J. Mater. Sci. Technol. ›› 2025, Vol. 215: 71-85.DOI: 10.1016/j.jmst.2024.07.024

• Research Article • Previous Articles     Next Articles

Optimizing strength-ductility in NiCoMn medium entropy alloys with atomic-scale rapid composition design

Qing Gaoa, Weibing Wanga, Junqiang Rena, Wei Lia, Biao Sangb, Le Lia, Qi Wangc, Xuefeng Lua,*, Jisen Qiaoa,*   

  1. aState Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal, Department of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
    bSchool of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, China;
    cCollege of Energy Engineering, Huanghuai University, Zhumadian 463000, China
  • Received:2024-02-16 Revised:2024-06-25 Accepted:2024-07-01 Published:2025-04-20 Online:2024-07-26
  • Contact: *E-mail addresses: lxfeng@lut.edu.cn (X. Lu), qiaojisen@lut.edu.cn (J. Qiao)

Abstract: The growing demand for material properties in challenging environments has led to a surge of interest in rapid composition design. Given the great potential composition space, the field of high/medium entropy alloys (H/MEAs) still lacks effective atomic-scale composition design and screening schemes, which hinders the accurate prediction of desired composition and properties. This study proposes a novel approach for rapidly designing the composition of materials with the aim of overcoming the trade-off between strength and ductility in metal matrix composites. The effect of chemical composition on stacking fault energy (SFE), shear modulus, and phase stability was investigated through the use of molecular dynamics (MD) and thermodynamic calculation software. The alloy's low SFE, highest shear modulus, and stable face-centered cubic (FCC) phase have been identified as three standard physical quantities for rapid screening to characterize the deformation mechanism, ultimate tensile strength, phase stability, and ductility of the alloy. The calculation results indicate that the optimal composition space is expected to fall within the ranges of 17 %-34 % Ni, 33 %-50 % Co, and 25 %-33 % Mn. The comparison of stress-strain curves for various predicted components using simulated and experimental results serves to reinforce the efficacy of the method. This indicates that the screening criteria offer a necessary design concept, deviating from traditional strategies and providing crucial guidance for the rapid development and application of MEAs.

Key words: Medium entropy alloys, Molecular dynamics, Stacking fault energy, Shear modulus, Ultimate tensile strength, Ductility