摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A high-temperature, high-strength, oxidation-resistant cobalt-nickel base alloy is disclosed. The alloy includes, in weight percent: about 3.5 to about 4.9% of Al, about 12.2 to about 16.0% of W, about 24.5 to about 32.0% Ni, about 6.5% to about 10.0% Cr, about 5.9% to about 11.0% Ta, and the balance Co and incidental impurities. A method of making an article having high-temperature strength, cyclic oxidation resistance and corrosion resistance is disclosed. The method includes forming a high-temperature, high-strength, oxidation-resistant cobalt-nickel base alloy as described herein; forming an article from the alloy; solution-treating the alloy by a solution heat treatment; and aging the alloy by providing at least one aging heat treatment at an aging temperature that is less than the gamma-prime solvus temperature, wherein the alloy is configured to form a continuous, protective, adherent oxide layer on an alloy surface upon exposure to a high-temperature oxidizing environment.
摘要:
A solid oxide fuel cell comprises at least one hollow manifold, an anode, an electrolyte, and a cathode. The at least one hollow manifold comprises a wall that defines a chamber therein. A plurality of openings extending through, such that the plurality of openings are in flow communication with the chamber. The anode is formed on an exterior surface of the wall. The electrolyte is deposited on the anode, and the cathode is deposited on the electrolyte.