Influence of exit angle and tool nose geometry on burr formation in face milling operations

Abstract

One of the more important burrs produced in a face milling operation is the burr formed on the exit edge in the cutting direction. This burr is present over the full length of the exit edge, and under certain cutting conditions is relatively large in size, strongly attached to the workpiece, and presents a strong configuration, features that make it difficult to remove and consequently increases the cost of the component. This paper is concerned with the influence of the exit angle and tool nose geometry on the formation of this burr for both finishing and roughing conditions (small and large depths of cut respectively), with a medium carbon steel. The results show that four different types of burr can be produced on the exit edge, namely the tear, curly, rubbing and wavy burrs. The exit angle and the tool nose geometry have a significant influence on the formation and characteristics of the burr formed on the exit edge. Under finishing conditions, exit angles greater than 90° and large tool nose radii facilitate the formation of large primary burrs. Under roughing conditions, on the contrary, the exit angle affects the type of burr produced on the exit edge, whereas the tool nose geometry only influences the burr size. The formation of primary and secondary burrs is mainly determined by the chip flow angle ρ; primary (wavy) burrs usually form for ρ > ρt (where the transition chip flow angle ρt ≈ 42°, in this case) and secondary (tear) burrs for r < rt.

Burr formation in face milling of cast iron with different milling cutter systems

“…The primary burr protruded from the machined part and became more pronounced; hence their lengths were controlled throughout the tests. Olvera and Barrow [11] reported an increase in burr length with increasing exit angles (from 308 to 1508). In this study the maximum burr length was found at an exit angle, m , of 908.…”

“…This process is highly a ected by the depth of cut, exit angle of the milling cutter and tool geometry. Increase in the depth of cut beyond 0.4 mm reduces the loss of material at the secondary burr, consequently reducing the size of the primary burr [11]. The objective of this work is to study the formation of burr at the exit region of the workpiece, the surface quality and their relation to tool wear.…”

Improvement of workpiece quality in face milling of aluminum alloys

“…In their study, increasing radial rake angles lead to a reduction in burr formation. A considerable influence of the axial rake angle on burr formation was not found (Olvera and Barrow, 1998). In comparison to up milling, down milling is to prefer concerning burr reduction (Olvera and Barrow, 1996).…”

Machining Burrs Formation & Deburring of Aluminium Alloys

“…Longer burrs in the cutting direction are formed when larger corner radii are used. Olvera and Barrow [40] found that the exit angle and the depth of cut influence the exit burr in the cutting direction, whereas the depth of cut is the main factor affecting the exit burr in the feed direction. According to [41,42], the use of high levels of axial depth of cut increases the possibility of burr size minimization, but may also cause inevitable damage to the cutting tool, the machine and machined part functionality.…”