Abstract: A drilling tip includes a tip main body that has a posterior end portion having a columnar or disk shape centered on a tip center line and a distal end portion and is made of a cemented carbide and a hard layer that coats the distal end portion and is made of a polycrystalline diamond sintered body. The distal end portion has a convex portion, and a concave portion. A diameter D of the posterior end portion is 8 mm to 20 mm. A ratio r1/D of a radius r1 of the convex portion is 0.1 to 0.65, and a ratio r2/D of a radius r2 of the concave portion is 0.05 to 3.0. An angle formed by a straight line that connects a tangent point which the convex portion tangents to the concave portion and a center of the convex portion to each other is 20° to 90°.

Abstract: A drilling tip includes a tip main body that has a posterior end portion having a columnar or disk shape centered on a tip center line and a distal end portion and is made of a cemented carbide and a hard layer that coats the distal end portion and is made of a polycrystalline diamond sintered body. The distal end portion has a convex portion, and a concave portion. A diameter D of the posterior end portion is 8 mm to 20 mm. A ratio r1/D of a radius r1 of the convex portion is 0.1 to 0.65, and a ratio r2/D of a radius r2 of the concave portion is 0.05 to 3.0. An angle formed by a straight line that connects a tangent point which the convex portion tangents to the concave portion and a center of the convex portion to each other is 20° to 90°.

Abstract: A polycrystalline diamond sintered material tool includes: a cemented carbide substrate, which is mainly composed of WC and includes Co; and a diamond layer containing a metal catalyst made of Co provided on the cemented carbide substrate. The average layer thickness of a Co rich layer formed in an interface between the cemented carbide substrate and the diamond layer is 30 ?m or less. CMAX/CDIA is 2 or less when CDIA is an average content of Co included in the diamond layer and CMAX is a peak value of a Co content in the Co rich layer. D/DO is less than 2 when D is an average grain size of WC particles in a region from the interface between the cemented carbide substrate and the diamond layer to 50 ?m toward an inside of the cemented carbide substrate; and DO is an average grain size of WC particles.

Abstract: A drilling tip according to the disclosure has a tip body which is provided with a tip portion tapered toward a tip side of the tip body; and a hard layer which is formed on a surface of the tip portion of the tip body, an outermost layer of the hard layer is a cBN sintered material having 70 to 95 vol % of cBN grains, and when a cross-sectional structure of the outermost layer is observed, a binder phase having a width of 1 nm or greater and 30 nm or less and containing Al, B, and N, and in which a ratio of an O content to an Al content is 0.1 or less exists between neighboring cBN grains.

Abstract: A drill bit insert attached to a tip portion of a drill bit to perform drilling, includes: an insert body (1) that includes: a rear end portion buried in a bit body of the drill bit; and a tip portion protruding from a surface of the drill bit and tapered toward a tip side of the insert body, in which a surface of at least the tip portion of the insert body (1) made of polycrystalline cubic boron nitride compact (4) sintered using a catalytic metal containing Al and at least one selected from the group consisting of Co, Ni, Mn, and Fe and containing 70 vol % to 95 vol % of cubic boron nitride.

Abstract: In a drill bit insert of the present invention, an insert body of the drill bit insert includes: a rear end portion forming a columnar shape or a disk-like shape; an intermediate portion having an outer diameter smaller than that of the rear end portion; and an end portion having an outer diameter from the center line of the insert gradually decreasing toward the tip side, the hard surface layer is coated on the insert body from a surface of the end portion of the insert body to an outer periphery of the intermediate portion, and an outer diameter of the hard surface layer on the intermediate portion is equal to that of the rear end portion.

Abstract: A rotary cutting tool including a polycrystalline diamond material of the invention includes: a tool body rotated about an axis with a carbide substrate made of cemented carbide and a flute provided at a tip portion thereof; a PCD layer sintered integrally with the carbide substrate, provided on an inside face of the flute facing in a rotation direction; and a cutting edge provided on the PCD layer to have the inside face as a rake face, in which a margin portion continuous with a rear side of the flute in the rotation direction is formed on an outer periphery of the tip portion, the cutting edge is formed at a ridge portion of the rake face, and a thickness of the PCD layer is ? to 1 times a width of the margin portion.

