Philip Morris Inc.

Chrysalis Technologies Incorporated

Ametek, Specialty Metal Products Division

Philip Morris USA Inc.

Clive Scorey

Seetharama C Deevi

Vinod Kumar Sikka

Mohammad R Hajaligol

A Clifton Lilly, Jr

Randall M German

Firooz Rasouli

Grier S Fleischhauer

John F Cunningham

Grier Fleishhauer

John McKernan

Methods of producing atomized intermetallic aluminide powders with a controlled oxygen content, and articles made from the powders by powder metallurgical techniques are disclosed. Gas atomized intermetallic aluminide powders can be oxidized to increase their oxygen content. Water atomized intermetallic aluminide powders can be milled to change their size, shape and/or oxygen content. Blends or mixtures of modified gas and water atomized intermetallic aluminide powders can be processed into articles by powder metallurgical techniques.

Methods for modifying oxygen content of atomized intermetallic aluminide powders and for forming articles from the modified powders

A method of cold fabricating an intermetallic alloy composition, comprising steps of coating an article of an intermetallic alloy composition with a viscous medium which provides a moisture resistant barrier on the surface of the article, fabricating the coated article into a desired shape, and optionally removing the coating from the shaped article. The coating step can be carried out by applying oil to the surface of the article or immersing the article in oil. The intermetallic article can be an iron aluminide and the fabrication step can include stamping, bending, drawing, forming, cutting, shearing or punching. During the fabrication step a surface oxide film is cracked and metal surfaces exposed by the cracked oxide film are protected from exposure to moisture in the air by the viscous medium.

Method of minimizing environmental effect in aluminides

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as &lE;1% Cr, &gE;0.05% Zr &lE;2% Ti, &lE;2% Mo, &lE;1% Ni, &lE;0.75% C, &lE;0.1% B, &lE;1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, &lE;1% rare earth metal, and/or &lE;3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 &mgr;m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Method of manufacturing aluminide sheet by thermomechanical processing of aluminide powders

Thermomechanical processing of plasma sprayed intermetallic sheets

A powder metallurgical process of preparing a sheet from a powder having an intermetallic alloy composition such as an iron, nickel or titanium aluminide. The sheet can be manufactured into electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 4 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.0.05% Zr.ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Ni, .ltoreq.0.75% C, .ltoreq.0.1% B, .ltoreq.1% submicron oxide particles and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, and/or .ltoreq.3% Cu. The process includes forming a non-densified metal sheet by consolidating a powder having an intermetallic alloy composition such as by roll compaction, tape casting or plasma spraying, forming a cold rolled sheet by cold rolling the non-densified metal sheet so as to increase the density and reduce the thickness thereof and annealing the cold rolled sheet. The powder can be a water, polymer or gas atomized powder which is subjecting to sieving and/or blending with a binder prior to the consolidation step. After the consolidation step, the sheet can be partially sintered. The cold rolling and/or annealing steps can be repeated to achieve the desired sheet thickness and properties. The annealing can be carried out in a vacuum furnace with a vacuum or inert atmosphere. During final annealing, the cold rolled sheet recrystallizes to an average grain size of about 10 to 30 .mu.m. Final stress relief annealing can be carried out in the B2 phase temperature range.

Method of manufacturing aluminide sheet by thermomechanical processing

The present invention relates to a process for making an aluminum silicon carbide composite material in strip form. The process comprises blending a powdered aluminum matrix material and a powdered silicon carbide material, roll compacting the blended powdered materials in an inert atmosphere to form a green strip having a first thickness, and directly hot working the blended and roll compacted materials to bond the aluminum matrix material particles and the silicon carbide particles and to form a thin strip material having a desired thickness.

Aluminum-silicon carbide composite and process for making the same

The present invention relates to a copper-molybdenum composite material having utility in electrical applica- tions and the process for forming the composite material. The composite material is characterized by a continuous copper matrix having a plurality of discrete molybdenum particles embedded therein. The molybdenum particles have an aspect ratio in the range of from about 1:1 to about 4:1 so as to create a thermal path through the matrix from a first side of the composite material to a second side of the composite material. The resulting composite material exhibits improved through-thickness thermal conductivity as a result of the molybdenum particles being within the aforementioned range. The process for forming the composite material includes the steps of blending the molybdenum in powder form with powdered cuprous oxide, heating the blended powdered material to form copper-coated molybdenum particles, blending the copper-coated molybdenum particles with powdered copper and then roll compacting the blended materials to form the composite material. For certain compositions, i.e., those where the molybdenum content is greater than 80 wt. %, the second blending step may be omitted.

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Cheshire, CT, United States of America

Clive Scorey