High-Throughput Investigation of Multiscale Deformation Mechanism in Additively Manufactured Ni Superalloy

In this paper, Inconel 718 (IN718) superalloy was processed by laser powder-bed fusion additive manufacturing (L-PBFAM), followed heat treatment. High-resolution nanoindentation used to investigate the complex deformation mechanisms that occurred at various length scales in both conditions. The elastoplastic maps show a strong crystal orientation dependency of modulus and hardness, which is attributed high mechanical anisotropy IN718. hardness map effectively resolves microscale strength variation imparted due hierarchical distribution associated with thermal cycles L-PBFAM. disproportionately hardening effect Nb, Mo-rich chemical segregations Laves phases dendritic structures also observed. treatment resulted 67% increase yield (from 731 MPa L-PBFAM condition 1217 heat-treated condition) activation multiple precipitation-strengthening mechanisms. mapping sample delineates orientation-dependent distribution, apart from alloy, contributed degree coherency strengthening D022 γ″-precipitates oriented parallel <001> plane γ-matrix. mean increased 13.3 GPa 14.8 after Evidence extensive twin networks dislocation cells revealed transmission electron microscopy deformed region under tip.