The Carborundum Company

Stemcor Corporation

Thomas A Myles

Jonathan J Kim

Curtis E Zimmer

Alan R Lebold

Bruce J Dover

A method of producing near net shape fusion cast refractories. The method includes the steps of continuously introducing refractory particles into a melting furnace, rapidly heating the particles, depositing the heated particles into a melt pool, continuously introducing the molten material into a mold, and continuously withdrawing a solidified body from the mold as the molten material continually solidifies. The above stated method produces a fusion cast refractory having a generally random, fine, uniform microstructure; uniform chemistry; and generally evenly distributed closed pores.

Method of producing near net shape fused cast refractories

Fused cast refractory moldings having a random microstructure, which are near in size and configuration to the desired final shape, and process and apparatus used in their manufacture are described. The process includes rapid melting of the refractory material followed by controlled rapid cooling. Laminated composite fused cast refractories may be produced.

Near net shape fused cast refractories and process for their manufacture

A refractory moldable composition which, upon drying, sets up to refractory shapes which are strongly adherent to the molding surfaces and are essentially crack-free, contains about 45 to about 65% of a liquid vehicle, such as water; about 21 to about 26% ceramic fiber; about 7 to about 30% finely divided silica; and sufficient adhesion enhancing agent to impart from about 18 to about 50 grams per square centimeter adherence to steel. The molded composition adheres excellently to molding surfaces and dries to give an essentially crack-free refractory shape, useful as thermal insulation at temperatures up to 1300.degree. C. The composition may optionally include hollow plastic or ceramic spheres.

Refractory moldable composition

A shrink resistant flexible ceramic fiber and its process of manufacture which comprises melting from about 40 to 65 weight percent of alumina with from about 35 to about 60 weight percent of silica, forming fibers from the melt, rapidly solidifying the fibers, heating the fibers to a sufficient temperature for a sufficient time to form microcrystals and cooling the fibers to below the crystallization temperature before macrocrystals can form.

Shrink-resistant refractory fiber and process for making same

Refractory moldable composition containing ceramic fiber and colloidal

A ceramic fiber module, suitable for lining furnaces, comprises a weldable (metallic or perforate refractory) backing and a number of ceramic fiber mats cemented to the backing by the edge of the mat, so as to leave a portion of the backing accessible between mats or on their perimeter, for welding. The weldable backing is welded to a metallic substrate, preferably by use of spherical attachments, to provide thermal protection to the metallic substrate.

Ceramic fiber module attachment system

A method for the preparation of pyrophosphates such as SiP.sub.2 O.sub.7 is disclosed, whereby the undesired formation of by-products such as Si.sub.2 P.sub.2 O.sub.9 is minimized. Such pyrophosphates are particularly suitable for the formation of solid semi-conductor diffusion sources, wherein the presence of by-product is seriously detrimental.

Preparation of pyrophosphates

Solid diffusion sources for phosphorus doping comprise from 10 to 95 percent SiP.sub.2 O.sub.7 with an inert phase of ZrP.sub.2 O.sub.7. Such materials may be hot-pressed to obtain diffusion source wafers of the appropriate dimensions and porosity. A preferred composition comprises from 25 to 75 weight percent SiP.sub.2 O.sub.7, the balance ZrP.sub.2 O.sub.7. Fabrication parameters range from about 750 psi to about 6,000 psi pressure during hot-pressing, at temperatures from about 800.degree.C to about 1450.degree.C.

Hot-pressed solid diffusion sources for phosphorus

Solid diffusion sources for phosphorus doping comprise from 5 to 95 percent SiP.sub.2 O.sub.7 with an inert phase of ZrP.sub.2 O.sub.7. While such materials may be hot-pressed, it is preferred to cold-press and sinter to obtain diffusion source wafers of the appropriate dimensions and porosity. A preferred composition comprises from 25 to 75 weight percent SiP.sub.2 O.sub.7 the balance ZrP.sub.2 O.sub.7. Fabrication parameters range from about 4000 psi to about 20,000 psi pressure during cold-pressing, and from about 1080.degree.C to about 1190.degree.C firing temperature.

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Jamestown, NY, United States of America

Thomas A Myles