Heterogeneous Nucleation During Solidification of Undercooled Liquid Metals

过冷液态金属凝固过程中的异质成核

• 批准号: 9308148
• 负责人: John Perepezko
• 金额: $ 33.67万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-01 至 1997-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9308148&HistoricalAwards=false
• 关键词: Heterogeneous; Nucleation; During; Solidification; Undercooled

9308148 Perepezko This research explores kinetics of heterogeneous nucleation in undercooled liquid metal alloys. The approach to the kinetics evaluation follows two directions: experimental measurement and computer simulation. Droplet samples from the tin-antimony alloy system are emulsified in a stable carrier fluid and undercooled. Nucleation events during undercooling are followed by calorimetry and the droplet size distribution and volume phase fraction determined by quantitative image analysis. Kinetic and thermodynamic results are related to the microstructure and composition of the solidified droplets by employing scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. Computer simulation employs the Kinetic Monte Carlo method and addresses critical nucleus size, shape factors, and nucleation at moving boundaries as a function of time. %%% Nucleation is a physical phenomena of broad occurrence, playing an important role in metallic, ceramic, organic, biological, and aqueous systems. New insights should result from this research applicable to these systems. ***

9308148 Perepezko这项研究探讨了底冷液体金属合金中异质成核的动力学。 动力学评估的方法遵循两个方向：实验测量和计算机模拟。 锡抗抗合金系统中的液滴样品在稳定的载体流体中被乳化并过冷。 在过冷时的成核事件之后是量热法，液滴尺寸分布和通过定量图像分析确定的体积相位分数。 动力学和热力学结果与使用扫描电子显微镜，能量色散光谱和X射线衍射有关凝固液滴的显微结构和组成。 计算机模拟采用动力学蒙特卡洛方法，并解决了随时间的函数，在移动边界时解决了关键的核大小，形状因子和成核。 %% %%成核是一种广泛发生的物理现象，在金属，陶瓷，有机，生物学和水性系统中起着重要作用。 这项研究适用于这些系统的新见解应产生。 ***