MINIATURE DRILL MADE OF MICRO POWDER ORGANIZATION PRESSURIZED/SINTERED BODY GIVING GOOD BREAKAGE RESISTANCE AND ABRASION RESISTANCE IN RAPID DRILLING

摘要

PROBLEM TO BE SOLVED: To provide a miniature drill made of micro powder organization pressurized/sintered body for giving good breakage resistance and abrasion resistance in rapid drilling. SOLUTION: In the miniature drill with 0.1-1.6 mm of outer diameter, a dispersion phase of a micro powder organization occupies 80-95 area % in average, and the remaining is made of the pressurized/sintered body having the micro powder organization consisting of a bonding phase and unavoidable impurity. The dispersion phase constituting the pressurized/sintered body is formed with a C monophase of which rate of Co and Cr substantially contained in WC in solid solution is Co: 0.1-3 mass % and Cr: 0.1-2 mass % in average value occupied in the dispersion phase, and the bonding phase is formed with a Co base alloy monophase containing 1-8 mass % Cr in average in the bonding phase. The pressurized/sintered body contains 0.1-1 mass % V of the entire pressurized/sintered body, and the V aggregates in a boundary part between the dispersion phase and the bonding phase.