PURPOSE: To increase wear resistance by executing heat treatment in a nitrogen gas current after mixing 2.5 - 10wt% cubic boron nitride power in ≤0.5μm grain diameter and 15 - 30wt% org. high molecular material with a diamond powder in ≤0.5μm grain diameter and sintering at the temp. of ≥1,350°C in the state of filling this powder in an alloy container.

CONSTITUTION: After mixing 2.5 - 10wt.% cubic boron nitride powder in ≤0.5μm grain diameter and 15 - 30wt.% org. high molecular material with a diamond powder 5 in ≤0.5μm grain diameter, heat treatment is executed in a nitrogen gas current. Then this powder is sintered at the temp. of ≥1,350°C under diamond state zone in the state of filling in an alloy container or laminating with an allow base body and a desired fine grain diamond sintering body is obtd.