Ford Motor Company Limited

Gerald J Tennenhouse

Gary Mark Crosbie

Halina S Wroblowa

Ragnar P Tischer

John A Mangels

Ronald S Gordon

Ralph W Sutton

Franklin D Runkle

Method and apparatus for increasing wear life of ceramic tools

This invention relates to electrically conductive ceramic materials suitable for use at high temperatures and in the presence of corrosive environments, e.g., the sodium-sulfur battery. The ceramic material comprises chromium oxide (Cr.sub.2 O.sub.3) doped with at least 0.02 mole percent lithia, wherein the chromium oxide contains less than about 0.5 mole percent of any impurity selected from the group consisting of sodium oxide and potassium oxide, based on moles of chromium oxide. The doped chromium oxide can be used as coatings on metal or metal alloy so as to form corrosion resistant current collectors which may be container/current collectors.

Electronically conductive lithia doped oxide ceramics for use in sodium

This invention relates to electrically conductive current collectors suitable for use at high temperatures and in the presence of corrosive environments, e.g., the sodium-sulfur battery. The current collectors comprises metal or metal alloys coated with ceramic material comprising chromium oxides doped with at least 0.05 mole percent magnesia. The corrosion resistant current collectors may be container/current collectors.

Electronically conductive magnesia doped oxide ceramics for use in

A method of densifying a reaction bonded silicon nitride article is disclosed. In accordance with the broadest principles disclosed, a densification aid is incorporated into a reaction bonded silicon nitride article. The so-made reaction bonded silicon nitride article is enclosed in a chamber which also contains a mixture of silicon nitride powder and powder the same as the densification aid incorporated into the reaction bonded silicon nitride article. The reaction bonded silicon nitride article, and the powder mixture associated therewith, is subjected to a nitrogen gas pressure sufficient to prohibit a significant volatilization of silicon nitride at a sintering temperature. The reaction bonded silicon nitride article, the powder mixture and nitrogen gas associated therewith are heated to a temperature above 1700.degree. C. for a time sufficient to permit sintering of that article whereby the strength of the reaction bonded silicon nitride article is increased. In accordance with preferred teachings, the densification aid can be selected from the group of materials consisting of magnesium oxide, yttrium oxide, cerium oxide and zirconium oxide.

Method of densifying a reaction bonded silicon nitride article

A method for preparing shaped, green ceramic compacts suitable for firing to form high density .beta.'-alumina containing ceramic bodies comprising: (1) mixing between about 2.5 parts by weight and about 4.5 parts by weight of a ceramic composition comprising at least about 80 weight percent of aluminum oxide and from about 5 to about 15 weight percent of sodium oxide with 1 part by weight of a binder composition consisting essentially of between about 20 weight percent and about 35 weight percent of polyvinyl pyrrolidone having a number average molecular weight (M.sub.n) between about 20,000 and about 160,000 and between about 80 weight percent and about 65 weight percent of ethylene glycol; (2) extruding the mixture so formed through a die of desired configuration; and (3) heating the extrudate at temperatures and for periods of time necessary to evaporate the ethylene glycol solvent and burn off the polyvinyl pyrrolidone.

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Southfield, MI, United States of America

Gerald J Tennenhouse