Cemented carbide ball end mill

Abstract

A cemented carbide ball end mill comprises a cutting portion with a semi-spherical ball portion at a tip thereof, and has a following configuration. When an intersection line between a cutting edge rake face and a chip evacuating flute at the ball portion is projected on a plane which includes a central axis of the ball end mill and is parallel with a cutting edge at the central portion of a ball portion tip, projected on the plane is a convex-curved line or a straight line. An angle formed by the straight line connecting a vertex of the ball portion, where the intersection line passes through, and the other end of the intersection line with respect to the central axis is from 30° to 50°. Further, an angle formed by the rake face and the chip evacuating flute is from 100° to 150°, and a width of the chip evacuating flute is 0.5 to 5 times as large as a radius of the ball portion. On the cutting portion, a coating film of titanium carbide or the like is formed as a first layer, and another coating film of a silicon carbide system amorphous film or the like having a physical property similar to that of diamond is added as a second layer. The cemented carbide ball end mill suffers less deposition of melted metal even when dry-cutting an aluminum alloy, has a long service life, and enables the machining providing an excellent surface property.

Dependencies are inferred from the claim text.