Laser additive manufacturing of bio-inspired lattice structure: Forming quality, microstructure and energy absorption behavior

Development of additive manufacturing technology effectively extends the design and application of novel lattice structures. A novel lattice structure, inspired from the beetle's front wing, was designed and fabricated by selective laser melting to investigate the effects of processing parameters on densification behavior, microstructure and mechanical properties. The lattice structure exhibited high densification (>97%) at the optimized processing parameters. As the laser power increased, the transformation from the cellular dendritic to the columnar dendritic was observed, simultaneously accompanying the grain coarsening. The load-displacement curves of all lattice structures exhibited three characteristic deformation stages: (i) the elastic deformation; (ii) the inhomogeneous plastic deformation; (iii) the failure/breaking. During the compressive process, the successive transfer of stress concentration from the intersections of the horizontal struts to the intersections of the diagonal struts occurred. At the optimized processing parameter (P = 375 W, v = 3500 mm/s), the lattice structure exhibited excellent energy absorption capability (3.45 J) with high bearing force (2.95 kN) and large displacement (1.18 mm).