Abstract: A rotor blade is manufactured by making a soft alloy into a blade body with a curved section, joining a hard alloy to the leading edge of the blade body, coating the back side surfaces of the leading and trailing edge portions of the blade by alternately giving at least one coat each of a Ni-Cr-B-Si alloy and WC by spraying and fusing the coats onto the backing surfaces, and then coating the entire front side surface of the blade in the same way.

Abstract: A centripetal turbine rotor has ceramic blades with integral blade roots of arcuate axial section which are clamped axially between two supporting elements mounted on a common shaft so that the ceramic blade roots are maintained in compressive stress along their arcuate, radially inwardly convex, profiles, opposing centrifugal strain in the blade roots.Cooling air may be supplied along axial channels in one hub to an internal chamber within the blade roots and may thence flow outwardly into the gases flowing through the turbine.

Abstract: The method produces an article which has a first zone comprising a nonoxide ceramic material (which materials cannot be soldered or welded) and a second zone comprising a different, softer material such as one which can be soldered or welded to other parts. A transition layer between the zones of the article comprises both materials for bonding the zones together. The method forms the article from powders with heat and pressure.

Abstract: In a turbine rotor assembly wherein ceramic blades are secured to slots provided in the periphery of a metallic rotor disc, a metallic jacket is interposed between each blade root and disc slot, and ceramic potting material is, in turn, interposed between the metallic jacket and the ceramic blade root. The metallic jacket also includes locking means to prevent upstream or downstream axial movement of the blade in the disc slot, with the resulting assembly effectively isolating the ceramic root from high localized loads and permitting a more uniform stress distribution on the critical root load bearing surfaces.

Abstract: A turbine wheel assembly having an improved blade attachment is disclosed. Techniques for increasing the low cycle fatigue life of the components forming the attachment are developed. In one specific embodiment a "fir tree" type attachment includes interlocking root teeth and disk teeth. Correspondingly, grooves accommodate the interlocking teeth. Each groove is contoured in a first region to a first radius and in a second region to a second radius.

Abstract: A bearing for the ceramic rotor of a turbine engine or turbomachine, which consists of an air-supported bearing providing for a lubricating air film between the inner and outer bearing rings at least at the higher operating speeds of the engine. This facilitates operation of the turbine engine or machine under high temperature and rotational speed operating conditions.

Abstract: A ceramic turbine rotor fitted to a metal shaft has an integral shaft stub, extending into the hollow end of the metal shaft, and is resiliently retained therein. In order to prevent relative rotation between the rotor and the shaft during torque transfer, the stub shaft and a clamping and tightening member, within the metal shaft, are provided with interengaging parts. The stub shaft, the clamping member and the hollow metal shaft may be formed with mating, interengaging corrugations and grooves running substantially axially. The stub shaft may alternatively have a polygonal cross section, and the clamping member and the void in the hollow shaft will then have mating, but successively bigger cross sections.

Abstract: A radial turbine wheel for a gas turbine which consists of two parts and more particularly of a first part adjoining the turbine inlet which includes the outer sections of the blades and of a second part leading to the turbine outlet which includes the inner essentially curved section of the blades whereby the two parts are made of materials having different properties.

Abstract: A turbine blade having a root provided with a curvature in its transverse and longitudinal cross sections. The root is receivable within the groove in the outer periphery of an attachment piece and the surface portions defining the groove have curvatures slightly greater than those of the root. A compliant pad can be inserted in the groove between each side of the root, respectively, and the corresponding surface portion of the attachment piece. Initially, the root will have a single point of contact with the adjacent surface portion or the compliant pad; but as the blade rotates, this point of contact becomes a line or surface contact to cause loads to be more uniformly distributed between the root and adjacent surface portions.

Abstract: A method and apparatus for manufacturing a twisted ceramic turbine wheel from an electrically conductive or electrically non-conductive ceramic mass with the aid of spark erosion or of ultrasonic machining and with the aid of profiling tools used therewith which are correspondingly matched to the desired profile shape, by means of which the pressure side and the suction side are to be worked; the two profile surfaces, i.e.

Abstract: Composite ceramic articles formed by integrally assembling a plurality of previously molded constituent members without applying an adhesive to their joints and designed to have a density than higher 98% of the theoretical value, and a flexural strength greater than 50 kg/cm.sup.2 at 1200.degree. C., and a method of producing ceramic articles of particularly complicated shape which comprises the steps of previously molding a plurality of constituent members of complicated shape and later integrally assembling said constituent members without applying an adhesive to their joints.

Abstract: A turbine blade comprised of at least a pair of abutting blade parts with each part having a root coupled to an attachment piece, the latter adapted to be coupled to a turbine rotor. The blade parts can be curved and each blade part may have a hollow space in the region where it abuts the other blade part to reduce the weight of the blade. The blade parts may be spigoted or mated with tongue and groove structure to reduce fluid leakage through the junction between the blade parts.

Abstract: A radial turbine wheel for a gas turbine which consists of two parts and more particularly of a first part adjoining the turbine inlet which includes the outer sections of the blades and of a second part leading to the turbine outlet which includes the inner essentially curved section of the blades whereby the two parts are made of materials having different properties.

