GRAIN GROWTH CONTROL IN THE NET-SHAPE PROCESSING OF NANOSTRUCTURED WC-CO COMPOSITES

NANOSTRUCTURED WC-CO MATERIALS HAVE THE POTENTIAL FOR REVOLUTIONIZING THE HARDFACING, CUTTING TOOL AND DRILL BIT INDUSTRIES. DRAMATIC IMPROVEMENTS IN MECHANICAL PROPERTIES AND PERFORMANCE HAVE ALREADY BEEN DEMONSTRATED. FURTHER RESEARCH ON DECREASING WC GRAIN SIZE OF THE CONSOLIDATED MATERIAL IS NOW SEEN TO BE OF THE HIGHEST PRIORITY, SINCE ITIS KNOWN THAT WC-CO PROPERTIES IMPROVE SYSTEMATICALLY WITH DECREASING NANOSTRUCTURAL SCALE. STATE-OF-THE-ART WC-CO NANOSTRUCTURES ARE AT THE 50-100 NM LEVEL. WE BELIEVE THAT THE USE OF GRAIN GROWTH INHIBITORS WILL PERMIT AN ORDER OF MAGNITUDE REDUCTION WC GRAIN SIZE, WITH CORRESPONDING IMPROVEMENTS IN MECHANICAL PROPERTIES. THE COST OF NANOSTRUCTURED WC-CO PARTS MANUFACTURE CAN ALSO BE REDUCED INJECTION MOLDING. BY PERFECTING A NET-SHAPE FORMING CAPABILITY, SUCH AS POWDERWE PROPOSE (1) TO INTRODUCE VC (A KNOWN GRAIN GROWTH INHIBITOR) INTO NANOSTRUCTURED WC-CO POWDER BY SPRAY CONVERSION PROCESSING, (2) TO DEMONSTRATE LIQUID PHASE SINTERING OF AN EXTRUDED WC, VC-CO ROD, (3) TO REALIZE DECREASED WC GRAIN SIZE IN THE SINTERED ROD, AND (4) TO DETERMINE THE DEGREE OF HARDNESS IMPROVEMENT THAT CAN BE ATTRIBUTED TO THE REDUCED WC GRAIN SIZE. THE RESEARCH WILL LAY THE GROUNDWORK FOR THE FUTURE DEVELOPMENT OF NET-SHAPE PIM PROCESSING OF NANOSTRUCTURED WC-CO PARTS, WHICH EXHIBIT SUPERIOR PROPERTIES AND PERFORMANCE.