A method for machining a material, in particular steel, is provided. The material is milled at such a high cutting speed that residual tensile stresses close the surface that exceed a specified value can occur and the residual tensile stresses can be lowered below the specified value by subsequent brushing. A device for performing the method is also provided.

A high-feed milling tool assembly includes a tool and a ramping insert. The ramping insert includes ramping, feed and side sub-edges. The ramping and feed sub-edges are longer than the side sub-edges and converge with increasing proximity to the side sub-edge to which they are both connected.

A method of milling an engine bore is disclosed. The method may include inserting a milling tool having a plurality of cutting edges along a longitudinal axis into an engine bore, rotating the milling tool about the longitudinal axis and moving the milling tool around a perimeter of the engine bore to remove material from the engine bore, and rough honing the bore. The milling may generate a tapered bore (e.g., frustoconical). The rough honing process may increase a minimum diameter of the tapered bore by at least 60 m. A total time of the milling and honing process may be less than 60 seconds. In one embodiment, the honing step may include using a grit size of at least 200 m and/or using a honing force of at least 200 kgf. The method may reduce the cycle time and tooling requirements of forming engine bores.

A high-feed milling tool assembly includes a tool and a ramping insert. The ramping insert includes ramping, feed and side sub-edges. The ramping and feed sub-edges are longer than the side sub-edges and converge with increasing proximity to the side sub-edge to which they are both connected.

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.

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).