Atomic-Scale Study on the Composition Optimization and Deformation Mechanism of FeNiAl Alloys

The generalized stacking fault energy (GSFE) and shear modulus (G) are critical parameters in determining the strength and ductility balance of Fe-based alloys, playing a significant role in alloy design and performance optimization. This study focuses on FeNiAl alloys and proposes a composition optimization method based on molecular dynamics simulations. The results reveal that Fe90Ni9Al alloy exhibits the best synergy between strength and ductility, achieving a yield strength of up to 16.33 GPa and a yield strain of 10.4%. During tensile deformation, this alloy demonstrates a complex microstructural evolution, including dislocation slip, phase transformations, and deformation twinning. These mechanisms collectively contribute to the significant enhancement of its mechanical properties. This study not only elucidates the profound influence of GSFE and G on the micro-deformation mechanisms and macroscopic mechanical properties of FeNiAl alloys but also establishes an efficient composition design and screening system. This system provides theoretical support and practical guidance for the rapid development of novel alloy materials with balanced strength and ductility. The proposed method is broadly applicable to the design and optimization of high-performance structural materials, offering critical insights for advancing the application of lightweight and high-strength metallic materials in aerospace, automotive manufacturing, and other fields.