Tool Edge Roundness and Stable Build-Up Formation in Finish Machining

Abstract

The results of cutting force measurements when machining materials which do not form a sizable unstable built-up-edge are compared with the results of a theoretical analysis. This analysis, based partly on the use of circular cylindrical surfaces of velocity discontinuity around the base of the tool, yields specific energy values which are uniquely determined by the value of the undeformed chip thickness in relation to the tool edge radius.

From large-scale to micromachining: A review of force prediction models

“…Connolly and Rubenstein (1968), Rubenstein (1990) and Endres et al (1995) assumed full recovery and Abdelmoneim and Scrutton (1973) considered partial recovery. According to Albrecht (1960) and Abdelmoneim and Scrutton (1974), the ploughed layer does not recover. In fact, Abdelmoneim and Scrutton (1974) assumed a slip line field that does not satisfy the principle of volume constancy.…”

“…According to Albrecht (1960) and Abdelmoneim and Scrutton (1974), the ploughed layer does not recover. In fact, Abdelmoneim and Scrutton (1974) assumed a slip line field that does not satisfy the principle of volume constancy. Considering the plastic deformation of the work material at the tool tip and volume constancy, the height of the recovery must be complete.…”

A Slip-Line Field for Ploughing During Orthogonal Cutting

“…A finite radius on the cutting edge was believed to be responsible by contributing additional forces as some material was directed downward below the edge and pressed into the workpiece. Although the discovery of a secondary shear zone at the tool-chip interface changed the view of friction at that interface, ploughing and its importance in cutting became the subject of a number of investigations (Palmer and Yeo, 1963;Johnson, 1967;Moneim and Scrutton, 1974;Heginbotham and Gogia, 1961) and continue to be studied (Rubenstein, 1990;Zhang et al, 1991;Sawar and Thompson, 1981;Parthimos et al, 1993;Wu, 1988;Endres et al, 1995;Elanayar and Shin, 1994) as researchers attempt to gain a complete understanding of the mechanisms of the cutting process. For example, a size effect on cutting forces has long been observed, in which the ratio of forces to the area of cut increases as uncut chip thickness decreases.…”

“…Rubenstein and others (Rubenstein, 1990;Haslam and Rubenstein, 1970;Connolly and Rubenstein, 1968) describe an extrusion-recovery mechanism in which a thin layer of material initially at a depth h (see Figure 1) above the level of the bottom of the cutting edge is extruded below the edge and recovers back to its original level. The material is thought to have a separation point S on the cutting edge at a critical rake angle as, estimated to be around 70 .…”

Slip-line metal cutting model with negative rake angle

“…The increase in F t /F c can only be accounted for by the friction angle increasing as uncut chip thickness decreases. Abdelmoneim and Scrutton (1974) denoted that cutting forces rise as negative rake angle becomes more negative. Günay et al (2004) studied the effects of cutting speed and negative rake angle on cutting forces.…”