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Influence of Copper Atomic Fraction on the Mechanical Properties of FeNiCrCoCu x High⁃Entropy Alloys at High Temperature
Shenlong GAO, Mengjiao ZHAO, Tie SUN, Xiaoxiao DONG
Abstract20)   HTML1)    PDF (3409KB)(8)      

This study systematically investigates the effects of the Cu atomic fraction on the mechanical properties and microscopic deformation mechanisms of FeNiCrCoCuₓ high⁃entropy alloys at 1 000 K using molecular dynamics simulations. The results show that, as the Cu atomic fraction increases, the yield stress decreases from 5.61 GPa to 4.99 GPa and Young's modulus decreases from 70.85 GPa to 53.86 GPa. In contrast, the fraction of atoms transformed from face⁃centered cubic (FCC) to hexagonal close⁃packed (HCP) structures decreases, while the frequency of dynamic recrystallization (DRX) increases significantly. The dislocation density is reduced, lattice distortion is relaxed, and the stress distribution becomes more uniform. Further analysis confirms that Cu addition lowers the stacking⁃fault energy and accelerates DRX, thereby markedly improving ductility without compromising high⁃temperature stability. These findings provide an atomic⁃scale theoretical basis for designing novel high⁃entropy alloys with both high strength and toughness and excellent heat resistance.

2026, 46 (4): 62-68. DOI: 10.12422/j.issn.1672-6952.2026.04.008
Asynchronous Event⁃Triggered Control of Cascade Nonlinear Switched System
Tao Sun, Xiaoxiao Dong
Abstract757)   HTML    PDF (829KB)(845)      

In order to obtain good performance and required goals, the existence of asynchronous switching of controllers and subsystems must be considered. The event?triggered control of nonlinear switched system under asynchronous switching is studied. As the switching of the controller lags behind the switching of the subsystem, asynchronous behavior occurs. First, the switched nonlinear systems with linear parts and nonlinear parts are researched and the Laypunov functions are constructed. Then, a switching controller for a cascaded nonlinear switched system to obtain a closed?loop system is designed, and the average dwell time is given to get the sufficient condition for the switched system to be globally uniformly and exponentially stable. Finally, a numerical example is given to illustrate the feasibility of the method.

2021, 41 (4): 91-96. DOI: 10.3969/j.issn.1672-6952.2021.04.015