US2091903A - Method of treating tungsten carbide - Google Patents

Description

Aug. 3l, 1937. H. T. BAGGETT ET AL METHOD 0F TREATING TUNGSTEN CARBIDE Filed Nov. 4, 1935 Henry .7? 34151962? Gorkam Z0. Zdoods INVENTOR ATTORNEY Patented Aug. '31, 193

Henry T. Baggett and ton, Tex., assignors Gorham W. Woods; Housto Hughes Tool Company,

Houston, Tex, a corporation of Texas Application November 4, 1935, Serial No. 48,193

4 Claims.

Our invention relates to a method or process of making hard materials, such as tungsten carbide, employed as diamond substitutes in facing tools and the like.

In the usual method of treating tungsten carbide, the materials are fused in a crucible at high temperatures and are discharged from the crucible directly into a cold mold or quenching medium. The resulting alloy is hard and crystalline, but is to some extent porous because of occluded air pockets therein.

It is an object of our invention to subject the molten tungsten carbide to compression in its molten state so as to eliminate the air and gas. occluded therein and to prevent the porous consistency of the carbide otherwise existing.

We also desire to obtain a more rapid and thorough quenching of the alloy due to its thinner cross section where it is introduced into the oil.

In the drawing herewith is a diagrammatic view, partly in section, illustrating the application of the invention.

The proper quantities and proportions of tungsten, carbon, etc. are fused in a crucible illustrated at I. This may preferably be done by electrical means, the crucible being largely of graphite. I

When the charge is properly melted, it is poured, as shown in the drawing, into a quenching medium 2 which is preferably oil. On the pouring of the molten tungsten carbide from the crucible to the quenching medium, it is passed between two compression rolls 3 which are rotated to move the molten metal downwardly and to exert a heavy pressure thereon to eliminate all air orgas therein and to deliver the metal to the quenching tank in thin sheets which may be cooled instantly by the quenching medium.

we find that tungsten carbide thus treated is harder and of better quality than where not so compressed and quenched. The porous condition of the alloy usually resulting from oldmethods is avoided. Further, the carbide in the form of thin sheets is more easily broken up and pulverized for use than is the case where it is poured into a cold mold or where it is poured directly into a quenching bath. r

What we claim as new is:

1. A process of forming tungsten carbide comprising bringing the ingredients thereof to a molten condition in a crucible, positioning said crucible at a point spaced above compression rolls, pouring said tungsten carbide in its molten condition in drops downwardly between the. heavy compression rolls to eliminate occluded gases, and forming the same into thin sheets and then quenching said sheets in a liquid bath.

2. A process of forming tungsten carbide comprising fusingthe charge, partly cooling the tungsten carbide in the air while pouring said charge in a molten condition between compression rolls to form the material into thin sheets and then abruptly cooling the same in a liquid quenching medium.

3. A process of forming tungsten carbide including fusing a charge of material to a molten condition, cooling the same to a semi-plastic condition, compressing the charge to eliminate occluded gases, and simultaneously forming the metal into thin sheets and then abruptly cooling said sheets.

4. A process of cluding fusing -a condition, dropping the charge slowly through the air to partly cool the same, compressing the charge to eliminate occluded gases, and thenabruptly cooling the compressed carbide.

forming tungsten carbide in- HENRY T. BAGGE'IT. GORHAM W. WOODS.

charge of material to a molten

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