CAREER: Engineered Dendritic Microstructures

这项授予雷诺内华达大学的职业生涯奖是为了促进对树枝晶凝固的科学理解，并应用这些知识来改进现代金属铸造方法。这项工作的主要技术目标是使用压力振荡，在凝固过程中对熔体施加，以加强对铸造过程中凝固形态的控制。在铸造过程中，将施加周期性的压力脉冲，以刺激以所需频率形成的树枝晶二次臂的形成，从而建立许多重要机械性能所依据的二次臂间距。随后将对铸造样品的关键组织特征(如枝晶臂间距)和机械性能(如抗拉强度)进行表征。这一职业奖项的教育和推广计划包括发展跨学科的科学教育，以及创建基于计算机的学习模块，以增加授课内容，并将课堂上的学生直接与PI的研究工作联系起来。此外，教育努力将通过在暑期将当地高中教师引入实验室来发挥杠杆作用，最终目标是开发供高中使用的新课程。在冶金中，树枝状(树枝状)晶体组织是铸态组织的主要形态。众所周知，树枝晶组织的特征对许多重要的材料性能有重要影响，如强度和塑性，这可以通过控制铸造工艺在一定程度上进行控制。这一奖项是为了开发新的参数，这将显著扩大对铸造组织和由此产生的材料性能的控制范围。压力脉冲将被用来刺激具有受控特性的规则间隔的树枝的产生。教育计划包括发展跨学科的科学教育，以及创建基于计算机的学习模块，以加强授课内容并将课堂上的学生与研究直接联系起来。此外，在暑假期间，当地高中教师将参加正在进行的研究活动，并鼓励他们制定新的课程，以便在自己的课堂上使用。

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.