HIGH SPEED MACHINING OF TITANIUM ALLOYS USING CERAMIC CUTTING TOOLS

TITANIUM MACHINING HAS INCREASED SUBSTANTIALLY DURING THE PAST 25 YEARS BUT DESPITE INTENSE INTEREST IN FINDING IMPROVED TOOL MATERIALS,WC-6 WT. % CO IS STILL USED AT CUTTING SPEEDS LESS THAN 75 M/MIN. RECENT WORK AT CERAMATEC SHOWED THAT NOVEL CERAMIC CUTTING TOOLS COULD BE USED TO MACHINE TITANIUM ALLOYS WITH 30-75% LESS FLANK WEAR THAN CONVENTIONAL CEMENTED CARBIDES AT SPEEDS OF 100-175 M/MIN. DESPITE THIS SUCCESS, FURTHER IMPROVEMENT IS NECESSARY IN ORDER TO INCREASE THE LIFE OF CERAMIC CUTTING TOOLS BEFORE COMMERCIALIZATION WILL OCCUR. THE PROPOSED PHASE I RESEARCH ADDRESSES CRITICAL ISSUES WHICH WILL DEMONSTRATE THE FEASIBILITY OF INCREASING THE APPARENT FRACTURE TOUGHNESS AND DEFORMATION RESISTANCE OF CERAMIC CUTTING TOOLS WHICH HAVE ALREADY SHOWN PROMISE FOR TITANIUM MACHINING. THE RESULTING CERAMIC WILL HAVE HIGH THERMAL CONDUCTIVITY, HIGH FRACTURE TOUGHNESS, GOOD CREEP RESISTANCE AND MODERATE CHEMICAL STABILITY. THE PHASE I RESEARCH WILL ANSWER CRITICAL QUESTIONS NECESSARY FOR THE SUCCESSFUL DEVELOPMENT OF CERAMIC CUTTING TOOLS DURING PHASE II.