Abstract: A rotor-shaft assembly comprising a ceramic turbine rotor, a metal shaft and a metal connector disposed between the rotor and the shaft. The metal connector is fixed to the rotor by some suitable means and coupled with the metal shaft by mutual engagement of teeth provided at the ends of the connector and the shaft.

Abstract: The present invention provides an assembly for mounting a row of ceramic rotor blades in the metal rotor disc of a gas turbine engine. The major components of the assembly comprise a well known ferritic metal rotor disc in which is mounted, in a conventional fir-tree root configuration, a plurality of high temperature metal alloy or super alloy intermediate members forming an annular array thereof and defining "dog-bone" shaped axial grooves in the annular face for receipt of a complementary "dog-bone" or single serration root of a ceramic blade for mounting an annular array of ceramic blades. The root shank portion and the air foil portion of the blade are separated by a platform and centrifugal-force pins are inserted between adjacent platforms to fix the blade against low frequency vibration and to seal the gap therebetween against leakage of the motive fluid into the root area.

Abstract: A class of structural oxidation resistant ceramic base materials are described. The materials consist of an oxide matrix, which is resistant to the transport of oxygen by diffusion, and this matrix contains metallic fibers of a material which develops a stable protective oxide layer. The overall material composition is approximately eutectic so that the fiber-matrix combination can be formed by solidification directly from the melt. Directional solidification may be employed to produce a structure with oriented fibers.

Abstract: A turbine rotor is constructed by attaching ceramic turbine blades to a metallic disk. Each of the ceramic blades has an enlarged base which is mounted within an undercut axial groove on the disk. Cushion pads are provided between the turbine blade base and the undercut portion of the groove. The cushion pads are designed with a different radius of curvature than the disk base and a yield pressure which is less than the allowable surface pressure of the ceramic. The rotor construction results in a design which significantly reduces the possibility of turbine blade damage from stresses during use.

Abstract: This turbine wheel has a plurality of blades radiating from a central hub and is manufactured by a novel method including the steps of assembling a plurality of preformed ceramic or superalloy blades into a ring with foot portions on the blades projecting into the central region of the assembly, filling such central region with powdered ceramic material, such as silicon carbide, or a superalloy material, heating and isostatically pressing, at least the central region, to compact the powdered material around the foot portions into a unitary hub. The blade feet are suitably shaped to provide a precise interlocking engagement between the blades and the unitary hub.

Abstract: Improved attachment structure for connecting ceramic blades to the rotor disk of a gas turbine rotor. The structure includes a plurality of metallic attachment pieces having roots inserted into respective grooves in the outer periphery of the rotor disk. Each attachment piece has an outer peripheral groove for receiving the root of a corresponding turbine blade formed of ceramic material. Specific embodiments of an attachment piece and a blade are disclosed, the blade having a base which engages the outer peripheral face of the corresponding attachment piece. The blade base and the corresponding attachment piece have aligned, spaced grooves at the opposed ends thereof for receiving ceramic plates which cover the adjacent parts of the attachment piece. Certain ends of the ceramic plates define recesses for receiving metallic plates which extend radially of the rotor disk and transmit torque from the blade to the attachment piece and thereby to the rotor disk.

Abstract: A turbine rotor having a number of metallic attachment pieces for coupling a plurality of ceramic blades to a metallic rotor disk. The blades have roots which are received within grooves formed in the attachment pieces. Each attachment piece has passage means therethrough cooperating with passages in the rotor disk for receiving a coolant for cooling the attachment pieces without causing the coolant to contact the ceramic blades. The attachment pieces keep the rotor disk isolated from the hot gases which contact the ceramic blades.

Abstract: An improved rotor for a gas turbine engine wherein the rotor has a plurality of ceramic turbine blades coupled by attachment pieces of high-temperature metal to a rotor disk. Each attachment piece has a root received in a corresponding groove in the outer periphery of the rotor disk. Also, each attachment piece is made to couple a pair of turbine blades to the rotor disk, the attachment piece having a pair of axially spaced, radially extending walls, each wall having a hole therethrough and the holes of the walls being aligned with each other. The roots of the two blades for each attachment piece are positioned between its spaced wall and the roots have cooperating projecting parts which engage each other and form a recess through which a pin extends when the ends of the pin are in the holes of the end walls. The roots of the blades of adjacent attachment pieces abut each other to keep the blades from moving laterally relative to respective attachment pieces.

Abstract: The subject rotor comprises a disklike body having hub and rim sections joined by a web section. The body is cast, molded or otherwise suitably formed of powdered silicon (and a binder, if necessary, to make it retain its shape until finally treated) which is reaction bonded to convert the silicon particles into a unitary mass. During the casting, molding or other forming step, one or more reinforcing rings of hot pressed silicon nitride or other suitable ceramic are embedded in the body. The ceramic selected must be one which will unite with the silicon during the reaction bonding operation to make a unitary mass. The reinforcing ring or rings are located in regions exposed to unusual stress in the use of the rotor to achieve the required strength.

