了解不同速率冷却的液体Ti中的结晶和无形化:一个分子动力学模拟研究.
Manash Protim Hazarika1, Puja Bordoloi1, Ajay Tripathi2
1Department of Chemistry, Sikkim University, Gangtok 737102, India.
The Journal of chemical physics
|December 18, 2024
概括
在不同的速度下冷却液态 (Ti),影响其过渡到固态. 较快的冷却促进无形化,而较慢的冷却率导致结晶进入bcc阶段.
科学领域:
- 材料科学 材料科学 材料科学
- 计算材料科学科学 计算材料科学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 结晶和无形化是受冷却速度影响的关键相位过渡.
- 了解这些过程对于从化状态产生纯金属至关重要.
- 液态 (Ti) 作为研究这些现象的模型系统.
研究的目的:
- 为了研究液体Ti中的结晶和无形化过渡.
- 分析不同冷却速率对Ti的结构和动态特性的影响.
- 验证有关冷却速度和相位转换结果之间的关系的理论预测.
主要方法:
- 使用Ti的嵌入式原子潜能进行分子动力学模拟.
- 模拟从2200K到300K的冷却过程,其速率为0.1,1和10K/s.
- 使用辐射分布函数,沃罗诺伊模块化,速度自相对应函数 (VACF),中间散射函数和动态结构因子进行分析.
主要成果:
- 化在1100-1000K之间以较慢的冷却速度 (0.1和1K/s) 结晶为体中心立方 (bcc) 阶段.
- 在相同的温度范围内,无形化以更快的冷却速率 (10K/s) 发生.
- 液体到bcc的过渡涉及到短距离,扭曲的六角密封 (hcp) /bcc类结构.
- 放松动态 (VACF,散射函数) 显示随着冷却放松度增加,较高速度更强的相关性,以及结晶/形态化过程中的明显变化.
结论:
- 冷却速度决定了液体Ti是否结晶或无形.
- 较快的冷却速度,超过液体的放松时间,导致无形化,抑制远程秩序.
- 这项研究支持了Binder关于冷却速率,放松时间和无形化的关系的理论.
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