Phenomenological analysis of material side flow in hard turning: Causes, modeling, and elimination

Material side flow causes surface damage that has been observed and partly investigated over a period of several years. This paper presents a phenomen ological analysis of material side flow in hard turning. First, material si de flow is identified, characterized, and its causes classified. Then, the dependence of the material side flow on different process parameters is ana lyzed using the results of a comprehensive experimental investigation. Tool nose radius, tool wear, and feed are considered as the primary factors tha t initiate the occurrence of material side flow in finish turning of harden ed steel. A new concept for modeling material side flow is then proposed. T his model predicts the minimum chip thickness that allows the workpiece mat erial in the vicinity of cutting to plastically flow at the side of the too l, instead of shearing. The value of the minimum chip thickness affects the size of material side flow on the feed marks. Based on the results obtaine d from the model, the feed and tool nose radius that eliminates/minimizes m aterial side flow in hard turning are specified.