United States of America As Represented by the Secretary of the Air Force

Systems Research Laboratories

Steven J Savage

Daniel Eylon

Francis H Froes

Setumadhavan Krishnamurthy

Erica Robertson

Franz J Hehmann

C Edward Harper, Jr

System and method for producing metal or alloy powder are described which comprises a housing defining a cylindrical chamber having an inlet and an outlet and a plurality of passageways in the form of fluid nozzles defined through the housing wall along axes oriented at preselected angle to the chamber wall, the passageways being operatively connected to a pressurized source of fluid so that fluid is injected into the chamber as fluid jets of preselected flow rate and is swirled in controllable helical fashion generally toward the chamber outlet, and a molten source of metal or alloy operatively connected through a molten metal nozzle and atomization die to the inlet of the chamber for directing molten particles into contact with the fluid jets for solidification and cooling along downward helical paths within the chamber. A plurality of concentric annular bins may be disposed near the outlet of the chamber for collecting powder formed within the chamber.

System for making centrifugally cooling metal powders

System and method for producing metal or alloy powder are described which mprises a housing defining a cylindrical chamber having an inlet and an outlet and a plurality of passageways in the form of fluid nozzles defined through the housing wall along axes oriented at preselected angle to the chamber wall, the passageways being operatively connected to a pressurized source of fluid so that fluid is injected into the chamber as fluid jets of preselected flow rate and is swirled in controllable helical fashion generally toward the chamber outlet, and a molten source of metal or alloy operatively connected through a molten metal nozzle and atomization die to the inlet of the chamber for directing molten particles into contact with the fluid jets for solidification and cooling along downward helical paths within the chamber. A plurality of concentric annular bins may be disposed near the outlet of the chamber for collecting powder formed within the chamber.

Method for making centrifugally cooled powders

A novel magnesium alloy consisting essentially of about 6 to 14 weight percent calcium, about 4 to 8 weight percent of copper or nickel, balance magnesium. There is also provided a process for producing a magnesium alloy article having improved properties which comprises the steps of providing a rapidly solidified product having the composition defined above and having a maximum average thickness of about 200 microns in at least one dimension, introducing the rapidly solidified product into a mold, and consolidating the rapidly solidified product to obtain a desired densification of the rapidly solidified product. Consolidation may be carried out by hot isostatic pressing (HIP'ing) the rapidly solidified product at a pressure of about 100 to 300 MPa and a temperature of about 150.degree. to 350.degree. C. for a time sufficient to obtain the desired densification. Alternatively, consolidation may be accomplished by extrusion using the same temperature range, and an extrusion ratio of about 10:1 to 30:1.

Magnesium-calcium-nickel/copper alloys and articles

System and method for producing metal or alloy powder are described comprising an electromagnetic levitating coil having an outlet for supporting a molten source of the metal or alloy and controllably discharging a molten stream thereof, an electromagnetic confining coil disposed at the outlet of the levitating coil and surrounding the molten stream for controlling the diameter of the molten stream, and either an atomization die and associated pressurized fluid source for disintergrating the confined molten stream into molten droplets for subsequent cooling to powder, or a controllable electromagnetic coil surrounding the confined molten stream for generating a downwardly and radially outwardly directed electromagnetic force interacting with the molten stream to form the droplets.

Method for making rapidly solidified powder

Powders, and particularly metallic powders, are produced by electro-discharge machining of electrically conductive electrodes made of the desired materials in a cryogenic dielectric. When a sufficient quantity of powder has been produced, the cryogenic dielectric is allowed to evaporate, leaving the powders available for recovery. Powders formed by this process have unique microstructures, and thus unique properties, as a result of rapid cooling in the cryogenic medium. By using an inert cryogenic dielectric, such as argon, powders uncontaminated by the dielectric are produced.

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Farsta, Sweden

Steven J Savage