In situ interlayer hot forging arc-based directed energy deposition of Inconel® 625: process development and microstructure effects

The typical as-built coarse and cube-oriented microstructure of Inconel® 625 parts fabricated via arc-based directed energy deposition (DED) induces anisotropic mechanical behavior, reducing the potential applications DEDed in critical components. In this sense, present work aimed to reduce grain size texture by applying an situ interlayer hot forging (HF) combined with post-deposition heat treatments (PDHT). produced samples were characterized through optical microscopy, scanning electron microscopy coupled backscatter diffraction, synchrotron X-ray Vickers microhardness. Also, a dedicated deformation tool was designed optimized finite element method model considering processing conditions thermal cycle experienced material. It is shown that induced thermo-mechanical-affected zone (dynamic recrystallized + remaining deformation, height ≈ 1.2 mm) at bead top surface, which resulted thinner aligned grains lower index relation DED counterpart. addition, effects solution (1100 °C/ 1 h) stabilization (980 PDHTs on HF-DEDed also analyzed, promoted fine equiaxed static without cube orientation, comparable wrought Therefore, HF-DED process significantly refined highly oriented Ni-based superalloys obtained DED.