USA as Represented by Secretary of the Navy

James M Kerr

Amarnath P Divecha

William A Ferrando

Subhash D Karmarkar

Scott M Hoover

William A May

William J Bruchey

Gerald Bulmash

A predetermined quantity of a metal-matrix composite material is injected to a heating crucible along an angular infeed direction toward a location therein at which a vortex is formed by the blade of an agitator through which the material is stirred while being superheated above the melting temperature to a pouring temperature under which the melted material is transferred to a casting mold after surface skimming thereof to form a product having improved wear resistance properties.

Fabrication of metal-matrix compositions

Alumina tiles within aluminum framing jigs are fixedly positioned by lock ns within an internally coated mold for centrifugal casting within a block of an aluminum alloy material. Such jigs and the tiles framed therein are coated with silver before casting to prevent aluminum oxidation by heating of the aluminum material to a molten state for deposit into the mold. Bonding of the tiles and framing of the jigs with the aluminum material being cast is also enhanced by such silver coating.

Fabrication of tile reinforced composite armor casting

Silver metal-coated boron carbide (B.sub.4 C) particle reinforce aluminumthium alloy or magnesium-lithium matrix composites which are prepared by coating the B.sub.4 C particles with molten AgNO.sub.3, decomposing the molten AgNO.sub.3 to form a coating of silver metal on the B.sub.4 C particles, mixing the silver coated B.sub.4 C particles into a molten aluminum-lithium alloy or magnesium-lithium alloy matrix, allowing the mixture to cool and solidify the solid composite.

Metal matrices reinforced with silver coated boron carbide particles

A process for producing a superconductor wire by:

Method of producing high temperature superconductor wires

A process for forming pressure cast alumina tile reinforced aluminum alloy rmor in which a silver coated aluminum disc is first inserted into a mold assembly, the mold assembly includes a base plate, a hollow steel die with a removable steel liner located on the base plate, a plug disposed on the base plate within the die cavity, and a punch movably disposed within the die cavity, the aluminum disc being inserted within the die cavity over the plug. Next, an alumina tile preform is prepared by cutting a plurality of alumina tiles and weaving the tiles together with a stiff steel wire. The alumina tile preform is inserted over the silver coated aluminum disc in the cavity of mold assembly. The steel die, the plug and the disc are heated. The punch is also heated separately. A melt of molten aluminum is prepared and poured into the die cavity, completely covering the alumina tile preform. The heated punch is immediately driven into the cavity to apply pressure to the molten aluminum. When the mold assembly cools, the punch is retracted, the base plate is removed, and the composite billet of pressure cast alumina tile reinforced aluminum alloy armor is removed from the mold.

Pressure cast alumina tile reinforced aluminum alloy armor and process

A Nb-Ti or Nb-Zr low temperature superconducting (LTS) wire is coat with ten AgN0.sub.3 which is then decomposed to form a uniform silver metal (Ag) coating on the LTS wire. A uniform coating of molten Al or Al alloy is formed on the Ag coated LTS wire and then solidified. A bundle of the coated LTS wires is inserted into an Al or Al alloy tube and cold worked to form a multifilamentary LTS cable comprising the Ag coated LTS wires each surrounded by an Al or Al alloy matrix.

Multifilamentary superconducting cable and a method of manufacturing it

A high temperature superconducting wire or yarn has a first layer thereon yttria, a third layer of barium cuprate, and a second layer of a superconducting YBa.sub.2 Cu.sub.3 O.sub.7-x formed at the interface between the first and third layers. The wire can be yttrium and the yarn can be alumina.

Superconducting fibers made with yttrium and yttrium oxide interlayers

A reaction vessel comprising (1) a porous ceramic structure having intercecting, open pores and (2) silver metal coating the inner ceramic surfaces of the reaction vessel and filling the interconnecting, open pores to form a strong bond between the porous ceramic structure and the silver coating. The reaction vessel can be produced by

Silver lined ceramic vessel

Process for the production of ingots of castable discontinuous metal matrix omposites by encapsulating particulate refractory material of the B.sub.4 C or SiC in a matrix metal of Li or al to form a solid master alloy, and introducing the master alloy into molten Mg or an alloy thereof, mixing and then cooling to solidify the resultant mixture and form an ingot with the refractory material substantially dispersed in the ingot.

Growing community of inventors

Bethesda, MD, United States of America

James M Kerr