Near-circular EDM hole drilling for deterministic cellular lattice structures of LPBF IN718

• Published in: Materials letters 2023-11, Vol.350, p.134886, Article 134886
• Main Authors: Singh, Mahavir, Gusain, Sumit, Kumar Mishra, Sarvesh, Ramkumar, Janakarajan, Gomez Escudero, Gaizka, Gonzalez Barrio, Haizea, Calleja Ochoa, Amaia, Norberto Lopez de Lacalle, Luis
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Electrical discharge machining; Laser powder bed fusion; Laser processing; Lattice structures; Porous materials
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2023.134886

[Display omitted] •Deterministic cellular lattice structures of IN718 are fabricated through LPBF.•Through-holes EDM drilling is performed on LPBF-fabricated lattice structures.•Machined holes show dimensional variability due to pores, nodes, and lattice defects.•Near-circular through-holes machined by optimizing EDM parameters and electrode positioning. Additive manufactured (AM) metallic lattice structures are being largely explored for different engineering applications. The fastening, implantation, and installation of such lattice structures demand secondary processing. In the current work, through-hole drilling is performed using electrical discharge machining (EDM) on Inconel 718 (IN718) lattice structures fabricated by laser powder bed fusion (LPBF). The challenges in EDM hole drilling have been encountered and uncertainty in the machined holes owing to periodically open pores and nodes in the lattice structures sizes has been identified. Finally, an experimental strategy has been proposed for near-circular hole drilling by design optimization and tool positioning with respect to the cellular structures.