Abstract: A composite grained cast article is provided from a superalloy casting in the single grained condition, in one form, by mechanically working a portion of the article intended to operate at a lower temperature of up to about 1300.degree. F. The mechanically worked portion is then recrystallized by heating to provide a multi-grained portion. In another form, the multi-grained portion is provided by selective use of grain nucleation material during solidification.

Abstract: A method for applying a metallic coating to inner wall surfaces of a fluid-cooled turbomachinery blading member employs a substantially dry coating powder mixture which includes inert filler powder having a nonuniform powder size blend and a coating powder source which reacts with a halide activator to generate a coating vapor. The coating powder mixture is retained within a portion of the blading member during heating to generate the vapor. Blading members can be repaired and fluid-cooling passage exit openings can be resized.

Abstract: A gas turbine engine air cooled blade member which includes a base, an airfoil and a platform therebetween generally extending beyond the airfoil, the airfoil including leading and trailing edge portions at least one of which has an edge chamber extending longitudinally of the airfoil and extending chordwise into the airfoil toward the other edge to a longitudinally extending chamber wall is repaired by removing from the blade member at least one blade segment which comprises an edge portion, a part of the chamber wall, and a part of the platform connected with and extending from the edge portion and connected with the chamber wall. This provides for each edge portion removed a first alignment and bonding surface on the blade member remaining. Such alignment and body surface is cleaned to remove surface oxides.

Abstract: A method for removing scale, particularly oxide scale, from a surface of a high temperature alloy, the surface having been exposed to high temperature conditions, employs an aqueous alkaline hydroxide solution in contact with the scale in an autoclave. The solution is heated in the autoclave in a non-oxidizing atmosphere at a temperature in the range of about 200.degree.-340.degree. C. while providing relative movement between the solution and the scale. Thereafter, the scale reaction product is flushed from the surface to remove the alkaline solution.

Abstract: A high temperature cushion for a low ductility member or article, such as of a ceramic material, comprises a flexible, fibrous core of a resilient, refractory material, and a metal foil of a high temperature material covering the core. The foil has ductility sufficient to be formed about the core, the core and foil being further characterized by the ability to withstand a temperature of at least about 1,000.degree. F. (about 540.degree. C.) Forms of such a cushion include an annular bushing and various shaped holders and interface members. Such a cushion can be included as a part of a high temperature operating article which comprises metal portions functioning as backing or holding members, a low ductility article or member such as of a ceramic material, a high temperature cushion interfacing between the metal portions and the member, and a securing member mechanically joining the metal portion with the low ductility member.

Abstract: An improved columnar grained, polycrystalline, anisotropic article is provided of a Ni-base, carbide fiber reinforced eutectic alloy by a method of providing a unidirectionally solidified cast body which includes such fibers aligned and embedded in a gamma-gamma prime structure. Such body is heated at a first temperature to fully solution the gamma-gamma prime without melting the carbide fibers; exposed to a second, lower, temperature to precipitate fine gamma prime in substantially cuboidal shape within the size range of 1-4 microns; and exposed to a third, still lower, temperature to perfect such cuboidal structure without refinement or coarsening. The resultant article is characterized by improved longitudinal stress rupture life.

Abstract: A gas turbine engine air cooled vane assembly which includes inner and outer platform members and an airfoil member therebetween is repaired by removing from the vane assembly a vane assembly segment comprising at least a portion of the leading edge wall, a portion of the airfoil body wall and a portion of at least one platform member connected with the leading edge wall. The vane assembly segment is removed along a preselected path which, during operation of the vane assembly in a gas turbine engine, experiences relatively low mechanical stresses. A replacement member of substantially the same type of material and of a size and shape which matches the removed vane assembly segment is placed into registry with the vane assembly and then metallurgically bonded to the vane assembly.

Abstract: A turbomachinery blade, which includes an airfoil and a projection from the airfoil for the purpose of abutting contact with the surface of an adjacent member is provided with a surface means having an improved combination of adhesive wear resistance and impact toughness through the attachment to the contact surface of a discreet wear pad. The pad comprises a substantially fully dense, compacted, sintered member of a material selected from carbides, nitrides and borides, with or without a suitable binder, the pad being of a thickness of at least about 0.01 inches and having thermal expansion characteristics compatible with the projection over the range of intended operating temperature.

Abstract: The hot isostatic pressure (HIP) method for densification of a metal casting which includes surface-connected discontinuities over which a coating is applied to bridge surface openings associated with the discontinuities and to prevent pressurizing fluid penetration within such discontinuities is improved through the application of a selected type of ceramic coating. Such coating is of a material which provides a substantially gas impervious ceramic coating, preferably of a thickness in the range of about 0.003-0.01", having a coefficient of thermal expansion matched with that of the casting surface to which it is applied as well as having the property of being viscous under the densification processing conditions at which the bond between the coating and the casting surface degrades. Upon cooling, the coating is easily removed from the surface of the densified casting.