Abstract: A gas impermeable hollow silicon carbide body is formed by slip-casting two separate hollow silicon carbide bodies, the two separate bodies are then cemented together by means of a silicon carbide slip and then the joined pieces are fired at a temperature sufficiently elevated to recrystallize the cast bodies and to form a recrystallized joint between the two pieces, thereafter the body is subjected to a silicon atmosphere to deposit sufficient additional silicon in the body to provide a structure which is essentially impermeable to gases.

Abstract: A thermally highly stressed, cooled component, more particularly, a blade for turbine engines, and a method for manufacturing the blade. A component of the above-mentioned type in which a central supporting core formed of a solid material has connected thereto several short, radially outwardly projecting ridges which, in turn, carry an outer shroud concentrically encompassing the supporting core, and which is made of a through-porous material, whereby the supporting core, ribs, and outer shroud are cast in a single piece.

Abstract: A gas turbine having a rotor including a ceramic turbine wheel and a rotor shaft formed in part of ceramic material, the wheel and ceramic shaft portion being formed as one piece. The ceramic shaft portion extends into a cooler zone of the engine where it is connected to a steel shaft portion. The ceramic shaft portion is supported by a radial bearing, preferably an air bearing. A ceramic disk projects radially from, and is formed as one piece with, the ceramic shaft portion, the disk cooperating with a thrust bearing, preferably an air bearing.

Abstract: A rotor for a gas turbine engine has a wrought superalloy disk with ceramic blades. The rotor is formed by placing ceramic blades in a fixture with their ceramic blade roots extending inwardly and between the upper and lower rims of a disk or disk halves. The facing upper and lower circumferential rims are cut away to provide for the ceramic blade roots. Said disk or disk halves being of a wrought superalloy having a fine grain size microstructure which can be placed in a superplastic condition. A compliant layer material is placed between the ceramic blade roots and the rims of the disk, and the disk and compliant layer are then heated so as to place the disk in a superplastic condition and pressed into intimate contact with the ceramic blade root, and if disk halves are being used, they are bonded together at inner mating surfaces. The rotor is then heat treated to return the disk to its normal condition of high strength and hardness.

Abstract: A turbine rotor construction in which the disk has radially extending tubes on which ceramic blades are slidable, and the centrifugal load on the blades is carried by an external filament wound ring surrounding and engaging the outer ends of the row of blades.

Abstract: A device for the torque-transmissive securing of a disc which is formed of a brittle material, in particular a turbine wheel constituted of a ceramic material, onto a shaft. The disc is centered through the intermediary of two cone pairs with axial prestressing and the torque is transmitted to the shaft through a cylindrical extension of the wheel hub with longitudinal grooves formed on the outer circumference thereof; furthermore transmitted by means of a cylindrical bellshaped cover with symmetrically profiled longitudinal connectors in an inner bore which are conformed to the longitudinal grooves, and finally by rollers located between the concave side edges or slopes and the side walls of the longitudinal grooves in radial and tangential contact therewith, by means of the bell-shaped cover which is rigidly fixed on the shaft.

Abstract: The subject rotor comprises a disklike body having hub and rim sections joined by a web section. The body is cast, molded or otherwise suitably formed of powdered silicon (and a binder, if necessary, to make it retain its shape until finally treated) which is reaction bonded to convert the silicon particles into a unitary mass. During the casting, molding or other forming step, one or more reinforcing rings of hot pressed silicon nitride or other suitable ceramic are embedded in the body. The ceramic selected must be one which will unite with the silicon during the reaction bonding operation to make a unitary mass. The reinforcing ring or rings are located in regions exposed to unusual stress in the use of the rotor to achieve the required strength.

Abstract: A rotor for a gas turbine engine comprises an outer shell formed in hot pressed silicon nitride and having substantially uniform thickness in a direction parallel to the axis about which the rotor is rotatable and a heat resistant insert which can be either graphite or reaction sintered silicon nitride which fills the space within the shell and is attached to the shell. A row of blades which can be either hot pressed or reaction sintered silicon nitride can be attached to the periphery of the rotor by diffusion bonding.

Abstract: This invention is concerned with methods and materials for producing unitary silicon nitride structures by means of joining together at least two silicon based bodies with an intervening mixture of silicon powder and a heat removable liquid binder therefor between the joining faces, mantaining said faces in juxtaposition and slowly heating the assembly in a nitriding atmosphere to remove the liquid binder and to convert the material of said bodies and the intervening silicon powder into a unitary structure.

Abstract: In a rotor assembly, first and second annular discs are axially spaced apart on a rotatable shaft so as to be rotatable with the shaft. A plurality of rotor blades are located between the discs and are angularly spaced around the axis of the shaft, and means urges the discs against the blades so that a root portion of each blade is trapped between the discs with the remainder of the blade projecting from the discs. Each root portion is shaped so as to be non-complementary with the portions of the discs between which it is trapped, and each disc is shaped so as to present to each root portion first and second surfaces which, when the shaft is rotated in use, engage respective spaced regions of the root portion so that the root portion is held against axial movement relative to the shaft and against movement radially outwardly relative to the axis of the shaft.