United Technologies Corporation

The United States of America As Represented by the United States

Franklin D Lemkey

Gerald S Golden

Clyde S Brooks

David D Pearson

Earl R Thompson

James G Morris

Donald L Anton

Frank C Douglas

Irving Machlin

A novel micro-structure developed in a cast austenitic stainless steel alloy and a heat treatment thereof are disclosed. The alloy is based on a multicomponent Fe-Cr-Mn-Mo-Si-Nb-C system consisting of an austenitic iron solid solution (.gamma.) matrix reinforced by finely dispersed carbide phases and a heat treatment to produce the micro-structure. The heat treatment includes a prebraze heat treatment followed by a three stage braze cycle heat treatment.

Heat treatment giving a stable high temperature micro-structure in cast

An improved eutectic superalloy composition is described. The eutectic composition upon solidification forms a gamma matrix, containing a substantial quantity of particles of the gamma prime phase, and containing about 12% by volume of aligned continuous chromium carbide fibers (Cr.sub.3 C.sub.2). Material of this composition is provided with significantly improved mechanical properties and surface stability through the addition of approximately one atomic percent of the material selected from the group consisting of manganese, technetium and rhenium. Directionally solidified articles of this composition have utility as gas turbine engine components.

Eutectic superalloy compositions and articles

A carbide reinforced iron based superalloy material is described. The material consists of an austenitic matrix containing about 30 volume percent aligned M.sub.7 C.sub.3 phase fibers. Fiber alignment is produced by directional solidification. A nominal alloy composition (by weight) is 20% Cr, 10% Mn, 5% Al, 3.2% C. balance iron. The alloys are characterized by the absence of strategic elements, are east to process and have superior mechanical properties to the known prior art, low nickel, iron base superalloys.

M.sub.7 C.sub.3 Reinforced iron base superalloys

This disclosure relates to directionally solidified articles produced from a eutectic alloy in the nickel-aluminum-molybdenum system with tantalum added. The articles have a microstructure consisting of a ductile matrix phase of gamma prime containing a fibrous reinforcing second phase of alpha Mo. The nominal composition of the base alloy is 6.9 weight percent aluminum, 15.2 weight percent tantalum, 18.5 weight percent molybdenum, balance nickel. The directionally solidified alloy articles of the invention are characterized by exceptional mechanical properties combined with good oxidation resistance and reasonable sulfidation resistance at elevated temperatures.

Tantalum modified gamma prime-alpha eutectic alloy

A method for producing a supported skeletal catalyst is described. The starting material is an alloy which consists of an aluminum or silicon matrix containing fine particles of an intermetallic compound between the matrix material and a catalytically active metal. Chemical means are used to convert the matrix material to an oxide ceramic while removing the matrix material from the intermetallic particles.

Process for producing supported skeletal catalytic materials

Photon absorbing surfaces which are effective over a broad band of photon energies are described. These surfaces consist of a two-phase material with a protruding second phase whose dimensions are on the order of microns. Photons are absorbed by multiple reflections within the region of the protruding phase. The surfaces are produced by directional solidification of eutectic compositions to produce aligned second phase microstructures within a metallic matrix. The matrix material is then selectively removed to expose the second phase material.

Photon absorbing surfaces and methods for producing the same

A high ductility, high strength, moderate conductivity aluminum conductor article and process for making the article are described. The article is a conductor of elongated geometry containing a low volume fraction of intermetallic fibers which are aligned parallel with the major axis of the conductor. The surrounding matrix is aluminum of at least commercial purity to which from 0.5 to 1.5% copper has been added. The fabrication process involves the coupled solidification of eutectic and slightly proeutectic compositions to produce a fibrous microstructure, followed by mechanical working. The ductility of the finished article will exceed about 5%. The final properties may be varied by heat treatments. The broad composition is 1.0-2.0% Co, 0.5-1.5% Cu, balance aluminum.

High ductility, high strength aluminum conductor

This disclosure relates to an alloy in the nickel-aluminum-molybdenum system of approximately eutectic composition, and articles made by directional solidification of the alloy. The alloy is preferably directionally solidified to produce an article which has a microstructure consisting of a ductile matrix containing ductile reinforcing fibers. The matrix comprises a continuous microstructure of the gamma nickel solid solution phase, and also preferably contains the gamma prime (Ni.sub.3 Al) intermetallic phase in either precipitate or continuous form. The ductile continuous reinforcing phase consists of alpha molybdenum in fibrous form. The nominal composition of the alloy is 4.6 weight percent aluminum, 35.8 weight percent molybdenum, balance essentially nickel.

Directionally solidified eutectic superalloy articles

Supported fibrous skeletal metal catalysts and methods of producing such catalysts are described. The catalysts are produced by directionally solidifying a eutectic composition to produce a microstructure consisting of oriented intermetallic single crystal fibers in a metallic matrix. Selective means are employed to remove a portion of the matrix to expose a portion of the fibers. Leaching means are employed to preferentially remove one of the atomic species from the exposed intermetallic fiber. The exposed leached fibers are porous, have a high surface area and display catalytic activity, depending upon the starting eutectic composition.

Self supported skeletal metal catalysts and process for producing them

High surface area skeletal metal catalysts and methods of producing such catalysts are described. The production involves solidification of certain eutectic compositions to produce a microstructure of intermetallic fibers in solid solution matrix. The matrix is preferentially removed to provide loose intermetallic fibers which may then be leached to provide a porous structure. Directional solidification is a preferred step in the production process.

Metallic fibrous skeletal catalysts and process for producing them

This disclosure relates to a eutectic alloy, and article made from the alloy, in the nickel-aluminum-molybdenum system which may be directionally solidified to produce a microstructure consisting of a ductile matrix phase of gamma prime or gamma prime/gamma containing a reinforcing fibrous or lamellar refractory metal alpha second phase. The nominal composition of the base alloy is 8 weight percent aluminum, 27 weight percent molybdenum, balance nickel. Minor elemental additions may be made to modify the mechanical properties of the first phase and/or the second phase. The directionally solidified alloy of the invention is characterized by exceptional anisotropic tensile properties, high isotropic ductilities, combined with good oxidation resistance and satisfactory sulfidation resistance at elevated temperatures.

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Glastonbury, CT, United States of America

Franklin D Lemkey