Abstract: A property, such as ductility, mechanical strength and increased remelt temperature, of an alloy, for example one which includes an element such as Si or B, or both, is improved by depletion of such an element through the alloy surface. This is accomplished by exposing the alloy surface, one common form of which is a brazing alloy, to gaseous ions such as fluoride ions, while heating the alloy at a temperature which is not detrimental to the alloy or members associated with the alloy. Heating is conducted for a time sufficient for such elements, for example those selected from Si and B, included as a melting point depressant, to diffuse to the surface of the alloy and to react with the gaseous ions to form a gaseous compound of the element. Such gaseous compound then separates from the surface, thereby depleting the alloy of the element and improving at least one property.

Abstract: A turbomachinery blade including a hollow interior is provided with an improved tip cap comprising first and second members each made of an alloy of a composition and properties different from the other. The first member, in the form of a closure plate bonded to sidewalls of the hollow body, is of a nickel-base or cobalt-base superalloy casting characterized by high mechanical strength properties at elevated temperatures. The second member is a rib of the shape of and bonded to the first member and is of a cast alloy characterized by the combination of resistance to oxidation, sulfidation and thermal fatigue at elevated temperatures. The second member provides an outer tip extension of the blade.

Abstract: An improved gas seal between a stationary member and a movable member, one of which includes an abrasive tipped projection directed toward a surface of the other, for example a turbine engine blade and a cooperating shroud member, is provided through an improvement in the abrasive tip. Such improved tip of the projection is a composite of inner and outer tip portions, the inner portion comprising an alloy resistant to oxidation, sulfidation and thermal fatigue at operating temperatures and the outer tip portion comprising a matrix entrapping a plurality of abrasive particles which protrude from the matrix toward the surface of the other member. The inner tip portion is bonded with the metallic body of the projection and the outer tip portion is deposited on the inner tip portion.

Abstract: An improved gas seal between a stationary member and a movable member, one of which includes an abrasive tipped projection directed toward a surface of the other, for example a turbine engine blade and a cooperating shroud member, is provided through an improvement in the abrasive tip. Such improved tip of the projection is a composite of inner and outer tip portions, the inner portion comprising an alloy resistant to oxidation, sulfidation and thermal fatigue at operating temperatures and the outer tip portion comprising a matrix entrapping a plurality of abrasive particles which protrude from the matrix toward the surface of the other member. The inner tip portion is bonded with the metallic body of the projection and the outer tip portion is deposited on the inner tip portion.

Abstract: A turbomachinery blade including a hollow interior is provided with an improved tip cap comprising first and second members each made of an alloy of a composition and properties different from the other. The first member, in the form of a closure plate bonded to sidewalls of the hollow body, is of a nickel-base or cobalt-base superalloy casting characterized by high mechanical strength properties at elevated temperatures. The second member is a rib of the shape of and bonded to the first member and is of a cast alloy characterized by the combination of resistance to oxidation, sulfidation and thermal fatigue at elevated temperatures. The second member provides an outer tip extension of the blade.

Abstract: An improved lightweight composite article comprises a base portion and a spaced apart cap portion between which is secured a body portion comprising a plurality of thin metallic ribbons secured between the base portion and cap portion. The ribbons are disposed in substantially unbonded, aligned relationship at an upper wall portion which is integral with the cap portion formed from top edge extensions of the ribbons. The cap portion is disposed angularly to the body portion to provide one boundary of interstices defined within the member. Such a lightweight, porous-type member can be provided with a relatively smooth, substantially continuous surface through the rubbing or smearing of portions of the member surface with a smooth, relatively hard moving rubbing surface such as the peripheral smooth rim surface of a rotating wheel.

Abstract: The inspection of a portion of an internal member of an assembled article, unavailable for direct line inspection, for example portions of the rotor of a gas turbine engine, is accomplished through the use of an ultrasonic probe inserted through an access port of the article toward a surface of the member to be inspected. As a result of predetermined positioning of a transducer in the operating head of the probe to bounce an ultrasonic signal from an internal boundary toward the portion to be inspected and the comparison between predetermined and received signals, along with an analysis of the comparison, determines whether a defect is present in the member.

Abstract: A directional solidification melting and self-casting apparatus is improved through the provision of a multi-zoned, self-casting furnace including the combination of an induction heated, insitu charge melting upper zone and a resistance heated lower zone.

Abstract: A cast nickel-base alloy article having a complex internal passage and a columnar grain structure is provided with an improved combination of castability and mechanical properties through a control of the amount of gamma prime phase and its related phase formers, a careful control of Co and Al along with Hf and a control of the gamma solution strengtheners, particularly Mo and W.

Abstract: An improved Ni-Co-Cr base casting alloy is particularly useful as a directionally solidified article in the form of a gas turbine blade tip portion to provide resistance to the combination of oxidation, sulfidation and thermal fatigue at elevated temperatures. The alloy base is enhanced through the alloying additions of Ta, Al, W, C, Si and optionally La.

Abstract: An improved gas seal between a stationary member and a movable member, one of which includes an abrasive tipped projection directed toward a surface of the other, for example a turbine engine blade and a cooperating shroud member, is provided through an improvement in the abrasive tip. Such improved tip of the projection is a composite of inner and outer tip portions, the inner portion comprising an alloy resistant to oxidation, sulfidation and thermal fatigue at operating temperatures and the outer tip portion comprising a matrix entrapping a plurality of abrasive particles which protrude from the matrix toward the surface of the other member. The inner tip portion is bonded with the metallic body of the projection and the outer tip portion is deposited on the inner tip portion.