A method for milling a workpiece by way of at least one substantially polygonal cutting insert, which is arranged in a tool holder. A spindle axis of the tool holder encloses an angle of more than 0° with a plane normal to a machined workpiece surface. An effective lead angle between a main cutting edge of the cutting insert and the machined workpiece surface lies between 0° and 20°.

Ceramic end mill with cutting edge portion including gashes between cutting edges and adjacent in a rotation direction. Center cut edges are formed at end cutting edges close to and facing rotation axis O. Center grooves are formed on rear sides of center cut edges and end cutting edges in the rotation direction continuous with a radial direction. The center grooves are continuous with positions where end cutting edge second surfaces face or approach rotation axis O. End cutting edge second surfaces are laid between center cut edges and end cutting edges. Center grooves are formed between end cutting edge second surfaces and center cut edges positioned on a rear side of end cutting edge second surfaces in the rotation direction. The center grooves pass on rotation axis O. Center grooves double as rake faces of the respective center cut edges and are continuous with the gashes.

A method for performing a cutting operation on a workpiece is provided. The method comprises providing a workpiece being made of a metal characterized by a thermal conductivity of no greater than about 100 W100 .sup.W/.sub.(m.Math.K) (approximately 57.8 .sup.Btu/.sub.(hr ft ° F.)), providing a cutting device comprising an internal cooling cavity defined on one side thereof by a thin-walled structure, and performing a cutting operation on the workpiece using the cutting device. The cutting speed is no less than about 500 .sup.m/.sub.min. (approximately 1640 .sup.ft/.sub.min).

A mold is configured to resin-seal a semiconductor chip to form a semiconductor package. The mold has a first mold cavity and a second mold cavity formed in the bottom of the first mold cavity with a stepped portion between the two mold cavities. The two mold cavities are formed in succession by a high-speed rotary cutter having a downwardly tapered round cutting surface that imparts a corresponding taper to walls of the two mold cavities.

The subject invention is directed to metal working operations and, more particularly, to machining heat resistant super alloys (HRSAs) such as titanium alloys with polycrystalline diamond cutting inserts sintered on a carbide substrate. Using at least one cutting insert mounted upon a rotary toolholder and wherein the at least one cutting insert has a substrate with a top layer of PCD secured thereto over no less than 1/3 of a substrate top surface, a method of machining heat resistant super alloys (HRSAs) is made up of the steps of rotating the rotary toolholder such that an insert surface speed rate is above 50 meters per minute and adjusting a tool feed rate (advance per tooth per revolution) and/or radial engagement of the toolholder such that the machining operation produces chips having a thickness of approximately 0.050-0.200 millimeters.

A method for milling a workpiece by way of at least one substantially polygonal cutting insert, which is arranged in a tool holder. A spindle axis of the tool holder encloses an angle of more than 0 with a plane normal to a machined workpiece surface. An effective lead angle between a main cutting edge of the cutting insert and the machined workpiece surface lies between 0 and 20.

A cutting insert has an upper surface (21), a lower surface (91) and a side surface (61) that connects the two surfaces. A cutting edge is formed at an intersecting edge between the upper surface (21) and the side surface (61). The cutting edge includes at least a major cutting edge (33), a corner edge (34) connected to the major cutting edge (33), and a curved wiper edge (35) located on the opposite side of the major cutting edge (33) across the corner edge (34). A first angle made by the major cutting edge (33) and the chord of the wiper edge (35) is 155<180, and a positive land is formed in the wiper edge (35). The cutting edge may further include an inner cutting edge (36) located on an opposite side of the corner edge (34) across the wiper edge (35).

A high-speed precision interrupted ultrasonic vibration cutting method includes steps of: (1) installing an ultrasonic vibration apparatus on a machine tool, and stimulating a cutting tool to generate a transverse vibration, so as to realize varieties of machining processes; (2) realizing an interrupted cutting process by setting cutting parameters and vibration parameters to satisfy an interrupted cutting conditions; and (3) turning on the ultrasonic vibration apparatus and the machine tool, and starting a high-speed precision interrupted ultrasonic vibration cutting process. High-speed precision interrupted ultrasonic vibration cutting is able to be realized through the above steps during machining of difficult-to-machine materials in aviation and aerospace fields. A cutting speed is enhanced significantly, and exceeds a critical cutting speed of a conventional ultrasonic vibration cutting method and an elliptical ultrasonic vibration cutting method and even a high speed range of a traditional cutting method.

An indexable cutting insert for face milling with high feed rates has: an upper side, a lower side with a smaller outer circumference than the upper side, and side surfaces connecting the upper and lower sides. Rounded cutting corners are formed at the transition between the side surfaces and the upper side. The cutting corners are connected via convexly arched cutting edges, each running convexly curved from one cutting corner to an adjacent cutting corner. Adjacent the cutting edges, the side surfaces have main flanks extending along the respective cutting edge in a continuously convexly curved manner from one cutting corner to an adjacent cutting corner. The main flanks extend in the direction of the lower side only over part of the height of the side surfaces and merge in a stepped manner into secondary surfaces which are set back inward.

Ceramic end mill with cutting edge portion including gashes between cutting edges and adjacent in a rotation direction. Center cut edges are formed at end cutting edges close to and facing rotation axis O. Center grooves are formed on rear sides of center cut edges and end cutting edges in the rotation direction continuous with a radial direction. The center grooves are continuous with positions where end cutting edge second surfaces face or approach rotation axis O. End cutting edge second surfaces are laid between center cut edges and end cutting edges. Center grooves are formed between end cutting edge second surfaces and center cut edges positioned on a rear side of end cutting edge second surfaces in the rotation direction. The center grooves pass on rotation axis O. Center grooves double as rake faces of the respective center cut edges and are continuous with the gashes.