在分子动力学模拟中,在拉伸变形下Fe-C合金中微裂变的机制
Yanan Zeng1, Xiangkan Miao1, Yajun Wang1
1School of Metallurgy and Energy Engineering, North China University of Science and Technology, Tangshan 063210, China.
Materials (Basel, Switzerland)
|August 28, 2025
概括
分子动力学模拟显示,温度上升会降低Fe-C合金的强度并改变其变形机制. 较高的温度加快空气增长和相位过渡,导致更快的材料失效.
科学领域:
- 材料科学
- 计算材料科学
- 固体机械学
背景情况:
- 了解压力下的材料行为对于工程应用至关重要.
- 微裂变的开始和演变对材料的性能和故障有重大影响.
- 热条件对机械性能和变形机制起着至关重要的作用.
研究的目的:
- 在单轴拉伸负荷下研究Fe-C合金的微裂变和演变.
- 阐明受不同热条件影响的微观变形机制.
- 分析温度对Fe-C合金机械反应和结构变化的影响.
主要方法:
- 用于模拟Fe-C合金的分子动力学 (MD) 模拟.
- 在单轴拉伸负荷下沿 z 轴进行模拟.
- 温度在300K到1100K之间,变压率为2×10^9s^1.
主要成果:
- 随着温度的提高,Fe-C合金的承强度和峰值应力都会下降.
- 双峰应力-应变曲线 (300-700K) 表示应力诱导的转变和空隙核化/增长.
- 单峰曲线 (900-1100 K) 显示加速的空隙凝聚和快速的应力下降.
- 观察到的阶段过渡包括BCC到FCC和-HCP,随后是回归到BCC和未识别的结构.
- 高温会增加原子的移动性,破坏结构,并通过空气增长加速失效.
结论:
- 温度显著影响Fe-C合金的变形机制和故障模式.
- 微观结构的演变,包括相位过渡和空气动力学,是温度依赖的.
- 较高的温度通过空气增长促进更快的能量消散,导致过早的材料故障.
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