Metallic glass induces columnar-to-equiaxed transition for synergistic microstructure-property trade-off in additively manufactured Al0.1CoCrFeNi high-entropy alloys

The inherently low room-temperature strength of face-centered cubic high-entropy alloys (FCC-HEAs) severely limits their widespread application. Here, we report a strategy to overcome this limitation by reinforcing Al 0.1 CoCrFeNi HEA with Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 (Vit1) metallic glass (MG) using laser powder bed fusion (LPBF). A series of X wt% HEA/ X MG ( X = 0, 2, 5, 7, 10) high-entropy alloy composites (HEACs) were successfully fabricated, and the influence of Vit1 addition on their microstructure and mechanical properties was systematically investigated. The results show that the introduction of Vit1 effectively suppresses the epitaxial growth of columnar grains and promotes a columnar-to-equiaxed transition (CET), refining the average grain size significantly from 11.9 μm to 3.0 μm. This transition is associated with Vit1 crystallization, solute redistribution, and the intrinsic rapid solidification conditions during LPBF. Moreover, nanoscale precipitates formed at the CET interface are identified as Ni 3 Zr and Ni 7 Zr 2 , which exhibit a non‑coherent relationship with the Al 0.1 CoCrFeNi matrix. Among the investigated HEACs, the HEA/5MG sample exhibits the highest ultimate tensile strength of 1004 MPa, with a tensile elongation of 4.35%. This superior ultimate tensile strength arises from the synergistic contributions of precipitation strengthening, grain-boundary strengthening, and dislocation strengthening. The present work provides a new pathway for designing high-performance HEACs via interface engineering in additive manufacturing.