Scholarlink

<p>Molecular dynamics simulations (MD), guided by CALPHAD pseudo-binary phase diagrams and validated experimentally, were employed to investigate the microstructure and tensile behavior of Al<sub>0.6+x</sub>CoCrFeNi<sub>2.5−x</sub>Si<sub>0.1</sub> high-entropy alloys (HEAs) with <i>x</i> = 0, 0.2, and 0.4. The phase diagram shows a clear transition from B2-dominated hypoeutectic to FCC-dominated hypereutectic structures as the Al/Ni ratio decreases. The eutectic composition AlCoCrFeNi<sub>2.1</sub>Si<sub>0.1</sub> exhibits the best strength–ductility balance in both simulation and experiment. This superiority arises from maximal lattice distortion, a fine lamellar FCC + B2 dual-phase microstructure, and synergistic operation of multiple deformation mechanisms, including extensive Shockley partial dislocation activity, deformation twinning, and stress-induced FCC-to-HCP and FCC-to-BCC transformations. Higher Al content enhances solid solution strengthening and lattice distortion, thereby increasing strength at the expense of ductility. Polycrystalline models reveal continuous yielding dominated by grain-boundary-mediated dislocation nucleation, absorption, and phase transformation. Grain refinement to approximately 6.6&#xa0;nm obeys the classical Hall–Petch relationship. These findings elucidate the atomic-scale origins of the strength–ductility trade-off and offer rational design principles for high-performance eutectic HEAs.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Molecular Dynamics Simulation of the Microstructure and Mechanical Properties of Al0.6+xCoCrFeNi2.5−xSi0.1 High-Entropy Alloys

  • 期刊论文

  • 发表日期：

    2026年5月26日

查看全文
  • Fa Chang,
  • Yuechun Ni,
  • Yu Zhu,
  • Chunxia Wei,
  • Jin Shi,
  • Jianeng Huang,
  • Pin-Qiang Dai,
  • Qunhua Tang

摘要

Molecular dynamics simulations (MD), guided by CALPHAD pseudo-binary phase diagrams and validated experimentally, were employed to investigate the microstructure and tensile behavior of Al0.6+xCoCrFeNi2.5−xSi0.1 high-entropy alloys (HEAs) with x = 0, 0.2, and 0.4. The phase diagram shows a clear transition from B2-dominated hypoeutectic to FCC-dominated hypereutectic structures as the Al/Ni ratio decreases. The eutectic composition AlCoCrFeNi2.1Si0.1 exhibits the best strength–ductility balance in both simulation and experiment. This superiority arises from maximal lattice distortion, a fine lamellar FCC + B2 dual-phase microstructure, and synergistic operation of multiple deformation mechanisms, including extensive Shockley partial dislocation activity, deformation twinning, and stress-induced FCC-to-HCP and FCC-to-BCC transformations. Higher Al content enhances solid solution strengthening and lattice distortion, thereby increasing strength at the expense of ductility. Polycrystalline models reveal continuous yielding dominated by grain-boundary-mediated dislocation nucleation, absorption, and phase transformation. Grain refinement to approximately 6.6 nm obeys the classical Hall–Petch relationship. These findings elucidate the atomic-scale origins of the strength–ductility trade-off and offer rational design principles for high-performance eutectic HEAs.