摘要
The grain boundary character distribution of an equiatomic CoCrFeMnNi high-entropy alloy (HEA) was statistically determined using electron backscatter diffraction. The face-centered cubic (fcc) HEA exhibits an exceptionally high fraction of the Σ3 coherent twin boundary, constituting 94% of the total Σ3 grain boundary (GB) population, which is nearly double the levels observed in Cu (51%) and Ni (61%). This reflects an increased thermodynamic preference for the lowest-energy state, driven by suppressed GB energy anisotropy and a deeper relative energy minimum at the coherent twin configuration compared to fcc elemental metals (Au, Cu, and Ni). Beyond Σ3 misorientation, high-entropy effects from configurational entropy and local lattice distortion further stabilize {111} symmetrical twist configurations, leading to significant population enrichment across multiple misorientations, including Σ7, Σ13b, and Σ21a. Ultimately, these findings reinforce the high-entropy grain boundaries (HEGBs) framework, providing a foundation for next-generation multifunctional high-entropy materials. © 2026 Acta Materialia Inc.