Additively Manufacturing of Eutectic Multicomponent Alloys with Nanolamellar FCC and B2 Phases

Laser-based directed energy deposition (DED) technique provides new opportunities for fabricating eutectic eutectic multicomponent alloys or high entropy alloys (EHEAs) with directional nanolamellar structures that exhibit superior mechanical properties. The mechanisms of co-deformation, strengthening, fracture of the two constituent phases, and their resulting anisotropic mechanical properties, have not yet been systematically studied. Here we employ <i>in situ</i> synchrotron-based high-energy X-ray diffraction and X-ray tomography to study a DED-fabricated nanolamellar AlCoCrFeNi_2.1 that is comprised of face-centered cubic (fcc) and ordered body-centered cubic (B2) phases. This study demonstrates that the DED-produced EHEAs exhibit the optimal strength-ductility synergy along the lamellar direction and provides a fundamental understanding of the co-deformation behavior of dual phases in directional nanolamellar structures.