Abstract: A freeze-forging method for producing sintered three-dimensional ceramic bodies, particularly magnesium aluminate spinel domes. The method comprises forming a ceramic mix of a ready-to-sinter ceramic powder and a nonaqueous liquefied sublimable vehicle having a solidification temperature from room temperature to below 200° C.; reducing the temperature of the ceramic mix to below the vehicle's solidification temperature to freeze the mix; crushing the frozen mix into powdered form; molding the frozen powder into net shape by cold forging in a mold to form a net-shaped green body preform of the desired three-dimensional shape; and densifying the green body into a sintered three-dimensional ceramic body.

Abstract: A freeze-forging method for producing sintered three-dimensional ceramic bodies, particularly magnesium aluminate spinel domes. The method comprises forming a ceramic mix of a ready-to-sinter ceramic powder and a nonaqueous liquefied sublimable vehicle having a solidification temperature from room temperature to below 200° C.; reducing the temperature of the ceramic mix to below the vehicle's solidification temperature to freeze the mix; crushing the frozen mix into powdered form; molding the frozen powder into net shape by cold forging in a mold to form a net-shaped green body preform of the desired three-dimensional shape; and densifying the green body into a sintered three-dimensional ceramic body.

Abstract: An in-situ method for nanomixing magnesium aluminate spinel nanoparticles with a uniformly distributed controlled concentration of nanoparticles of an inorganic sintering aid, such as LiF, to produce ready-to-sinter spinel powder. The spinel-sintering aid nanomixture is formed by induced precipitation of the sintering aid nanoparticles from a dispersion of the spinel nanoparticles in an aqueous solution of the sintering aid, followed by separation, drying and deagglomeration of the spinel-sintering aid nanomixed product.

Abstract: A high thermal conductivity metal/diamond metal matrix composite made from diamond particles having thin layers of beta-SiC chemically bonded to the surfaces thereof, is utilized in combination with a machinable metal/carbonaceous material metal matrix composite in an integral metal matrix composite compound structure, to provide a machinable high thermal conductivity heat-dissipating substrate for electronic devices.

Abstract: A freeze-forging method for producing sintered three-dimensional ceramic bodies, particularly magnesium aluminate spinel domes. The method comprises forming a ceramic mix of a ready-to-sinter ceramic powder and a nonaqueous liquefied sublimable vehicle having a solidification temperature from room temperature to below 200° C.; reducing the temperature of the ceramic mix to below the vehicle's solidification temperature to freeze the mix; crushing the frozen mix into powdered form; cold forging the frozen powder in a mold to form a solidified green body of the desired three-dimensional shape; and densifying the green body into a sintered three-dimensional ceramic body.

Abstract: An in-situ method for nanomixing magnesium aluminate spinel nanoparticles with a uniformly distributed controlled concentration of nanoparticles of an inorganic sintering aid, such as LiF, to produce ready-to-sinter spinel powder. The spinel-sintering aid nanomixture is formed by induced precipitation of the sintering aid nanoparticles from a dispersion of the spinel nanoparticles in an aqueous solution of the sintering aid, followed by separation, drying and deagglomeration of the spinel-sintering aid nanomixed product.

Abstract: The microstructure of a metal matrix composite comprising copper and reinforcement material is improved when the metal matrix composite comprises at least about 0.02% by weight of at least one of silver and gold. In one embodiment, the process for making a metal matrix composite comprises compacting powder particles of a reinforcement material to form a green compact, sintering the green compact to produce a porous skeletal body and infiltrating the porous skeletal body with an infiltrant comprising copper and at least about 0.1% of at least one of silver and gold, based on the weight of infiltrant. In another embodiment, the process comprises forming a mixture of particles of reinforcement material, copper and at least about 0.02% by weight of at least one of silver and gold, compacting the mixture to form a green compact, and sintering the green compact to form a near net shape metal matrix composite.

