To provide a diamond sintered compact (polycrystalline diamond) which is excellent in oxidation resistance, small in chemical wear, and high in mechanical strength and hardly undergoes cleavage and mechanical wear even upon receiving a large-load stress, to provide a method for producing the same, and to provide uses of the same.
There are provided a diamond sintered compact composed of a diamond region prepared by sintering diamond grains having an average grain diameter of 0.08-150 μm and having a larger nitrogen content than a boron content and a nondiamond region, wherein the diamond region accounts for 80-98 vol.%, the surfaces of the diamond grains contain ≥15 to ≤1,000 ppm boron, the region with a boron content of 3 ppm or less accounts for 60-95 vol.% of the diamond region and occupies 10% or more of the length of bond between diamond grains and voids may be present in a specified proportion; a method for producing the same; and a tool, die, or discharge electrode material using the diamond sintered compact.
SHIMAZAWA KEIKO
YOSHIDA MINORU
Naomi Kamino