Abstract: A drill bit button insert is attached to a button inserts mounted in a drill bit and performs a drilling. The drill bit button insert includes a tip body and an abrasive layer that is formed of a diamond sintered body harder than the tip body and is coated at least at the button insert working surface of the tip body. The abrasive layer has two or more high hardness layers and a low hardness layer having a hardness lower than that of the high hardness layers disposed between the high hardness layers. The high hardness layers and the low hardness layer are provided from the surface side of the abrasive layer toward the tip body side.

Abstract: A drilling tip according to the disclosure has a tip body which is provided with a tip portion tapered toward a tip side of the tip body; and a hard layer which is formed on a surface of the tip portion of the tip body, an outermost layer of the hard layer is a cBN sintered material having 70 to 95 vol % of cBN grains, and when a cross-sectional structure of the outermost layer is observed, a binder phase having a width of 1 nm or greater and 30 nm or less and containing Al, B, and N, and in which a ratio of an O content to an Al content is 0.1 or less exists between neighboring cBN grains.

Abstract: A polycrystalline diamond sintered material tool includes: a cemented carbide substrate, which is mainly composed of WC and includes Co; and a diamond layer containing a metal catalyst made of Co provided on the cemented carbide substrate. The average layer thickness of a Co rich layer formed in an interface between the cemented carbide substrate and the diamond layer is 30 ?m or less. CMAX/CDIA is 2 or less when CDIA is an average content of Co included in the diamond layer and CMAX is a peak value of a CO content in the Co rich layer. D/DO is less than 2 when D is an average grain size of WC particles in a region from the interface between the cemented carbide substrate and the diamond layer to 50 ?m toward an inside of the cemented carbide substrate; and DO is an average grain size of WC particles.

Abstract: A drill bit insert attached to a tip portion of a drill bit to perform drilling, includes: an insert body (1) that includes: a rear end portion buried in a bit body of the drill bit; and a tip portion protruding from a surface of the drill bit and tapered toward a tip side of the insert body, in which a surface of at least the tip portion of the insert body (1) made of polycrystalline cubic boron nitride compact (4) sintered using a catalytic metal containing Al and at least one selected from the group consisting of Co, Ni, Mn, and Fe and containing 70 vol % to 95 vol % of cubic boron nitride.

Abstract: A polycrystalline tungsten compact, having high density and a fine grain structure is produced by: preparing a raw material powder made of W particles, a raw material powder where W powder and an alloy particle powder of one or more selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and Mn are blended, or a green compact thereof; inserting them in a pressure sintering apparatus; and sintering them in a state where a pressing of 2.55-13 GPa is loaded on the raw material powders or the green compacts at 1200° C. to a melting point. A relative density of the compact is 99% or more, a porosity of the compact measured in an arbitrary cross section of the compact is 0.2 area % or less, an average crystal grain size is 50 ?m or less, and an average aspect ratio of crystal grains is 1 to 2.5.

Abstract: In a drill bit insert of the present invention, an insert body of the drill bit insert includes: a rear end portion forming a columnar shape or a disk-like shape; an intermediate portion having an outer diameter smaller than that of the rear end portion; and an end portion having an outer diameter from the center line of the insert gradually decreasing toward the tip side, the hard surface layer is coated on the insert body from a surface of the end portion of the insert body to an outer periphery of the intermediate portion, and an outer diameter of the hard surface layer on the intermediate portion is equal to that of the rear end portion.

Abstract: A drill bit button insert of the present invention that is attached to a button inserts mounted in a drill bit and performs a drilling, includes a tip body and an abrasive layer formed of a diamond sintered body harder than the tip body coated at least at the button insert working/cutting surface of the tip body, in which the abrasive layer has at least two high hardness layers and a low hardness layer having a hardness lower than that of the high hardness layer disposed between these high hardness layers from the surface side of the abrasive layer toward the tip body side.

Abstract: A rotary cutting tool including a polycrystalline diamond material of the invention includes: a tool body rotated about an axis with a carbide substrate made of cemented carbide and a flute provided at a tip portion thereof; a PCD layer sintered integrally with the carbide substrate, provided on an inside face of the flute facing in a rotation direction; and a cutting edge provided on the PCD layer to have the inside face as a rake face, in which a margin portion continuous with a rear side of the flute in the rotation direction is formed on an outer periphery of the tip portion, the cutting edge is formed at a ridge portion of the rake face, and a thickness of the PCD layer is 1/3 to 1 times a width of the margin portion.