Cubic boron nitride polycrystal, cutting tool, wear-resistant tool, grinding tool, and method of producing cubic boron nitride polycrystal

• Main Authors: ISHIDA YUH, YAMAMOTO KATSUKO, SUMIYA HITOSHI
• Format: Patent
• Language: English
• Published: 04.11.2015
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; ALLOYS; APPARATUS THEREFOR; ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; CRYSTAL GROWTH; FERROUS OR NON-FERROUS ALLOYS; GRINDING; LIME, MAGNESIA; METALLURGY; PERFORMING OPERATIONS; POLISHING; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; REFRACTORIES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; SLAG; TOOLS FOR GRINDING, BUFFING, OR SHARPENING; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; TREATMENT OF NATURAL STONE; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

A cubic boron nitride polycrystal includes cubic boron nitride, the cubic boron nitride having an average grain size of not more than 150 nm, a ratio b/a being not more than 0.085 in measurement of Knoop hardness at 23 DEG C plus or minus 5 DEG C under a test load of 4.9 N, the ratio b/a being a ratio between a length a of a longer diagonal line and a length b of a shorter diagonal line of a Knoop indentation. The invention also relates to a cutting tool, a wear-resistant tool, a grinding tool, and a method of producing the cubic boron nitride polycrystal. The cubic boron nitride polycrystal is ductile.