Gte Products Corporation

David C Ludwig

Robert J Dobbs

Joseph J Penkunas

A method for removing a paraffin wax based binder containing a fatty acid from a green article, wherein the article is made of material selected from the group consisting of ceramic powders and metallic powders, which comprises heating the article in a non-oxidizing atmosphere in a furnace by raising the temperature at a rate of about 0.5.degree. C. to 1.0.degree. C. per minute to a first temperature of about 50.degree. C. to 80.degree. C. and thereafter maintaining the first temperature for about 30 to 90 minutes to essentially completely melt the binder, raising the temperature from the first temperature at a rate of about 0.5.degree. C. to 1.0.degree. C. per minute to a second temperature of about 200.degree. C. to 225.degree. C. and thereafter maintaining the second temperature for about 30 to 90 minutes to essentially completely vaporize the paraffin wax, raising the temperature from the second temperature at a rate of about 0.5.degree. C. to 1.0.degree. C. per minute to a third temperature of about 260.degree. C. to 300.degree. C. and thereafter maintaining the third temperature for about 30 to 90 minutes to essentially completely vaporize the fatty acid, and raising the temperature from the third temperature at a rate of about 0.5.degree. C. to 1.0.degree. C. per minute to a fourth temperature of about 430.degree. C. to 480.degree. C. and thereafter maintaining the fourth temperature for about 30 to 90 minutes to insure complete vaporization of essentially all of the binder.

Method for removal of paraffin wax based binders from green articles

A composition is disclosed which is suitable for injection molding of metallic material. The composition comprises about 2.8% of about 4.5% by weight of a binder and the balance a metallic material. The binder consists essentially of about 6% to about 14% by weight of a fatty acid and the balance a hydrocarbon wax having a melting point of about 50.degree. C. to about 100.degree. C.

Composition suitable for injection molding of metal alloy, or metal

An abrasive frit is disclosed comprising particles of a silicon nitride based material. The particles have essentially sharp edges and a particle size within the range of from about 0.5 to about 150 microns. An abrasive frit is disclosed as described above except that the edges of the particles are essentially smooth. A method is disclosed for producing a abrasive frit of silicon nitride based material. The method involves forming a body of silicon nitride based material, firing the body at a sufficient temperature for a sufficient time to form a relatively low density body which is then crushed to form fragmented material a portion of which comprises essentially sharp edged particles in the above given size range, followed by separating the particles from the balance of the fragmented material. At this point the sharp edged particles can be either polished to produce essentially smooth edges particles or left as is. The particles are then sintered at sufficient temperature and pressure for a sufficient time to form sintered material having a density of at least about 96% of the theoretical density of the silicon nitride based material. The sintered material is then deaggregated, followed by separating that portion of the sintered material having a particle size in the above given size range, which is the abrasive frit, from the balance of the deaggregated material.

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Towanda, PA, United States of America

David C Ludwig