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Dislocation-mediated short-range order evolution during thermomechanical processing
DOI:10.1016/j.actamat.2025.121838.png)
摘要
En 中文
Thermomechanical processing alters the microstructure of metallic alloys through coupled plastic deformation and thermal exposure, with dislocation motion driving plasticity and microstructural evolution. Our previous work (Islam et al., 2025) showed that the same dislocation motion both creates and destroys chemical short-range order (SRO), driving alloys into far-from-equilibrium SRO states. However, the connection between this dislocation-mediated SRO evolution and processing parameters remains largely unexplored. Here, we perform large-scale atomistic simulations of thermomechanical processing of equiatomic TiTaVW to determine how temperature and strain rate control SRO via competing creation ( Γ) and annihilation ( λ) rates. The simulations employ systems containing 2.4 million atoms and utilize a machine learning interatomic potential optimized to capture chemical complexity through the motif-based sampling technique. Using information-theoretic metrics, we quantify that the magnitude and chemical character of SRO vary systematically with processing parameters. We identify two regimes: a low-temperature regime with weak strain-rate sensitivity, and a high-temperature regime in which reduced dislocation density and increased screw character amplify chemical bias and accelerate SRO formation. The resulting steady-state SRO is far-from-equilibrium and cannot be produced by equilibrium thermal annealing. Together, these results provide a mechanistic and predictive link between processing parameters, dislocation physics, and SRO evolution in chemically complex alloys.
期刊
IF:
9.3
论文数:
2.0W
被引数:
12.9W
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暂无机构信息
引用论文
Capturing short-range order in high-entropy alloys with machine learning potentials利用机器学习势函数捕捉高熵合金中的短程有序结构
Nanoindentation into a bcc high-entropy HfNbTaTiZr alloy-an atomistic study of the effect of short-range order
SCIENTIFIC REPORTS
IF3.9
Ab initiomolecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium 从头算 锗中液态-金属-非晶-半导体跃迁的分子动力学模拟
Exceptional enhancement of mechanical properties in high-entropy alloys via thermodynamically guided local chemical ordering通过热力学指导的局部化学有序化可异常提高高熵合金的机械性能
Extracting dislocations and non-dislocation crystal defects from atomistic simulation data从原子模拟数据中提取位错和非位错晶体缺陷

