Laser-Powder Bed Fusion (L-PBF) is a widely used technology that enables the manufacture of complex metallic components while overcoming some of the design constraints of traditional subtractive methods. Recent advances in L-PBF include the fabrication of metal multi-material structures, which allows for tailored and functionally graded properties within a single component. Functionally graded lattice structures are commonly achieved by spatially varying the relative density and/or the topology of the lattice. However, lattice properties also heavily depend on the parent material and studies rarely investigate multi-material lattice structures, especially within metal additive manufacturing (AM) where such manufacturing methods are a novelty.

Lattice geometry (i.e. the density & topology) can be influenced and restricted by many factors during the design stage. The L-PBF method presents inherent manufacturing constraints, and many applications such as orthopaedic devices, heat exchangers, or lightweighting present additional constraints or goals for the density, pore size, surface area, etc., of the lattice. Multi-material lattices are proposed as a method to broaden the range of properties that are possible in graded lattices even with such geometry constraints.

The quality of these structures, the integrity of the material interface under loading, and how the mechanical properties of each material contribute to the overall mechanical response are yet to be studied.

This work has successfully manufactured bi-metallic lattice structures of 316L and 17-4PH stainless steel, and further metallographic analysis, computed tomography, and compression testing analyze their quality and mechanical properties.