Manufacture of hard sintered alloys

Claim 1

A MIX FOR MAKE REFRACTORY CONCRETE CONSISTING OF FROM 5 TO 60% OF CALCIUM-ALUMINATE CEMENT AND FROM 40 TO 95% CALCINED CLAY CONTAINING FROM 50 TO 99% ALUMINA, ONE OF SAID COMPONENTS CONTAINING FROM 1 TO 25% HYDROGEN FLUORIDE. LOYS, WHICH COMPRISES REDUCING AND CARBURIZING A FINELY POWDERED MIXTURE OF REDUCIBLE COMPOUNDS OF ZIRCONIUM AND TUNGSTEN IN THE STOICHIOMETRIC PROPORTIONS OF 3ZR TO 1W, WITH CARBON SUFFICIENT FOR REDUCTION OF SAID COMPOUNDS TO THE METALLIC STATE AND FOR CARBURIZATION OF THE LIBERATED METALS, AT A TEMPERATURE BETWEEN ABOUT 2000*C. AND ABOUT 2300*C. WHILE PUMPING OFF SIMULTANEOUSLY LIBERATED REACTION GASES, WHEREBY TO FORM A SOLID SOLUTION HAVING THE COMPOSITION 3ZRC.WC, COOLING THE SOLID SOLUTION AT A CONTROLLED SLOW RATE THROUGH THE TEMPERATURE RANGE FROM 1600*C. DOWN TO 1000*C. SO AS TO REARRANGE THE METALLIC ATOMS IN THE COMMON CRYSTALLINE LATTICE ACCORDING TO A SUPERLATTICE, WHEREBY TO CONVERT THE SOLID SOLUTION INTO A CUBIC DOUBLE CARBIDE COMPOUND CORRESPONDING TO THE FORMULA ZR3WC4, FORMING A HOMOGENEOUS FINELY POWDERED MIXTURE OF AN APPRECIABLE AMOUNT OF SAID DOUBLE CARBIDE,, AT LEAST ONE METAL OF THE IRON GROUP, AND AT LEAST ONE REFRACTORY METAL CARBIDE SELECTED FROM THE GROUP CONSISTING OF TUNGSTEN CARBIDE, TITANIUM CCARBIDE, VANADIUM CARBIDE, TANTALUM CARBIDE, MOLYBDENUM CARBIDE, CHROMIUM CARBIDE AND COLUMBIUM CARBIDE, COMPRESSING THE MIXTURE AND SINTERING AT A TEMPERATURE BETWEEN ABOUT 1200*C. AND ABOUT 1600*C.