Abstract: An airfoil for an internal combustion engine, such as a gas turbine, formed by use of a preform. The airfoil includes: an outer surface forming the foil shape; and a plurality of craze-free cooling passages extending through the airfoil. In the preferred embodiment, a root on the airfoil joins the airfoil to the hub of a gas turbine vane assembly. Also, in the preferred embodiment, the gas turbine vane assembly is adapted to receive replaceable airfoils.

Abstract: A titanium article for an ultrasonic inspection is provided in which the titanium article can be ultrasonic inspected for determining its acceptability in for microstructurally sensitive applications. The ultrasonic inspection method comprises providing a titanium article, directing ultrasonic energy of ultrasonic inspection to the titanium article; scattering reflected energy in the titanium article; determining an amount of noise generated by the ultrasonic inspection of the titanium article; and characterizing the titanium article as acceptable if the amount of noise as a function of ultrasonic frequency or wavelength is characteristic of predominantly Rayleigh scattering and the magnitude of the noise is less than a pre-determined noise level. The titanium article comprises an uniform-fine grain microstructure. The uniform-fine grain microstructure generates predominantly Rayleigh scattering when undergoing ultrasonic inspection. The invention also sets forth a method of forming a titanium article.

Abstract: A ceramic casting shell mold having a pre-selected shape comprises alternate, repeating layers of a ceramic coating material and a ceramic stucco, defining a total thickness of the shell mold; and a ceramic-based reinforcing sheet disposed in the alternate, repeating layers of coating material and stucco at an intermediate thickness. The ceramic-based reinforcing sheet comprises a one-piece monolithic, integral body, which comprises a pattern of holes that enhance bonding between the ceramic-based reinforcing sheet and adjacent ones of the alternate, repeating layers of ceramic coating material. The ceramic-based reinforcing sheet conforms to the shape of the mold and providing structural reinforcement to the mold.

Abstract: An ultrasonic inspection method for inspecting titanium material is provided. The ultrasonic inspection method is capable of detecting critical flaws in the titanium material that may limit titanium material applications.

Abstract: A method for inspecting a titanium-based alloy that comprises alpha phase grains to detect flaws in the titanium-based alloy, the titanium-based alloy comprises an alpha phase that is provided by thermomechanically processing the alloy to provide a microstructure which comprises the alpha phase that defines an average grain size and a crystallographic orientation of the grains of the alpha phase that is highly randomized. The method comprises ultrasonically inspecting the titanium-based alloy using an ultrasonic beam, the ultrasonic beam comprising a cross-sectional area that is less than the average grain size of the alpha phase in the titanium-based alloy; and determining flaws based on the step of ultrasonic inspecting.

Abstract: An ultrasonic inspection method for determining acceptability of material for microstructurally sensitive applications comprises providing a material, directing ultrasonic energy of ultrasonic inspection to the material; scattering reflected energy in the material; determining an amount of noise generated by the ultrasonic inspection; and characterizing the material as acceptable if the amount of noise corresponds to a pre-determined noise level. The invention also sets forth a system for implementing the method, as embodied by the invention.

Abstract: A method is set forth for processing titanium and titanium alloys into titanium articles, in which the titanium exhibits enhanced ultrasonic inspection results for determining its acceptability in microstructurally sensitive titanium applications. The method for processing titanium comprises providing titanium at a temperature above its &bgr;-transus temperature; quenching the titanium from a temperature above the &bgr;-transus temperature, the step of quenching titanium forming an &agr;-plate microstructure in the titanium; and deforming the quenched titanium into a titanium article, the step of deforming the quenched titanium transforming the &agr;-plate microstructure into discontinuous &agr; particles without crystallization textures. The discontinuous-randomly textured &agr; particles lead to a reduction in ultrasonic noise during ultrasonic inspection.

Abstract: A titanium article for an ultrasonic inspection is provided in which the titanium article can be ultrasonic inspected for determining its acceptability in for microstructurally sensitive applications. The ultrasonic inspection method comprises providing a titanium article, directing ultrasonic energy of ultrasonic inspection to the titanium article; scattering reflected energy in the titanium article; determining an amount of noise generated by the ultrasonic inspection of the titanium article; and characterizing the titanium article as acceptable if the amount of noise as a function of ultrasonic frequency or wavelength is characteristic of predominantly Rayleigh scattering and the magnitude of the noise is less than a pre-determined noise level. The titanium article comprises an uniform-fine grain microstructure. The uniform-fine grain microstructure generates predominantly Rayleigh scattering when undergoing ultrasonic inspection. The invention also sets forth a method of forming a titanium article.

Abstract: A grain starter capable of nucleating a multiplicity of grains in a casting is positioned within a mold. The mold is filled with molten metal and a solidification interface is caused to pass from the grain starter through the molten metal by immersing the mold in a cooling bath to form a casting that has a multiplicity of grains nucleated by the grain starter.

