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 (112) comprising a top surface (118), a bottom surface (120), and side surfaces (122) spanning there-between, said side surfaces (122) comprising one or more feed-facing side surfaces (122a) and one or more radial-facing side surfaces (122b). The top surface (118) is formed with one or more linear grooves, each constituting a chip breaker (125) and being disposed parallel to and adjacent one of said feed-facing side surfaces (122a). The chip breaker (125) is characterised by a constant profile along the entire length of its respective feed-facing surface (122a). Each of said feed-facing side surfaces (122a) is disposed at an acute feed-angle ( feed) with respect to the top surface (118), and each of said radial-facing side surfaces (122b) being disposed at an acute radial-angle ( radial) with respect to the top surface (118), the feed-angle ( feed) being greater than said radial-angle ( radial).

A cutting tool according to an aspect of the present disclosure includes a cutting edge portion which contains at least one of cubic boron nitride and polycrystalline diamond. The cutting edge portion includes a rake face, a flank face, and a cutting edge. The flank face is contiguous to the rake face. The cutting edge is provided as a ridge line between the rake face and the flank face. The radius of curvature of the cutting edge is 2 m or more and 8 m or less.

It is intended to allow a wide range including a low region (fine finishing) to a middle region (medium cutting) to be covered with a single insert. A cutting insert includes an upper surface, a lower surface, a peripheral side surface, a cutting edge including a main cutting edge and a corner cutting edge, a corner portion, a projecting portion formed to extend from the corner portion toward a central axis and including a first projection and a second projection, a rake portion, and an inclined portion provided at the cutting edge. The inclined portion has a first inclined portion beginning at an intermediate point in the corner cutting edge, while the rake portion has a shape in which an angular degree of a rake angle gradually increases with distance from the corner portion.

A cutting insert may include a first surface, a second surface, a third surface, and a land surface. The first surface may include a first corner and a first side. The land surface may be located between the first surface and the third surface. The land surface may include a first land surface connecting to the first corner, and a second land surface connecting to the first side. A width of the first land surface in a front view as viewed from a side of the first surface may be a first width, the first width at an end portion on a side of the second land surface may be larger than the width at a part connecting to a midportion of the first corner.

A cutting insert may include a first surface, a second surface, a third surface and a cutting edge. The first surface may include a corner, a first side, a first inclined surface located along the corner, a second inclined surface located further inside than the first inclined surface, a third inclined surface located along the first side, a fourth inclined surface located further inside the first surface than the third inclined surface, and a protruded part located further inside than the second inclined surface and the fourth inclined surface. An inclination angle of the protruded part may be smaller than an inclination angle of the second inclined surface in a cross section along a bisector of the corner. The inclination angle of the protruded part may be larger than a third inclination angle in a cross section orthogonal to the first side.