CAREER: Engineered Dendritic Microstructures

该职业奖授予内华达大学里诺分校，旨在促进对枝晶凝固的科学理解，并将这些知识应用于改进现代金属铸造方法。这项工作的主要技术目标是利用压力振荡，在凝固过程中应用于熔体，以加强对铸造过程中凝固形态的控制。在铸造过程中，将施加周期性压力脉冲，以期望的频率刺激枝晶二次臂的形成，从而确定许多重要机械性能的二次臂间距。随后，铸造样品将被表征为关键的微观结构特征（如枝晶臂间距）和机械性能（如抗拉强度）。该职业奖的教育和推广项目包括发展跨学科科学教育，创建基于计算机的学习模块，以增加讲座，并将课堂上的学生直接与PI的研究工作联系起来。此外，教育方面的努力将通过在夏季将当地高中教师引入实验室来发挥作用，最终目标是开发用于高中的新课程。在冶金学中，枝晶（树状）晶体组织是铸造组织的主要形态。枝晶组织的特征会显著影响材料的许多重要性能，如强度和延展性，这可以在一定程度上通过控制铸造工艺来控制。该奖项旨在开发新的参数，这将大大扩大对铸造显微组织和由此产生的材料性能的控制范围。将利用压力脉冲来刺激产生具有控制特性的规则间隔的枝状分支。教育计划包括发展跨学科的科学教育，创建基于计算机的学习模块，以增加讲课内容，并将课堂上的学生与研究直接联系起来。此外，当地高中教师将在夏季参加正在进行的研究活动，并鼓励他们开发新的课程，供自己的教室使用。

This Career award to University of Nevada, Reno is to advance scientific understanding of dendritic solidification, and to apply this knowledge to improve modern metal casting methods. The principal technical goal of this effort is to use pressure oscillations, applied to a melt during solidification, to enhance the control over solidification morphologies during casting. Periodic pressure pulses will be applied during the casting process to stimulate the formation of dendrite secondary arms at a desired frequency, thereby establishing the secondary arm spacing that many important mechanical properties derive from. Cast samples will subsequently be characterized for key microstructural features (such as dendrite arm spacings) and mechanical properties (such as tensile strength). Educational and outreach programs of this Career award include the development of interdisciplinary science education, and the creation of computer-based learning modules that augment lectures and connect students in the classroom directly with the PI's research efforts. Additionally, the educational efforts will be leveraged by bringing local high school teachers into the lab during the summer, with the ultimate goal of developing new curricula for use in high schools. In metallurgy, dendritic (tree-like) crystal microstructures are the predominant morphological form of the cast microstructure. The characteristics of a dendritic microstructure are known to significantly affect many important material properties such as strength and ductility, which may be controlled to an extent by controlling the casting process. This award is to develop new parameters, which will significantly expand the range of control over cast microstructures and the resulting material properties. Pressure pulses will be utilized to stimulate the creation of regularly spaced dendrite branches with controlled properties. Education plans include the development of interdisciplinary science education, and the creation of computer-based learning modules that augment lectures and connect students in the classroom directly with research. Additionally, local high school teachers, during the summer, will participate in the ongoing research activities, and are encouraged to develop new curricula for use in their own classrooms.