Abstract: A gas turbine engine comprises (A) a turbine including a nozzle and shroud assembly supported within the engine; the nozzle and shroud assembly including an inner annular ring member, an outer annular ring structure and a plurality of airfoils being positioned between the inner and outer ring structure, wherein at least one of the airfoils of the plurality comprises; (i) a substrate comprising a first electrically conducting material; and (ii) a wire of dissimilar electrically conducting material extending a measured distance in intimate contact with the substrate at a reference point and electrically insulated to a measuring point.

Abstract: An improved high performance x-ray system having a rotating anode therein which includes an improved coating for the x-ray tube rotor. The surface of the x-ray tube rotor is coated with a ductile, metal coating, preferably iron, having a thickness of about 0.2 to about 5.0 mils thick. The rotor coating has ductile properties with a strain to fail greater than 0.05% and thermal expansion properties which when placed on an x-ray tube rotor, provides at least about 40,000 x-ray scan-seconds prior to tube failure due to rotor spalling.

Abstract: An improved high performance x-ray system having a rotating anode therein which includes an improved coating for the x-ray tube rotor. The surface of the x-ray tube rotor is coated with a ductile coating wherein at least about 40,000 x-ray scan-seconds are accomplished prior to tube failure due to spalling. The coating may be a ductile alloy such as Rene' 80 having a thickness of about 0.2 to about 5.0 mils thick and may be even thicker. The rotor coating has ductile properties with a strain to fail greater than 0.05% and thermal expansion properties which when placed on an x-ray tube rotor, provides at least about 40,000 x-ray scan-seconds prior to tube failure due to rotor spalling.

Abstract: A method for forming a ring structure having a high volume fraction of a filament reinforcement within a metal matrix is disclosed. The ring structure is formed by consolidating a set of nested rings each of which has a high volume fraction of the filamentary reinforcement therein. The nesting is done to provide a clearance between the rings of the nest of about 2 or 3 mils. The nested rings are enclosed within a HIPing can and the structure is HIPed at about 15 ksi and 1000.degree. C. for over an hour. A single superring structure results from the HIPing.

Abstract: A method for asymmetrically consolidating a ring structure having a filamentary reinforcement embedded in a plasma sprayed deposited matrix is taught. The method involves fabricating a filament reinforced plasma sprayed deposit matrix structure and asymmetrically consolidating the structure. The asymmetric consolidation is accomplished by placing a thicker and/or stronger can surface on the outer portions of the ring structure and a thinner and/or weaker can structure on the inner and side surfaces of the reinforced ring structure. The HIPing of the reinforced ring structure with the asymmetric can results in a preferential compaction of the ring from the inside toward the outside and avoids the buckling of and damage to the reinforcement filaments on the outer portions of the structure.

Abstract: A method for forming a ring structure having a high volume fraction of a filament reinforcement within a metal matrix is disclosed. The ring structure is formed by consolidating a set of nested rings each of which has a high volume fraction of the filamentary reinforcement therein. The nesting is done to provide a clearance between the rings of the nest of about 2 or 3 mils. The nested rings are enclosed within a HIPing can and the structure is HIPed at about 15 ksi and 1000.degree. C. for over an hour. A single superring structure results from the HIPing.

Abstract: A low frequency RF plasma spray deposition method is provided, which is especially effective in reducing losses and improving particle heating. In one aspect of the invention, an RF plasma gun is operated in the frequency range below 1 MHz and an argon-helium mixture to which a third component, such as hydrogen, can also be admixed, is substituted for the standard argon-hydrogen mixture used at frequencies above 2 MHz. In another aspect of the invention, a RF plasma gun is operated in the frequency range of 400-500 kHz and specific start up and operating procedures and conditions are set forth for successful deposition of titanium and refractory metal alloys.

Abstract: A method of controlling the internal dimensions of a filament reinforced ring structure is taught. The method involves providing the ring structure with an internal dimension which is slightly smaller than the specification of the final dimension which is sought. The ring structure is mounted over a solid mandrel having a coefficient of thermal expansion which is greater than that of the ring structure. The solid mandrel is mounted within the ring structure and the combination is heated to a temperature at which the outer dimension of the mandrel is greater than that of the internal dimension of the ring structure. The result is to enlarge the internal dimensions of the ring structure to a value conforming very closely to a specification for the ring structure.

Abstract: A method for joining substrates of the active metals, such as niobium, tantalum, and titanium, and alloys of the active metals is disclosed. The substrates are joined in a deposit zone traversing areas to be joined on the substrates. The areas to be joined are formed to have deposit receiving surfaces that will form a diffusion bond with a spray deposit. An active metal or an alloy of an active metal compatible with the substrates to be joined is provided as a powder for plasma spraying. The substrates are disposed in a radio frequency low-pressure plasma-spray apparatus to receive a spray deposit on the deposit receiving surfaces in the zone. The deposit receiving surfaces are preheated and cleaned by passing the surfaces in heat coupling relation by the plasma, and placing the substrates at a negative DC potential relative to the plasma. A transferred arc from the radio frequency plasma-spray apparatus to the surfaces is generated that cleans the surfaces.

Abstract: A method for controlling the dimension of a reinforced metal matrix composite structure is taught. The structure is annular and the method is to render the structure non-round where the initial structure is essentially round. The cure of the essentially round condition is accomplished by forming a solid mandril very slightly smaller in dimensions than the final dimensions sought for the structure. The essentially round composite ring is forced onto the non-round mandril and heated to the relaxation temperature of the matrix. Because the mandril has a higher thermal coefficient of expansion than the matrix, the method is effective in forming an essentially round structure into a non-round configuration.

Abstract: A method for forming a shaft of filament reinforced matrix metal is provided. The hollow shaft structure is made up of a number of layers of monotape which are assembled together and then HIPed to form a consolidated composite tubular shaft structure. The monotapes employed in forming the individual layers are prepared by plasma spray deposition of matrix metal onto and around an aligned set of reinforcing filaments. Following the plasma spray deposition of the matrix metal, the upper portion of the metal is removed by grinding or machining to increase the density of the monotape by removing the lens dense upper layer. The monotapes are assembled into the hollow shaft configuration by wrapping onto a shaft shaped mandrel in successive layers wound at a pitch to the axis of the mandrel. Consolidation of the multilayer wound structure is accomplished by HIPing at at least 900.degree. C. and at least 15 ksi for a period of more than 1 hour.

Abstract: A method for improved HIPing of filament reinforced metal matrix composite samples is disclosed. The method departs from conventional HIPing practice in that it does not rely on the heating of the HIPing gas in order to increase pressure. Rather, the temperature of the article and of the HIPing gas is first to the HIPing temperature and the pressure of the gas and the pressure on the sample is then raised to the HIPing pressure. Benefits are derived in that a lower level of filament fracture results.

Abstract: An RF plasma gun has a metal annular support ring at the gun's nozzle exit port. The ring is conductively mounted to a metal tank containing a substrate to be processed. The substrate is connected to a manipulator which is electrically isolated from the tank. A DC voltage is impressed between the tank, which contains an inert atmosphere at a pressure below that of ambient atmosphere, and the manipulator. The tank is placed at ground potential and the manipulator at a negative potential relative to the tank. The DC voltage creates an electric arc which flows from the exit port ring via the plasma to the substrate for cleaning the substrate.

Abstract: A method of forming a generally planar part for a jet engine is provided. The part is adapted for withstanding high thermal stress but not high mechanical stress. A preformed strip of a superalloy is mounted around a drum shaped mandrel. A low pressure plasma deposit of a different superalloy is formed on the preformed strip. The strip is demounted and mechanically straightened.