Sintering process for forming a die

Claim 1

IN A METHOD FOR PRODUCING A SHAPING DIE COMPOSED OF A COMPOSITE BODY CONTAINING TITANIUM-BASE CARBIDE, SUBSTANTIALLY THE BALANCE BEING A MATRIX-FORMING INFILTRANT METAL; THE STEPS COMPRISING MIXING POWDERED TITANIUM-BASE CARBIDE PARTICLES WITH UP TO ABOUT 10% BY WEIGHT OF AN AUXILIARY BINDER METAL SELECTED FROM THE GROUP CONSISTING OF NICKEL, COBALT AND IRON; FORMING A POROUS, COHERENT, SKELTON BODY THEREFROM COMPRISING ABOUT 40% TO 80% BY VOLUME OF SAID TITANIUM-BASE CARBIDE HAVING INTERCOMMUNICATING PORES THERETHROUGH; ROUGH MACHINING SAID SKELETON BODY INTO SUBSTANTIALLY THE SHAPE OF A DIE WITH PASSAGEWAYS CORRESPONDING TO INLET AND OUTLET PORTS SEPARATED BY A THIN POROUS BARRIER DEFINING A RESERVOIR; PLACING IN SAID RESERVOIR SAID MATRIX FORMING INFILTRANT METAL SELECTED FROM THE GROUP CONSISTING OF IRON, COBALT AND NICKEL, MIXTURES OF THESE METALS WITH EACH OTHER, AND WITH AT LEAST ONE OF THE METALS CHROMIUM, MOLYBDENUM, TUNGSTEN, VANADIUM, COLUMBIUM AND TANTALUM; SUBJECTING SAID ROUGH MACHINED SKELETON DIE BODY AND SAID INFILTRANT METAL CONTAINED THEREIN TO AN INFILTRATION TREATMENT COMPRISING HEATING THE WHOLE TO A TEMPERATURE RANGING FROM ABOUT 25* C. TO 250* C. ABOVE THE LIQUIDS TEMPERATURE OF THE INFILTRANT METAL AT A SUBATMOSPHERIC PRESSURE BELOW ABOUT 1000 MICRONS OF MERCURY FOR A TIME SUFFICIENT TO ENABLE THE POROUS SKELETON DIE BODY TO BE COMPLETELY INFILTRATED; THEN FURTHER SUBJECTING SAID INFILTRATED DIE BODY TO A MATRIX STABILIZING TREATMENT IN SITU WITHIN SAID INFILTRATION TEMPERATURE RANGE FOR A TIME SUFFICIENT TO MODIFY THE MICROSTRUCTURE OF SAID SKELETON DIE BODY, THE TOTAL TIME FOR BOTH THE INFILTRATION AND STABILIZING TREATMENTS RANGING FROM ABOUT 1/2 TO 2 1/2 HOURS PER CUBIC INCH OF SKELETON BODY; COOLING SAID TREATED BODY TO ROOM TEMPERATURE WHEREBY A COMPOSITE DIE BODY IS PRODUCED HAVING A MICROSTRUCTURE COMPRISING A CONTINUOUS MATRIX OF SUBSTANTIALLY SAID MATRIX-FORMING INFILTRANT METAL HAVING DISPERSED THERETHROUGH FINE PARTICLES OF A PRECIPITATE AND ESSENTIALLY ISOLATED LARGER TITANIUM-BASE CARBIDE PARTICLES AND PARTICLE AGGREGATES HAVING SUBSTANTIALLY SPHEROIDAL POLYGONAL SHARPES; AND THEN FINISH-MACHINING SAID DIE BODY TO DESIRED DIMENSIONS.