Heterogeneous Nucleation During Solidification of Undercooled Liquid Metals

小行星9308148 本研究探讨过冷液态金属合金之异质形核动力学。 动力学评价的方法有两个方向：实验测量和计算机模拟。 从锡锑合金系统的液滴样品乳化在一个稳定的载液和过冷。 在过冷过程中的成核事件，其次是量热法和定量图像分析确定的液滴尺寸分布和体积相分数。 动力学和热力学的结果有关的凝固液滴的微观结构和组成，采用扫描电子显微镜，能量色散谱，和X-射线衍射。 计算机模拟采用动力学蒙特卡罗方法和地址的临界核尺寸，形状因子，和成核在移动边界作为时间的函数。 成核是一种广泛存在的物理现象，在金属、陶瓷、有机物、生物和水体系中起着重要作用。 新的见解应该从适用于这些系统的研究中产生。 ***

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. ***