Process-intrinsic cellular network for sustained strength-ductility across temperatures in a 3D-printed multi-principal-element alloy

Laser-based additive manufacturing (LAM) provides a transformative route for fabricating Cr-Fe-Co-Ni-Al-Ti-based multi-principal element alloys (MPEAs). These alloys typically rely on L1₂ precipitate strengthening and thus require post-processing; however, such treatments rarely ensure stable mechanical performance over a wide temperature range. Here we designed a (CrFeCo)₄₈Ni₃₄Al₇Ti₅V₅Ta₁ MPEA with a self-assembled body-centred cubic/L2₁ precipitate cellular network formed intrinsically during LAM. Slip transfer and back-stress hardening across Kurdjumov-Sachs and Nishiyama-Wassermann interfaces and a weakly temperature-dependent stacking fault energy stabilize the dislocation-mediated deformation from 77 to 873 K. Consequently, the MPEA maintains a yield strength above 1 GPa and a uniform elongation of approximately 20% over a wide temperature range, indicating relatively stable tensile performance. This process-intrinsic pathway circumvents the need for post-treatment and reveals interface-mediated plasticity mechanisms. Our findings demonstrate that interface coherency engineering provides a foundation for designing strong yet ductile alloys with reduced temperature sensitivity via LAM.