In a diamond-coated tool, a flank face of a tool base material includes a first flank face continuously extending to a cutting edge, a second flank face located farther away from the cutting edge than the first flank face and located outside the first flank face when viewed from an inside of the tool base material, and a flank face-side stepped portion connecting the first flank face and the second flank face. A diamond-coated layer is provided on the first flank face and the flank face-side stepped portion.

A cutting insert includes a bottom surface, a top surface opposite to the bottom surface, and a cutting edge portion. The cutting edge portion is located on the same side as the top surface. The cutting edge portion is formed of a sintered material including cubic boron nitride particles. A volume ratio of the cubic boron nitride particles to the sintered material is more than or equal to 50 percent. The cutting edge portion includes a rake face, a flank face contiguous to the rake face, and a cutting edge located along a ridgeline between the rake face and the flank face. The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge.

A cutting insert includes a bottom surface, a top surface opposite to the bottom surface, and a cutting edge portion. The cutting edge portion is located on the same side as the top surface. The cutting edge portion is formed of a sintered material including cubic boron nitride particles. A volume ratio of the cubic boron nitride particles to the sintered material is more than or equal to 50 percent. The cutting edge portion includes a rake face, a flank face contiguous to the rake face, and a cutting edge located along a ridgeline between the rake face and the flank face. The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge.

A gradient wettability tool and a fabrication process thereof are disclosed, the gradient wettability tool comprising a tool body and a lyophobic layer arranged on a surface of the tool body. A lyophilic micro-texture is arranged on a part of a surface of the lyophobic layer, and comprises main trapezoid grooves, a wide end of which is arranged in a tool-chip interface of the tool with a distance of 1 to 200 m from a midpoint of the wide end of the groove to a cutting edge of the tool, and inward-radiated trapezoid microgrooves, a wide end of which is arranged to be connected to a narrow end of the main trapezoid groove. The gradient wettability tool allows directional transport of a cutting fluid and reduction of friction forces at tool-workpiece and tool-chip interfaces, and thus provides wear reduction.

Provided is an external cooling texture turning tool component and a turning process system for coupling nanofluid minimum quantity lubricant with a micro-texture tool. The external cooling texture turning tool component comprises an external cooling turning tool handle and an external cooling turning tool blade; the external cooling turning tool blade is arranged at one end of the external cooling turning tool handle serving as a bearing device; an external cooling turning tool pad is arranged between the external cooling turning tool blade and a structure of the external cooling turning tool handle bearing the blade; an external cooling turning tool pressing plate part is further arranged on the external cooling turning tool handle; the external cooling turning tool blade is tightly pressed on the external cooling turning tool handle by the external cooling turning tool pressing plate part.

A cutting insert 2 includes an upper surface 6, a lower surface 7 on a side opposite to the upper surface 6, and a peripheral side surface 8 connecting the upper surface 6 and the lower surface 7. A cutting edge 61 is formed in at least a part of a first ridgeline 60 where the upper surface 6 and the peripheral side surface 8 intersect. At least one bottomed recess 10 recessed from the lower surface 7 to the upper surface 6 is formed in an outer peripheral portion of the lower surface 7. Each of the recesses 10 is formed in a substantially triangular shape having a first vertex P, a second vertex Q, and a third vertex R. The first vertex P and the second vertex Q are respectively positioned on a second ridgeline 70 where the lower surface 7 and the peripheral side surface 8 intersect. The third vertex R is positioned on the lower surface 7 and separated from the second ridgeline 70.

The edge portion includes an upper surface, a side surface, and a land surface. The side surface has a front side surface and a pair of lateral side surfaces. An intersection between the land surface and the front side surface forms a front cutting edge. An intersection between the land surface and each of the pair of lateral side surfaces form a corresponding one of a pair of lateral cutting edges. The edge portion contains 80 vol % or more of diamond. A chip breaker recess is provided between the upper surface and the land surface. The surfaces forming the chip breaker recess include a rake face and a breaker wall surface. The upper surface has a front edge portion opposite to the front cutting edge from the chip breaker recess. A pair of protruding portions are provided to extend from the front edge portion toward the front cutting edge.

A cutting insert has cutting edges having the same shape and provided at respective corners of a polygon in rotational symmetry about the center axis of the polygon, is clamped in an upright position to a holder, and has a negative side rake angle on a rake face of a side cutting edge. A side cutting edge is present at an intersection ridge between a polygonal face and an outer peripheral face. The outer peripheral face includes a rake face of the cutting edge and a flank of an end cutting edge of another cutting edge different from the side cutting edge. The flank has a positive slope angle in opposition to a negative side rake angle of the side cutting edge. A breaker groove extending in a front-rear direction is formed in the rake face and cuts into the flank, in such a manner as to divide the rake face.

The invention relates to a carrier tool (1) comprising a clamping element (2) with a clamping element projection (3) and comprising a cutting insert (4) with a clamping recess (5) on the cutting insert surface (13) for machining workpieces. The clamping recess (5) has an annular indentation (9) with a recess base (7), and the indentation (9) transitions from the recess base (7) into the cutting insert surface (13) via an annular surface (8). The indentation (9) surrounds an elevation (10), the tip (11) of which lies above the recess base (7) and below the cutting insert surface (13). The clamping element projection (3) engages into the clamping recess (5) and thus clamps same on the carrier tool (1). In order to allow a pre-centering of the contour of the clamping element projection (3) and the contour of the clamping recess (5) when closing the clamping element (2), the contours of the clamping element projection and the clamping recess thus engaging into each other in a form-fitting and precisely positioned manner, the clamping element projection (3) has an annular contour (12) which surrounds the elevation (10) in the clamped state but does not contact the elevation and rests solely on the annular surface (8).

An object is to prolong the life of a cubic boron nitride cutting tool used for cutting a heat-resistant alloy. A cubic boron nitride cutting tool includes an edge tip made of a sintered cubic boron nitride compact including cubic boron nitride particles; and a base metal that holds the edge tip at a corner portion of the base metal, wherein a cutting edge formed on the edge tip of the tool has a positive rake angle.