Technological and sustainability implications of wet and dry turning of Ti6Al4V EBM parts

Abstract

Sustainability is a crucial topic nowadays and Additive Manufacturing (AM) processes are becoming more and more widely used today also because, among its advantages, is claimed to be green technology. However, AM parts usually require postprocessing to improve their surface finishing and result assemblable. In this study, a Ti6Al4V cylindrical sample has been manufactured by Electron Beam Melting (EBM) and then post-processed by turning. Both dry and wet turning has been performed by using the same process parameters. Surface roughness has been measured both before and after each turning pass along the parallel and perpendicular direction to the cylindrical axis and energy consumption has been recorded during each turning pass. Results showed that both dry and wet turning led to a lower roughness along the perpendicular direction to the cylindrical axis than that along the parallel direction, as a result of the technological signature of the turning process. Also, they depict that the first turning pass results in higher cutting forces and, then, the highest values of energy consumption among all the turning passes, both in wet and dry turning. The Specific Energy Consumption (SEC) index has been investigated to evaluate the energy required to remove a unit volume of material; it reflects lower cutting efficiency in the material removal process.