Abstract: A continuously-graded bond coat comprises a gradient of at least one material characteristic value. The gradient extends from a first material characteristic value at a first surface region to a second material characteristic value at a second surface region. The continuously-graded bond coat can be used in a thermal barrier coating system. A source ingot for forming the continuously-graded bond coat comprises aluminum, in an atomic percent range from about 50.0 to less than about 100.0; chromium in an atomic percent range from about 5.0 to about 40.0; silicon in an atomic percent range from about 1.0 to about 17.0; zirconium in an atomic percent range from about a trace to about a 0.5, yttrium in an atomic percent range from a trace to about 2.0; and hafnium in an atomic percent range from about 0.5 to about 2.0. A method for forming the continuously-graded bond coat with the gradient is also provided by the invention.

Abstract: A liquid metal cooled directional solidification process provides improved solidification characteristics at the solidification front. In the process, a mold is filled with molten metal; and a solidification interface is caused to pass through the molten metal by progressively immersing the mold into a cooling liquid. The cooling liquid is a eutectic or near eutectic metal composition. A directional solidification furnace includes a heating furnace, a liquid cooling bath and a mold positioner. The heating furnace has an open bottom end through which a heated mold containing molten metal is lowered from the furnace. The liquid cooling bath comprises a molten eutectic or near eutectic metal composition positioned beneath the open end of the furnace. The mold positioner gradually lowers the heated mold from the furnace, through the open end and immerses the mold into the liquid cooling bath.

Abstract: A cast superalloy article having a unidirectional crystal structure that is substantially defect free with primary dendrite arm spacing greater than 150 &mgr;m is provided. The unidirectional crystalline microstructure comprises a longitudinal columnar structure aligned parallel with the direction of solidification where said columnar structure is a single crystal or polycrystals or mixtures thereof.

Abstract: An apparatus for sorting fragments of titanium-based sponge on the basis of color is disclosed. The apparatus captures at least one color image of each fragment, inserts relevant color values from the image into an automated color-sorting system to determine the color of the fragment, and segregates the fragments according to color or range-of-color, by way of a physical segregation apparatus controlled by the color sorting system. The color sorting systems usually involve the conversion of color images from the fragments into color signals, which are in turn transformed into color values. The color images are usually represented by a pattern of pixels. The color values are automatically compared to values, which are part of a look-up table based on data sets, which embrace acceptable or rejectable color values. Comparison of color values determined for the fragments with those in the look-up table results in the acceptance or rejection of each fragment.

Abstract: A bond coat (20) of a thermal barrier coating system for components designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The composition of the bond coat (20) has graded thermal expansion properties that moderate the transition between a metal substrate (10) and a thermal-insulating ceramic layer (12) of a TBC protecting the substrate (10), while also reducing the service temperature of the bond coat (20) so as to reduce its rate of oxidation. Preferably, the bond coat (20) has multiple layers (20a, 20b, 20c), with the coefficients of thermal conductivity of the individual bond coat layers (20a, 20b, 20c) being very close to that of the substrate (10) in order to promote heat transfer from the outward layer (20c) of the bond coat (20) to the substrate (10).

Abstract: A method for sorting fragments of titanium-based sponge on the basis of color is disclosed. The method involves the steps of capturing at least one color image of each fragment, inserting relevant color values from the image into an automated color-sorting system to determine the color of the fragment, and segregating the fragments according to color or range-of-color, by way of a physical segregation apparatus controlled by the color sorting system. A related apparatus for sorting moving fragments of titanium-based sponge on the basis of color is also described.

Abstract: A bond coat of a thermal barrier coating system for components designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The composition of the bond coat has graded thermal expansion properties that moderate the transition between a metal substrate and a thermal-insulating ceramic layer of a TBC protecting the substrate, while also reducing the service temperature of the bond coat so as to reduce its rate of oxidation. Preferably, the bond coat has multiple layers, with the coefficients of thermal conductivity of the individual bond coat layers being very close to that of the substrate in order to promote heat transfer from the outward layer of the bond coat to the substrate. By minimizing the service temperature of the bond coat while grading the thermal expansion properties through the coating system, a more spall-resistant coating system is achieved.

Abstract: Additions of a first alloy constituent of at least one element from the group consisting of Y, Sc, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, or any combinations of them, and a second alloy constituent of at least one element from the group consisting of C, Si, Ge, Sn and Pb, or any combinations of them, to Ti-base alloys can be employed so as to result in an alloy containing an very fine, substantially homogeneous oxide dispersoid of the first constituent, and produce alloys having improved tensile properties, especially tensile elongation. The dispersoid results from the decomposition of an intermediate phase dispersoid comprising a compound of the first and second constituents which results from rapid solidification of the alloy from a melt. It is preferred that the second alloy constituent should be at a concentration sufficient to form the intermediate phase with all of the element or elements comprising the first alloy constituent.