Gte Products Corporation

Joseph J Penkunas

Theodore E Smith, Jr

Jack L Burwick

David C Ludwig

A method for producing metal carbide grade powders which comprises forming a wax mixture consisting essentially of in percent by weight about 5 to about 15 paraffin oil, with the balance being an esterified wax and paraffin, heating the wax mixture to a temperature above the melting point to melt the wax mixture and maintain it in the molten state, forming a powder-wax mixture consisting essentially of metal carbide powder, a binder metal, and the wax mixture while heating to a temperature above the melting point of the wax mixture to maintain the wax mixture in the molten state to result in a uniform distribution of the wax mixture on the carbide and binder metal particles, forming a slurry of the powder-wax mixture and water, attritor milling the slurry at a temperature below the melting point of the wax mixture, and removing water and agglomerating to produce metal carbide grade powder wherein a densified article made therefrom exhibits less linear shrinkage than articles made from carbide grade powder absent the esterified wax. The shrinkage decreases as the content of esterified wax in the wax mixture increases.

Method of producing metal carbide grade powders and controlling the

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 method for producing metal carbide grade powders suitable for isostatic compaction which comprises combining a binder metal powder with an esterified wax and heating the wax to a temperature above the melting point of the wax to melt the wax and maintain it in the molten state to form a first mixture, with the amount of wax being sufficient to result in a level of wax in the subsequently produced second mixture of no greater than about 1/2% by weight, combining a metal carbide powder component with the first mixture while maintaining the wax in the molten state, forming a slurry of the second mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing water from the resulting attritor milled mixture to form the metal carbide grade powder.

Method for producing tungsten carbide grade powders suitable for

A method is disclosed for producing metal carbide grade powders, which comprises forming a wax mixture consisting essentially of in percent by weight about 10 to 60 of an organic compound additive which is a solid at room temperature and contains a C.dbd.O group, about 5 to about 50 oils, and the balance paraffin, heating the wax mixture to a temperature above the melting point of the wax mixture and maintaining the temperature, forming a powder-wax mixture of metal carbide powder, a binder metal selected from the group consisting of cobalt, nickel, and combinations thereof, and the wax mixture, while heating the carbide powder, binder metal and wax mixture to a temperature above the melting point of the wax mixture and maintaining the temperature, to result in a uniform distribution of the wax mixture on the carbide and binder metal particles, forming a slurry of the powder-wax mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing the water from the resulting attritor milled powder-wax mixture and agglomerating the mixture to produce the metal carbide grade powder wherein a densified article made therefrom exhibits essentially no pores that are greater than about 10 micrometers in diameter after sintering at about 1350.degree. C. to 1540.degree. C.

Method for producing metal carbide grade powders

A method is disclosed for producing metal carbide grade powders, which comprises dry milling metal carbide powder which can be tungsten carbide, titanium carbide, tantalum carbide, niobium carbide, vanadium carbide, chromium carbide, and combinations thereof to increase the surface area of the powder particles to result in essetially all of the powders being converted to single crystals, forming a mixture of the resulting dry milled carbide powder, a binder metal which can be cobalt, nickel, and combinations thereof, and a wax, while heating the carbide powder, the binder metal and the wax to a temperature above the melting point of the wax and maintaining the temperature to result in a uniform distribution of the wax on the carbide and binder metal particles, forming a slurry of the mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing the water from the resulting attritor milled mixture and aggiomerating the mixture to produce the metal carbide grade powder wherein a densified article made therefrom exhibits essentially no pores that are greater than about 10 micrometers in diameter after sintering at from about 1350.degree. C. to about 1540.degree. C.

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Sayre, PA, United States of America

Joseph J Penkunas