Frictional interactions between chip and rake face in continuous chip formation

A transparent sapphire cutting tool is used to study directly the frictional interactions occurring at the chip–tool interface. The investigation deals with the orthogonal cutting of single phase, face-centred cubic materials, in air and in vacuum. The investigation brings out two points of importance. First, although there is intimate contact between the chip and the tool in the immediate vicinity of the cutting edge, there is relative movement at the chip–tool interface with little or no adhesive transfer of chip material in this region. Secondly, in each of the systems examined it was found that oxygen increased the cutting forces. This increase was associated with the gross transfer of chip material onto the cutting tool at some distance away from the cutting edge.