The effect of cutting edge geometry, nose radius and feed on surface integrity in finish turning of Ti-6Al4V

While the respective effects of nose radius, feed and cutting edge geometry on surface integrity have each been studied at depth, coupling between these effects is not yet sufficiently understood. Recent studies have clearly established that cutting edge micro-geometries may not only have positive effects on tool-life, but can also be used to tailor surface integrity characteristics, such as surface roughness and near-surface severe plastic deformation. To further a more fundamental understanding of the effects of cutting edge micro-geometries on surface integrity, experimental turning data was generated for a varied range of cutting tool geometries and feeds. Scanning laser interferometry was used in conjunction with a recently developed profile-analysis algorithm to analyze, characterize, and verify the geometry of complex cutting edge micro-geometries. Near surface nanostructure, and surface roughness of the produced surfaces were characterized and correlated to the varied tool geometries. An interaction between two geometry characteristics, predicted kinematic roughness and hone size, was discovered. Scanning laser interferometry analysis of the surfaces revealed that large hones provided either an increase or decrease in roughness, depending on predicted kinematic roughness.