Novel functionally-graded material design of additive manufactured Corrax maraging stainless steel lattice

[Display omitted] •The effects of a novel functionally-graded material on the compressive performances of LPBF Corrax maraging stainless steel lattices were investigated.•The FGM-V lattice exhibited higher SEA than the FCCZ and cubic lattices due to the effective alleviation of strain localization.•The specific energy absorptions of LPBF Corrax lattices were comparable to those of LPBF Ti-based lattices in the literature. The effects of a functionally-graded material (FGM) designed with two types of unit cells, cubic and face-centered cubic with Z-axis struts (FCCZ), on the compressive performances and fracture mechanisms of powder bed fusion-laser beam\metals (PBF-LB\M) Corrax maraging stainless steel lattices were investigated. FGM lattices with gradient directions parallel and vertical to the compressive loading were respectively designated as FGM-P and FGM-V lattices. The results showed that the FCCZ lattice exhibited higher compressive properties than the cubic lattice did. The fracture modes of FCCZ and cubic lattices were respectively ∼45° shear fracture and layer-by-layer fracture. The FGM-V lattice exhibited higher specific energy absorption at 50 % strain than the FCCZ and cubic lattices did by 7.6 % and 19.4 %, respectively. This phenomenon can be attributed to the effective alleviation of strain localization in the FGM-V lattice postponing the fracture. Furthermore, the specific energy absorptions of PBF-LB\M Corrax lattices were comparable to those of PBF-LB\M Ti-based alloy lattices in the literature. Thus, the PBF-LB\M Corrax lattice appears to be a potential low-cost material for high-performance and lightweight structural applications. This lattice design extends the flexibility of additive manufactured lattices and provides a specific guideline for further improving their mechanical performances.