temperature above the freezing temperature of the slag.

Abstract: Disclosed is an improved high velocity dual fuel burner and a method for firing a vertical shaft metal melting furnace with gaseous or liquid fuel in which the burner nozzle is adapted to mix and ignite both types of fuels alternately or in combination by means of three concentric nozzles including a central oil spraying nozzle, an intermediate nozzle to supply natural gas and an outermost nozzle to supply combustion air.