Abstract: The thermal conductivity, thermal conductivity, of a sintered copper/refractory metal composite having a maximum porosity of about 1% is greatly improved when the composite contains phosphorus and sintering aid in a specified weight ratio, “phosphorus/sintering aid ratio.” The copper/refractory matrix composite herein comprises, by weight, from about 5% to about 30% copper, from about 0.2% to about 0.6% sintering aid, from about 0.08% to about 0.3% phosphorus, the remaining metal is refractory metal. The phosphorus to sintering aid ratio ranges from about 0.25 to about 0.55. In one embodiment of the invention the sintering aid contains cobalt and the refractory metal is tungsten.

Abstract: A carrier sub-assembly having improved dimensional stability for applications in electronic and optoelectronic industries is disclosed. The carrier sub-assembly, when housed in an optoelectronic package, for example, includes a metal substrate and an insert which support optoelectronic devices that are optically coupled to one another. The insert allows for the attachment, for example, via laser spot welding, of electronic and optoelectronic devices where direct attachment of a device to the metal substrate is not practical. In one embodiment of the present invention, the carrier sub-assembly includes Kovar™ insert that is attached to copper/tungsten metal substrate in a recess of the metal substrate so that at least a portion of the insert is attached to the metal substrate in three dimensions. A fiber optic assembly is secured to the insert by a Kovar™ clip.

Abstract: The present invention provide a plurality of layered substrates for semiconductor packages. The substrates include, for example, a metal matrix composite layer and at least one carrier layer having a coefficient of thermal expansion and a thermal conductivity greater than the metal matrix composite. In the preferred embodiment, the metal matrix composite includes between approximately 50% to 95% refractory metal with the remainder copper. Suitable carrier layer materials include, for example, copper. So configured, the layered substrates provide improved rigidity and thermal characteristics for matching with ceramic materials.

Abstract: The invention provides for a functionally-graded metal substrate that is made of at least two metal compositions, a functional insert and a surrounding body that surrounds the functional insert. In a preferred embodiment of the invention a functional insert powder composition of loose powder metal is placed in a compact of a surrounding body powder composition and both metal compositions are sintered in a sintering furnace to form a sintered part. The sintered part is infiltrated in part or in whole with a molten metal compound to produce a functionally graded metal substrate having a density of at least 90% of theoretical. A heat-generating component such as a chip can be attached to the metal substrate for use in microelectronic packaging. When the functionally-graded metal substrate has two discrete compositions of copper/tungsten the surrounding body which has a CTE that ranges from about 5.6ppm/.degree. C. to about 7 ppm/.degree. C.

Abstract: The process for producing net shape or near net shape metal parts is improved by sintering a compact in a reducing atmosphere where the compact contains a metal and chemically-bound oxygen in the form of a metal oxide, for example, and the chemically-bound oxygen is in an amount sufficient to improve the sintering of the compact. Improved sintering is facilitated when the metal oxide forms a metal/metal oxide eutectic during reduction of the chemically-bound oxygen in a reducing atmosphere during the sintering process. The compact can contain a metal oxide and a solution compound to produce an alloy part, provided the chemically-bound oxygen is present in an amount sufficient to improve sintering. In a preferred embodiment, the compact also contains a reinforcement compound and is sintered to make a metal matrix composite. The resultant density of the near net shape metal parts made by the improved sintering process is preferably about 97% or more of the theoretical density.

Abstract: The sinterability of a copper/tungsten green compact is improved by using copper oxide, tungsten oxide or both as the copper and/or tungsten source. Sinterability is further enhanced by including steam in the sintering atmosphere. Spontaneous combustion of the source powders used to form the sintering compacts can be reduced or eliminated by including corrosion inhibitor in the powders.

Abstract: The sinterability of a copper/tungsten green compact is improved by using copper oxide, tungsten oxide or both as the copper and/or tungsten source. Sinterability is further enhanced by including steam in the sintering atmosphere.