Cemented titanium carbide tool for intermittent cutting application

Abstract

A hard sintered carbide composition and the method of making such composition for use as a cutting material or for use as wear parts or dies and the like, is disclosed. The composition consists essentially of a titanium carbide phase bound together by a binding alloy principally composed of molybdenum and nickel; the titanium carbide contains controlled amounts of dissolved vanadium carbide and/or titanium nitride. The binding alloy is characterized by the addition of aluminum in controlled amounts and chromium may be added to the binding alloy as a partial substitute for some of the aluminum. The presence of the dissolved vanadium carbide and/or titanium nitride produces a grain refinement in the carbide phase and the presence of the aluminum tends to form a nickel aluminide in the binding alloy which is of a finely divided character. The presence of two or more of the elements; vanadium carbide, titanium nitride and aluminum produce an unprecedented improvement in the deformation resistance of a TiC--Ni--Mo composition. The method requires that the binding alloy powder and the carbide powders be selected as to size (about 3-4 microns) be milled with the additive powders and the compacted charge then be sintered at about 1400.degree. C in closed graphite trays in a furnace evacuated to less than 1 micron of mercury pressure.