Hybrid additive manufacturing of CuCrZr/IN625 multi-material structure via laser-powder bed fusion and laser-directed energy deposition

Herein, we fabricate a CuCrZr/IN625 multi-material structure via L-DED of Inconel 625 (IN625) onto L-PBF-processed CuCrZr block surface. The CuCrZr/IN625 interface exhibits a hierarchical heterogeneous structure, characterized by highly spherical Ni-rich grains embedded in the Cu-rich matrix and decorated by nanoscale Laves, ZrO₂, and Cr₇C₃ precipitates.

Numerical simulations reveal that this structure arises from Marangoni convection-driven liquid transport and non-equilibrium solidification. The interfacial region exhibits an ultrahigh tensile yield strength of 1071±17 MPa through synergistic precipitation, grain-boundary, and hetero-deformation-induced strengthening, and delivers a shear strength ~98 MPa higher than that of pure CuCrZr. This work elucidates the formation and strengthening mechanisms of the CuCrZr/IN625 interface, guiding the design of high-performance multi-material components for aerospace applications.