The current study investigates laser–directed energy deposition (L-DED) of bimetallic SS316/IN718 structures fabricated with graded volumetric fractions of SS316L and IN718 with an interface oriented either parallel (XY) or perpendicular (Z) to the loading axis. Specimens included monolithic SS316L and IN718 alongside with three different bimetallic configurations. For both XY and Z orientations, a series of mechanical and microstructural characterization analysis were applied that included; uniaxial quasi-static tensile tests, full field localized strain assessment using DIC, Vickers microhardness, SEM, EDS and Optical microscopy for the fracture surface. Anisotropy was quantified using a vectorial Euclidean-distance framework for the first time across four mechanical properties simultaneously, identifying the SSIN-30/70 condition as the most anisotropic, while monolithic SS316 exhibited the lowest anisotropy. Comparison with prior work demonstrated similar strain-hardening capacity and strength–ductility synergy, while underscoring elevated hardness in the present builds. Collectively, these results establish a clear linkage between build orientation, interface direction, and tensile performance in additively manufactured nickel-base/austenitic-steel systems, reaffirming process-driven anisotropy as a central challenge and motivating microstructure-aware processing and post-processing strategies for load-critical applications.
Sayed et al. (Fri,) studied this question.