Energy saving in milling of electron beam–melted Ti6Al4V parts: influence of process parameters

Abstract

Additive manufacturing (AM) is claimed to be a green technology because of its potential in improving material use efficiency. Electron beam melting (EBM) is among the most popular AM techniques adopted to manufacture titanium parts for medical and aerospace applications, as the technology offers an effective way of producing lightweight and complex parts. Nevertheless, additively manufactured parts hardly ever meet industrial quality standards, so post-treatments are always required resulting in additional resources and energy consumption. Moreover, still few works exist on joint analysis of energy consumption and roughness in milling EBMed parts by means of a non-typical tool, and this study aims to fill this gap of knowledge. Three EBM Ti6Al4V cylindrical samples were manufactured into a single job of the ARCAM A2X machine in the same process conditions. Three lengths, 120° apart from each other, were defined along the direction parallel to the axis of each cylinder to perform the milling by varying spindle speed, depth of cut, and machining speed. A high-performance complex-shaped insert has been used to perform the milling process to improve the surface finishing of the Ti6Al4V EBMed samples. Total energy consumption has been calculated as the sum of the machining time and the non-machining time. A joint investigation of both the surface roughness and the energy consumption in machining led to understanding which the best cut strategies are to perform milling with a complex cutting tool from a sustainability perspective. Results showed that it is not sustainable to choose the minimum depth of cut to obtain a fixed total depth of material removed as non-machining time showed to play a crucial role in the total energy consumption of the milling process.