Experimental and Numerical Study of Media Action During Tribofinishing in the Case of SLM Titanium Parts

Tribofinishing is an ancient and widely used process in industry. However the preparation to reach this steady state is long and costly and the know-how is mainly based on the long experience of the providers (machine builder and abrasive media producer), whereas the literature to help end-users is very limited. Moreover is difficult to understand the phenomena during media action, particularly at the interface between the piece and the abrasives. The objective of this paper is to present the design of a new experimental set-up that enables the characterization of tribofinishing conditions. The system is based on a CNC milling machine dragging a part in a large volume of abrasive media (i.e. drag finishing). This new set-up has been used to investigate the influence of various abrasive media (size and geometry) on the evolution of the surface roughness along the surface of titanium parts obtained by SLM (selective laser melting). In parallel, a discrete element model of the set-up has been developed in order to identify the local contact conditions between abrasive media and the part, which enable to understand the local physical phenomena in mass finishing.