Effects of process parameters on material side flow during hard turning

The phenomenon of material side flow represents an important aspect of mach ined surface quality during hard turning. In this paper, an experimental st udy was performed to investigate the main features of this phenomenon. The effects of process parameters including edge preparation, nose radius, feed and tool wear on material side flow were examined. Two possible mechanisms for material side flow were investigated. In the first one, the material i s squeezed between the tool flank face and the machined surface when chip t hickness is less than a minimum value. In the second mechanism, the plastif ied material in the cutting zone flows through the worn trailing edge to th e side of the tool. Both of these mechanisms can exist simultaneously. The results obtained from surface examination showed a strong correlation betwe en edge preparation and material side flow. An increase in the tool nose ra dius resulted in a remarkable increase of material side flow. Feed had an i ndirect effect on material side flow. In addition, tool wear significantly affected the existence of material side flow on the machined surface. An in crease in tool wear promoted the occurrence of material side flow. (C) 1999 Elsevier Science Ltd. All rights reserved.