EXPERIMENTAL INVESTIGATION ON TOOL WEAR DURING THE MILLING PROCESSES FOR THE POST-PROCESSING OF SELECTIVE LASER MELTED INCONEL 718 ALLOYS

摘要

The importance of the post-processing is increasing to remove the supporter afterward the additive manufacture process. The machining, known as the material removal process, achieve the high efficiency and rapid process as compared with the others techniques. This paper experimentally investigated the tool wear during the milling operations of the additive manufactured workpieces for the post-processing. The XRD analysis resulted that Inconel 718 powder used in the additive manufacturing has crystal structure FCC, which homologies the chemical compositions in wrought Inconel 718. The selective laser melting process had built the additive manufactured samples with two different orientations. Wrought Inconel 718 was the lowest hardness among the workpieces, whereas the severe tool wear was observed during the milling operation of wrought Inconel 718. The defects as the pores and cavities in the additive manufactured parts lead the low tool wears, even though the high hardness on the surfaces of the SLM Inconel 718. Further, the built orientation dominated the re-melted zone in the SLM parts, the contact between the tool and re-melted zone controlled the tool wears. Therefore, it should consider the built orientations to apply the machining as the post-processes.