United Technologies Corporation

Teledyne Industries, Inc.

Daniel F Paulonis

David S Duvall

Paul D Genereux

Robert P Schaefer

William A Owczarski

James Thompson Beals

Dilip M Shah

Daniel A Bales

Carl R Verner

Dinesh K Gupta

Keith A Santeler

Sudhangshu Bose

Joseph F Loersch

Stephen Douglas Murray

John J Marcin

Joshua E Persky

Glenn A Cotnoir

Jacob A Snyder

David R Malley

Martin J Blackburn

John A Miller

John D Wiedemer

Harvey R Toppen

Edgar E Brown

Jeffery W Samuelson

Laurence A Jackman

Frederick P Vaccaro

Gerard Casimer Sikorowicz

William M Thomas

O Preston Lowrey, Jr

Venkat Seetharaman

Robert H Caless

Anne L D'Orvilliers

Stephen D Murray

Keith Santeler

A refractory metal core for use in a casting system has a coating for providing oxidation resistance during shell fire and protection against reaction/dissolution during casting. In a first embodiment, the coating includes at least one oxide and a silicon containing material. In a second embodiment, the coating includes an oxide selected from the group of calcia, magnesia, alumina, zirconia, chromia, yttria, silica, hafnia, and mixtures thereof. In a third embodiment, the coating includes a nitride selected from the group of silicon nitride, sialon, titanium nitride, and mixtures thereof. Other coating embodiments are described in the disclosure.

Refractory metal core coatings

A process for producing a fine grain forged superalloy article having a high yield strength at intermediate temperatures. A preferred starting composition comprises, by weight, 15% Cr, 13.6% Co, 4.1% Mo, 4.6% Ti, 2.2% Al, 0.01% C, 0.007% B, 0.07% Zr, balance Ni. This material is forged at a temperature above the gamma prime solvus and at a true strain of at least 0.5. Alternately, the material may be forged below the gamma prime solvus temperature with intermediate super solvus anneals. The overaged material is then worked at a temperature below the gamma prime solvus. The resultant fine grain material is then heat treated or can be further isothermally forged prior to heat treatment to produce complex shapes.

Superalloy forging process

Heat treatments are described for improving the fatigue properties of superalloy articles, without adversely affecting other mechanical properties. The entire heat treatment process is performed below the gamma prime solvus temperature so that significant grain growth does not occur. The heat treatment cycle causes the formation of gamma prime particles in a controlled manner and morphology, first at the grain boundaries and then within the grains. The resultant microstructure possesses the benefits of a fine grain structure (improved resistance to fatigue crack initiation) and fine gamma prime particle size (improved resistance to crack growth).

Heat treatment for improving fatigue properties of superalloy articles

A process is described for converting a fine grain superalloy casting into a forging having mechanical properties equivalent to those resulting from powder metallurgy processing. Cast material is extruded and forged. A HIP treatment is employed to close porosity.

Nickel base superalloy articles and method for making

Forging processes are described for cast superalloys. The forgeability of superalloy materials is improved by the development of overaged microstructure. The total forging process is usually performed in a series of steps with intervening heat treatments to reform the overaged microstructure.

Forging process for superalloys

Methods for increasing the forgeability of cast superalloy materials are described. An extremely overaged microstructure is developed by solutionizing the material and slow cooling in the vicinity of the solvus temperature to cause a precipitation of extremely coarse gamma prime material. Subsequently the material can be isothermally forged.

Nickle base superalloy articles and method for making

An interlayer for transient liquid phase diffusion bonding of the nickel, cobalt and iron alloys is provided between surfaces to be joined as a thin lamellar composite.

Method of making a composite interlayer for diffusion bonding

An improved diffusion bonding fixture for holding workpiece surfaces in opposed contacting relation and exerting controlled pressure across the surfaces is disclosed. The fixture includes components having different thermal expansion characteristics which hold the workpiece surfaces together and generate pressure on the surfaces upon heating to the bonding temperature. The fixture also includes one or more pressure-controlling shim members disposed between the components of the fixture, the shim members being selectively and controllably deformed by the expanding components to control said bonding pressure at the desired value and to prevent unwanted distortion of the workpiece surfaces and fixture components. The fixture is especially useful in bonding workpiece surfaces of highly complex configurations, such as those associated with gas turbine blades, vanes and the like.

Controlled-pressure diffusion bonding and fixture therefor

In filling voids in or between metallic articles, as in the repair of cracks or other surface defects in castings, the void is filled with a powder mix which upon heat treatment fills the void. The filler powder mix is a blend of at least two distinct powder components and in terms of overall composition preferably corresponds to that of article being repaired. The components comprising the mix are selected to provide a transient liquid phase and isothermal resolidification of a portion of the mix at the temperature below the article melting point. A subsequent heat treatment is preferably utilized for homogenization.

Metallic filler material

Composite interlayer for diffusion bonding

Method of repairing surface defects using metallic filler material

A reduced melting point interlayer for transient liquid phase diffusion bonding of the nickel, cobalt and iron alloys is provided as a thin coating integral with one or more of the surfaces to be joined.

Interlayer for transient liquid phase diffusion bonding

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Higganum, CT, United States of America

Daniel F Paulonis