W.c. Heraeus Gmbh

Heraeus Quarschmelze Gmbh

Richard Keilberth

Fritz Aldinger

Waltraud Werdecker

David Francis Lupton

Franz Sperner

Albrecht Bischoff

A rod made of a hard material is inserted into a pipe made of a relatively soft material, and a two-element arrangement having an intermediate size is obtained by hot-rolling and drawing. In these steps, the cross section is reduced by at least 50%. Subsequently, another pipe of the soft material is fitted onto the two-element arrangement, and the so-obtained three-element arrangement is adjusted to its final size by means of hot or cold rolling followed by cold drawing.

Process for the manufacture of a metallic composite wire

A heat conductive ceramic substrate for semiconductor circuits, comprising polycrystalline aluminum nitride of high density containing as an additive boron nitride or oxides of calcium, magnesium, aluminum, titanium, zirconium, chrome, silicon, and/or rare earth metals. The boron nitride additive concentration ranges between 0.1 and 3% by weight, preferably between 0.5 and 2% by weight. The oxide additive concentration ranges between 0.1 and 5% by weight. The substrate has a significantly higher thermal conductivity than aluminum oxide substrates and is more economincal to manufacture than beryllium oxide substrates.

Combination of AlN-Y.sub.2 O.sub.3 heat conductive ceramic substrate and

A low contamination crucible for pulling monocrystals of Group III and Group V elements of the Periodic Table, comprising particularly aluminum nitride with an additive of boron nitride or a rare earth oxide. The additive concentration is up to 5% by weight, but preferably 0.5% to 3% by weight. The hardness of the crucible of the invention is 300 to 400% greater than that of undoped material subjected to the same sintering conditions.

Low-contamination AlN crucible for monocrystal pulling and method

A cable for connecting a cardiac pacemaker to an electrode inserted in the heart through the blood stream utilizes a die-clad conductor or a number ofthem, especially several die-clad strands forming a twisted conductor of the stranded type, enclosed in a covering tube of a synthetic elastomer. The core of each die-clad strand is of a highly conducting metal, such as copper or a high-copper alloy. The outer cladding is a metal selected from the group consisting of tantalum, titanium, zirconium, niobium, titanium-base alloys, platinum, platinum-iridium alloys, platinum-palladium alloys and platinum-rhodium alloys. The cladding thickness is in the range from 0.0025 to 0.035 mm, while the cord diameter is between 0.04 to 0.3 mm. When tantalum, titanium, zirconium, niobium or titanium-alloy cladding is used, the outer surface can be made electrically insulating, preferably by anodizing.

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Kleinheubach, Germany

Richard Keilberth