Overcoming manufacturing challenges in the fabrication of thin-beam 316L stainless steel lattice cells via material extrusion debinding and sintering

Purpose The purpose of this study is to deal with the manufacturing of six different unsupported thin-beam lattice cells with two beam size (2.0 and 2.4 mm) through material extrusion debinding and sintering (MEX+D&S) technology. Design/methodology/approach Printing thin and complex structures remains challenging with this multistep additive manufacturing (AM) processes. In this study, beam-based and unsupported lattice cells were designed, printed, debound and sintered using a commercial 316L stainless steel filament and a consumer 3D printer. First, shrinkage was evaluated at both the beam and the cell level, using the data obtained from a 3D structured light scanner. In addition, the same structures underwent compression testing to validate their mechanical response. Findings Six different unsupported lattice cells characterized by bridges and overhang features were successfully printed after a specific definition of printing parameters. One of them collapsed during debinding due to the combination of residual stress and absence of support. The shrinkage of the beam tended to increase when the angle between the beam and the printing bed increased. Cells with 2.4 mm of beam diameter revealed better compression strength, whereas the 2.0 mm counterpart showed the highest specific elastic modulus. Originality/value The demand for lightweight solutions has driven the widespread adoption of AM for the realization of complex structures. MEX+D&S offers a viable alternative to the widely used laser-based technologies for the realization of metallic parts, thanks to their ease of use and lower costs.