The rapid solidification of an AL-10wt%Si-Sc alloy

合金凝固是与铸造和表面加工有关的许多现代实验技术和工业技术中出现的复杂现象。不同凝固条件（如过冷或冷却速度）的变化使控制晶体结构的形态和尺寸成为可能，这实质上影响合金的物理和化学性能。特别是，合金的深度过冷低于平衡液相线和共晶导致快速凝固，并产生具有改进的机械，磁性和电学性能的材料。这个为期3年的项目是Equispheres和阿尔伯塔大学的合作项目。我们将使用脉冲雾化（IA）——一种单流体快速凝固技术来生成粉末样品。Al-Si （Sc）合金将生成。由于过冷，后者预计会在α矩阵中过饱和。用扫描电镜、x射线衍射、差示扫描量热法和显微硬度对固化后的样品进行表征。此外，最先进的表征，如3d微和纳米层析成像和中子衍射将进行。快速凝固液滴的内部枝晶结构将使用微偏析模型来模拟。收集的特征数据将用于验证模型。我们将为理解凝固过程产生的凝固结构提供基础，例如3d打印和高压压铸，其中冷却速率和热通量与IA相似。拟议的合金系统对汽车和航空航天应用非常重要，加拿大**在这些领域的生产和制造中发挥着重要作用。一名研究生将在加拿大接受培训

Solidification of alloys is a complex phenomenon arising in many modern experimental techniques and industrial technologies related to casting and surfaces processing. The variation of different conditions of solidification (such as undercooling or cooling rate) gives a possibility to control the morphology and size of crystal structure, which substantially influence physical and chemical properties of alloys. In particular, deep undercooling of alloys below equilibrium liquidus, and eutectics results in rapid solidification and yields materials with improved mechanical, magnetic and electrical properties. The proposed 3 year project is a collaboration between Equispheres and the Univ. of Alberta. We will generate powder samples using Impulse Atomization (IA) - a single fluid rapid solidification technique. Al-Si (Sc) alloys will be generated. The latter is expected to be supersaturated in the alpha matrix due to undercooling. The solidified samples will be **characterized using SEM, X-Ray diffraction, differential scanning calorimetry and microhardness. In addition, state of the art characterization such as 3D-micro and nano-tomography and Neutron Diffraction will be carried out. The internal dendritic structure of a rapidly solidified droplet will be modeled using a microsegregation model. The characterization data collected will be used to verify the model. We will provide a basis for understanding the solidification structure resulting from solidification processes such as3D printing and high pressure die casting where cooling rates and heat fluxes are similar to IA. The proposed alloy systems are important for automotive and aerospace applications where Canada **plays a major role in production and manufacturing. One graduate student will be trained in Canada.**