A toolholder includes a cutting tool mounted to a head attached to a collar at a first end of the toolholder. A shank is located at a second, opposite end of the toolholder. A central cavity extends inwardly from the first end toward the shank. A passive vibration absorber assembly is disposed within the central cavity. The passive vibration absorber assembly includes an absorber body and an absorber cap attached to the absorber body. The absorber body has a first end, a second end opposite the first end, and one or more cavities formed in the second end. The one or more cavities of the absorber body are partially of wholly filled with metal or ceramic particles or powders to provide particle damping for suppressing vibration of the toolholder.

A cutting insert includes a top surface, a bottom surface and a plurality of peripheral side surfaces. The top and bottom surfaces and the side surfaces are joined to form rounded cutting corners. A plurality of cutting edges are formed at an intersection between the top surface and the plurality of side surfaces. A pair of asymmetric chip formers are proximate opposite rounded cutting corners. A distance between the opposite rounded cutting corners and the asymmetric chip formers varies in such a way that a ratio of a chip thickness and the distance is substantially constant as a function of a depth of cut.

A tunable or tuned boring tool having a dynamic vibration absorber is provided herein. The boring tool includes a boring bar having a distal portion configured to support a tool, a proximal portion configured for attachment to a support structure of a metalworking machine, and a cylindrical body extending between the proximal portion and the distal portion, having an elongated cavity therein. The boring tool further includes a tuned or tunable absorber inserted in the cavity of the boring bar. The absorber includes an absorber mass, an annular or partially annular support circumscribing each end of the absorber mass for holding the absorber mass within the cavity, and a layer of fluid restricting material surrounding at least a central portion of the absorber mass for dampening vibration of the absorber mass. A method of forming a boring tool with a dynamic vibration absorber is also provided herein.

A tuned or tunable boring tool includes a boring bar defining an elongated cavity therein. A distal end of the boring bar is configured to support a tool or cutting insert. The boring tool further includes a dynamic vibration absorber inserted within the elongated cavity of the boring bar. The dynamic vibration absorber includes a mass that vibrates in conjunction with vibration of the boring bar. The mass has a proximal end and a distal end. The dynamic vibration absorber further includes at least one resilient proximal support positioned adjacent to and supporting the proximal end of the mass and at least one distal resilient support positioned adjacent to and supporting the distal end of the mass. The at least one proximal support and at least one distal support have a different stiffness.

A cemented carbide consisting of a first hard phase, second hard phases, and a binder phase, wherein the first hard phase is composed of tungsten carbide grains, a D10 and a D90 of grain sizes of the tungsten carbide grains are 0.40 sm or more and 2.00 sm or less respectively, the second hard phases are composed of at least one first compound selected from the group consisting of TaNbC, TaNbN, TaNbCN, TiCN, TiNbC, TiNbN, and TiNbCN, the cemented carbide includes 0.30 to 1.60% by volume of the second hard phases, a median of areas of the second hard phases is 0.90 to 1.20 m.sup.2, a coefficient of variation of the areas of the second hard phases is 0.50 to 1.20, the binder phase includes 50% by mass or more of cobalt, and the cemented carbide includes 8.0 to 12.0% by volume of the binder phase.

An efficient chatter cutting method for a difficult-to-machine material is provided, relating to the technical field of cutting processing. The method includes the following steps: installing a chatter tool bar on a machine tool, starting the machine tool, and inducing self-excited chatter for chatter cutting through cutting energy of a tool system; during chatter cutting, exciting the chatter tool bar to induce stable vibration, making the tool form a ratchet-shaped motion trajectory, the ratchet-shaped motion trajectory includes processes that the tool is pressed on a surface of a workpiece and the tool is separated from the surface of the workpiece, and forming a ratchet-shaped surface morphology on the surface of the workpiece; and during separation of the tool from the surface of the workpiece, enabling cutting fluid to enter a separated cutting zone for cooling and lubrication, and reducing cutting temperature.

A cemented carbide consisting of a first hard phase, second hard phases, and a binder phase, wherein the first hard phase is composed of tungsten carbide grains, a D10 and a D90 of grain sizes of the tungsten carbide grains are 0.40 m and 2.00 m respectively, the second hard phases are composed of at least one first compound selected from the group consisting of TaNbC, TaNbN, TaNbCN, TiCN, TiNbC, TiNbN, and TiNbCN, the cemented carbide includes 0.30% to 1.60% by volume of the second hard phases, a median of a distance between centroids of two of the second hard phases that are closest is 4 to 15 m, a coefficient of variation of the distance between centroids is 1.20 to 1.90, the binder phase includes 50% by mass or more of cobalt, and the cemented carbide includes 8.0 to 14.0% by volume of the binder phase.

A cemented carbide consisting of a first hard phase, second hard phases, and a binder phase, wherein the first hard phase is composed of tungsten carbide grains, a D10 and a D90 of grain sizes of the tungsten carbide grains are 0.40 m and 2.00 m respectively, the second hard phases are composed of at least one first compound selected from the group consisting of TaNbC, TaNbN, TaNbCN, TiCN, TiNbC, TiNbN, and TiNbCN, the cemented carbide includes 0.30% to 1.60% by volume of the second hard phases, a median of a distance between centroids of two of the second hard phases that are closest is 4 to 15 m, a coefficient of variation of the distance between centroids is 1.20 to 1.90, the binder phase includes 50% by mass or more of cobalt, and the cemented carbide includes 8.0 to 14.0% by volume of the binder phase.

A cutting tool has an insert holder and a cutting insert releasably attached thereto. The cutting insert has an insert edge which includes two nose cutting edges and a convex corner cutting edge which extends therebetween. The two nose cutting edges form a nose angle. The insert edge also includes two mid-side edges which are located further from the corner cutting edge than the nose cutting edges. The two mid-side edges form a mid-side angle. The nose angle is less than the mid-side angle.

A lightweight vibration damping cutting tool bar includes a tool body, on which a plurality of cavities are opened along the length direction, and the cutting tool body between adjacent cavities have a BCC lattice structure, the closed magnetic pole device includes a plurality of magnetic pole pieces located at the bottom and side walls of the cavity respectively; the pendulum damper is placed inside the closed magnetic pole device composed of a plurality of magnetic pole pieces, the outer surface of the pendulum damper is provided with a magnetic pole patch corresponding to each magnetic pole piece one by one, the magnetic pole patch is set relative to the side with the same polarity of each magnetic pole piece, so that the magnetic force of each magnetic pole piece and the magnetic force of the corresponding magnetic pole patch are repelled.