417 ダイヤモンド含有超硬合金の低温焼結技術(摩擦・摩耗材料)

概要

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Rock bits are used in a variety of ground-drilling applications for the exploration of natural resources, such as petroleum, natural gas, water and geothermal energy. Cemented carbide with diamond powders are fabricated to extend bit life. The pulsed electric current sintering (PECS) was used to avoid graphitization of diamond powders by fast heating and short holding time for sintering. Additionally, phosphorus was added to raw powders to decrees a sintering temperature. The additive allows to decrease sintering temperature about 200K from 1200℃. Sintering period of 10min was enough to obtain dense matrix materials. Wear of fabricated rock bits was evaluated by grinding of a rock under 20MPa of pressure, and 0.2m/s of a turning velocity for 60min. Although, wear of a rock bit without diamonds was 36mm^3/h, and that of fabricated rock bits was negligibly small in those experimental conditions.
2007-11-16