Additive manufacturing (AM) is a novel technique that enables rapid production of net-shaped components with complex geometries such as lattice structures with high energy absorption capacity. Laser powder bed fusion (LPBF) stands out as one of the most feasible AM techniques for the production of lattice structures due to its relatively high resolution (small laser spot size), which allows production of filigree structures. High design flexibility provided by LPBF also allows manipulation of the mechanical response of lattice structures through topology and cell design.

As a member of second generation advanced high-strength steels (AHSS), high-manganese steels (HMnS) have been reported as promising alloys being suitable for the production of lightweight lattice structures. By addition of Al in different amounts (1 and 5 wt.%) to a single-phase austenitic steel (X30Mn22 base alloy), different mechanisms, i.e., transformation-induced plasticity (TRIP), twinning-induced plasticity (TWIP), can be activated to manipulate the strain-hardening behaviour. X30Mn22, X30MnAl22-1, and X30MnAl22-5 lattice structures with f₂cc,z cells show higher weight-specific energy absorption compared to benchmark materials such as Ti6Al4V and AISI 316L alloys. Furthermore, a new geometrical design of the lattices was proposed in order to prevent strain localisation at the nodes of the structures under load while also improving the microstructural and mechanical characteristics. In this contribution, the combined alloy and geometry design approach for HMnS lattice structures with enhanced energy-absorption capacity is presented.