A method of forming an aperture in a ceramic matrix composite material is provided. The method may comprise drilling a pilot hole into the ceramic matrix composite material and spiral machining the pilot hole to enlarge a diameter of the pilot hole, wherein the enlarged pilot hole is the aperture in the ceramic matrix composite material. The method may comprise spiral machining the pilot hole in a radial direction with a tool to enlarge a diameter of the pilot hole until the aperture in the ceramic matrix composite material is formed. The tool may have a first diameter in a section of the tool and a second diameter on either side of the section of the tool or on both sides of the section of the tool, wherein the second diameter is larger than the first diameter.

A single-crystal diamond having a first facet plane is prepared. The single-crystal diamond is fixed to the support based on the first facet plane. An X-ray image of the single-crystal diamond is captured, the X-ray image being an X-ray image in which a crystal orientation of the single-crystal diamond is associated with an X-ray emission direction by associating the support to which the single-crystal diamond is fixed with the X-ray emission direction. A position of an inclusion of the single-crystal diamond in the single-crystal diamond is specified based on the X-ray image. It is determined whether or not a shape of the diamond tool intermediate is extractable from the single-crystal diamond with the inclusion being not included in an inclusion-excluded region. The shape of the diamond tool intermediate is extracted from the single-crystal diamond with the inclusion being not included in the inclusion-excluded region.

A drill bit, formed of a a drill blank and a drill body. The drill body includes multiple outer projections and outer wall channels and multiple inner projections and inner wall channels, where the inner wall channels are formed as back sides of the outer projections and the inner wall channels have complementary shapes to the shapes of the outer projections, and the outer wall channels are formed as the backside of the inner projections, and the outer wall channels have complementary shapes to the shapes of the inner projections, where the outer projections and outer wall channels are distributed around a circumference of the drill body, and wherein each of the outer projections and outer wall channels include at least one curved parts therein.

A method for manufacturing a cutting tool according to one embodiment is a method for manufacturing a cutting tool, the cutting tool including a base material and a diamond single crystal material fixed to the base material, the diamond single crystal material having a rake face, a flank face continuous with the rake face, and a cutting edge formed by a ridgeline serving as a boundary between the rake face and the flank face. The method for manufacturing a cutting tool according to one form of the present disclosure includes a flank face irradiation step of applying a laser to the diamond single crystal material along the cutting edge from a side of the flank face. The laser has a pulse width of 110.sup.12 seconds or less and a peak output of less than 1 W in the flank face irradiation step.

A laser-transmitting machining tool is disclosed. The laser-transmitting machining tool has a plurality of faces including an entrance face, a rake face, a flank face connected to the rake face, a rake side face extending between the entrance face and the rake face, and a flank side face extending between the entrance face and the flank face. The connection of the rake face to the flank face defines a cutting edge. The rake face extends away from the rake side face to define a rake angle. The entrance face is configured to receive and refract a laser beam to the rake face, the flank face, and the cutting edge for causing the laser beam to refract into and heat the workpiece at a compression region extending proximate at least the rake face and a tensile region extending proximate the flank face. A system for machining a workpiece is disclosed. A method for machining a workpiece is also disclosed.

In a general aspect, a machining tool includes a diamond crystal having a working section configured to machine a workpiece. The machining tool includes a body and a shank extending from the body. The shank defines a cylindrical slot outside the body. The machining tool includes an assembly carried by the shank. The assembly includes a cylindrical pin that resides in the cylindrical slot. The assembly also includes a diamond crystal secured to an end of the cylindrical pin. The diamond crystal has a curved perimeter that defines a working section, which contacts a workpiece during operation of the machining tool. The shank is adapted to allow rotation of the cylindrical pin within the cylindrical slot to modify the working section.

A turning tool includes: a holder portion; and a cutting edge portion fixed to the holder portion, wherein the cutting edge portion is composed of a synthetic single-crystal diamond, and the cutting edge portion has a nose curvature having a curvature radius of more than or equal to 0.1 mm and less than or equal to 1.2 mm, and the nose curvature satisfies at least one of a condition that a direction of a line of intersection between the rake face and a bisecting cross section of a vertex angle of the nose curvature is within ?10? relative to a <110> direction of the synthetic single-crystal diamond, and a condition that the direction of the line of intersection between the rake face and the bisecting cross section of the vertex angle of the nose curvature is within ?10? relative to a <100> direction of the synthetic single-crystal diamond.

A diamond coated tool includes a base material and a diamond layer provided on the base material. The diamond layer has a boron content of 1?10.sup.3 ppma or more and 1?10.sup.6 ppma or less and an oxygen content of 1?10.sup.2 ppma or more and 1?10.sup.5 ppma or less in a first region surrounded by a surface of the diamond layer and a first imaginary plane located at a distance of 1 ?m from the surface in a thickness direction.

A sintered material includes diamond grains and a binder. A boron concentration in the diamond grains is more than or equal to 0.001 mass % and less than or equal to 0.9 mass %. A boron concentration in the binder is more than or equal to 0.5 mass % and less than or equal to 40 mass %.

A composite sintered material includes: a plurality of diamond grains having an average grain size of less than or equal to 10 m; a plurality of cubic boron nitride grains having an average grain size of less than or equal to 2 m; and a plurality of aluminum oxide grains having an average grain size of less than or equal to 0.5 m; and a remainder of a binder phase, wherein at least parts of adjacent diamond grains are bound to one another, the binder phase includes cobalt, in the composite sintered material, a content of the diamond grains is from 30 to 92 volume %, a content of the cubic boron nitride grains is from 3 to 40 volume %, a content of the aluminum oxide grains is from 2 to 15 volume %, and a content of the cobalt is from 3 to 30 volume %.