Abstract: An improved nozzle for use with abrasive and/or corrosive materials is formed of sintered ceramic compositions having high temperature oxidation resistance, high hardness and high abrasion and corrosion resistance. The ceramic may be a binary solid solution of a ceramic oxide and silicon nitride, and preferably a ternary solid solution of a ceramic oxide, silicon nitride and aluminum nitride. The ceramic oxide is selected from a group consisting of Al.sub.2 O.sub.3, Y.sub.2 O.sub.3 and Cr.sub.2 O.sub.3, or mixtures thereof. Titanium carbide particles are dispersed in the ceramic mixture before sintering. The nozzles are encased for protection from external forces while in use by a metal or plastic casing.

Abstract: Cermet compositions having high temperature oxidation resistance, high hardness and high abrasion and wear resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies, comprising a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Also disclosed are novel ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride.The cermet compositions are designed particularly to provide high temperature resistant refractory coatings on metal substrates, preferably molybdenum or tungsten substrates.

Abstract: Cermet compositions having high temperature oxidation resistance, high hardness and high abrasion and wear resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies, comprising a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Also disclosed are novel ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride.The cermet compositions are designed particularly to provide high temperature resistant refractory coatings on metal substrates, preferably molybdenum or tungsten substrates.

Abstract: A thermionic converter unit for use in a nuclear reactor to generate current, which can be constructed at low cost and which efficiently utilizes the nuclear fuel. The reactor utilizes an array of thermionic emitters whose peripheries are fluted so that a bulge of one emitter interfits the depression of another, to permit compact mounting, each emitter having several fuel passages located in the bulged portions for holding nuclear fuel and having a central collector passage for holding a thermionic collector. The emitters are constructed of rods of tungsten containing a small amount of thorium oxide, the thorium oxide not only improving the machinability of the tungsten but making it an efficient emitter.

Abstract: Cermet composition having high temperature oxidation resistance, high abrasion and corrosion resistances, and good thermal shock resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies, comprising a sintered body of particles of stainless steel or molybdenum, in a ceramic phase comprised of a ceramic oxide, particularly a ceramic mixture of chromium oxide and aluminum oxide, and forming a coating of chromium oxide as an oxidation barrier around the metal particles, to provide oxidation resistance for the metal particles.The cermet compositions are designed particularly to provide high temperature resistant refractory coatings on stainless steel or molybdenum substrates.