Acta Metallurgica Sinica (English Letters) ›› 2025, Vol. 38 ›› Issue (11): 1965-1973.DOI: 10.1007/s40195-025-01904-3

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Significant Enhancement of Strength and Ductility in a Tri-Phase FeMnCoCrAl High-Entropy Alloy Through the Design of a Heterogeneous Layered Structure

Zeyu You1, Zhengyou Tang2,3(), Li Zhao2, Dongdong Cao2, Zhibing Chu1(), Hailian Gui1, Hua Ding2,3   

  1. 1School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
    2School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
    3Key Laboratory of Lightweight Structural Materials, Northeastern University, Shenyang 110819, China

Abstract:

This study optimizes the thermomechanical processing to design a heterogeneous layered structure of a tri-phase FeMnCoCrAl high-entropy alloy (HEA), achieving a significant improvement in both strength and ductility compared to the fully recrystallized structure. After annealing at 1023 K for 10 min, the microstructure of the alloy consists of a soft domain of fully recrystallized face-centered cubic (FCC) phase, a hard domain of partially recrystallized FCC phase, and a hard domain of partially recrystallized body-centered cubic phase. The tensile strength and yield strength are 604 MPa and 781 MPa, respectively, with a total elongation of 31.1%. Compared to the fully recrystallized alloy, the tensile strength is enhanced by 25%, and the total elongation increases by 23%. The comprehensive improvement in strength and ductility is attributed to multiple strengthening and toughening mechanisms within the microstructure: grain refinement strengthening from recrystallized grains, dislocation strengthening from partial recrystallization, long-range back-stress effects from the soft-hard domain structure, and deformation mechanisms such as stacking fault nucleation and the transformation-induced plasticity (TRIP)-twinning-induced plasticity (TWIP) effect, which are unique to composite the HEA.

Key words: High-entropy alloy, Heterogeneous structure, Mechanical properties