Raychem Limited

Ryan W Dupon

Mark S Thompson

Gary H Wiseman

Karin M Kinsman

Anthony C Evans

Douglas J Musolf

Amy S Chu

Linas Mazeika

Pawel Czubarow

Adam C Tanous

Martha L McCrum

Viktors Jansons

Christian Weber

Adam S Tanous

Shukri J Souri

Takeshi Tsukada

A method of forming an article having a cermet layer on a porcelain substrate, via the steps of (a) providing a substrate made a porcelain comprising one or more crystalline oxide phases dispersed in a glassy matrix, the glassy matrix containing 0.25 to 45.0 weight % of a reducible metal oxide having a reduction potential of between -1.0 and +3.5 E.degree./V; and (b) heating the substrate in a reducing atmosphere to form on at least one surface of the substrate a layer of cermet comprising elemental metal which is a reduction product of the reducible metal oxide. The article may be used as a substrate for magnetic recording disks.

Magnetic disk comprising a substrate with a cermet layer on a porcelain

An electrode is formed on a substrate such as a varistor, a PTC ceramic, or a piezoelectric ceramic by coating a surface of the substrate with a combination of a metal source and a source of reducing carbon. The substrate and/or the combination is an absorber of microwave radiation. Irradiation with microwave radiation causes a carbothermic reduction to occur, converting the metal source to a metal electrode on the substrate.

Method of forming an electrode on a substrate

A method of making varistor chips is disclosed. A workpiece of varistor material is sliced into slices of varistor material. The slices are in turn diced to make the varistor chips. The chips are etched in an etchant such as dilute citric acid to remove from their surfaces varistor material damaged during the slicing and/or dicing operations. Otherwise, the damaged varistor material adversely affects the leakage current characteristics of the varistor chips.

Method of making varistor chip with etching to remove damaged surfaces

A method for making a high strength porcelain for use as an insulator or a structural ceramic, comprising: A) forming a mixture comprising alumina, clay and a fluxing material; B) forming the mixture into a shaped article; and C) firing the shaped article.

High strength porcelain and method therefor

A porcelain having 9 to 55% by weight of SiO.sub.2, 36 to 87% by weight of Al.sub.2 O.sub.3, 0 to 2.0% by weight of Fe.sub.2 O.sub.3, 0 to 1.0% by weight of TiO.sub.2, 0 to 0.5% by weight of CaO, 0 to 0.5% by weight of MgO, 1.0 to 4.0% by weight of K.sub.2 O and Na.sub.2 O combined, and 0.25 to 25.0% by weight of bismuth oxide is disclosed. The porcelain has unexpectedly high unglazed bending strength and may be used for dielectric and structural applications.

A metal oxide dielectric dense body, comprising (I) grains having a predominant crystalline phase (a) a primary metal oxide selected from the group consisting of silicon and magnesium oxide and (b) optionally a secondary metal oxide selected from the group consisting of aluminum and zinc oxide and (II) between about 1 and about 20 atom % bismuth, vanadium, or boron oxide or combination thereof, discontinuously located at the boundaries of the crystalline grains or as inclusions in the crystalline grains, the atom %'s based on the total atoms of bismuth, vanadium, boron, silicon, magnesium, aluminum, and zinc. The dense body has a density which is at least 95% of theoretical.

Metal oxide dielectric dense bodies, precursor powders therefor, and

A metal oxide dielectric dense body, comprising (I) grains having a predominant crystalline phase (a) a primary metal oxide selected from the group consisting of silicon and magnesium oxide and (b) optionally a secondary metal oxide selected from the group consisting of aluminum and zinc oxide and (II) between about 1 and about 20 atom % bismuth, vanadium, or boron oxide or combinations thereof, discontinuously located at the boundaries of the crystalline grains or as inclusions in the crystalline grains, the atom %'s based on the total atoms of bismuth, vanadium, boron, silicon, magnesium, aluminum, and zinc. The dense body has a density which is at least 95% of theoretical.

Growing community of inventors

San Carlos, CA, United States of America

Ryan W Dupon