Effects of the tool edge design on the roughness of face milled surfaces

Abstract

Increasing the cutting speed and/or the feed rate is often chosen to increase the efficiency of the material removal. Of course, there are limits to the selection of specific values in both cases, such as, the rigidity of the machining system, the loadability and lifetime of the cutting edges, the prescribed roughness values of the surfaces, etc. When increasing the feedrate in face milling, the conditions of the chip removal change considerably, because at low feed values, the material forming effect of the side edge (i.e. the edge on the lateral surface of the tool) is the most determinative and the chip deforms perpendicular to it, while increasing the feed gradually moves the determinative part of the chip removal to the edge which lies perpendicular to the tool axis. Therefore, both of the two edges have a distinct role in chip removal due to both their position and geometry. The two edges are located on one cutting insert; therefore, their geometry needs to be examined individually and collectively in the search for the most suitable for effective chip removal. The study investigates how the different tool geometrical characteristics affect the roughness parameters of surfaces in normal and in high-feed face milling.