Design Guidelines for High Strength Multicomponent Alloys

一种新的被称为“高熵合金”的合金正在成为高强度应用的候选材料。这些合金具有非常复杂的化学成分，并且由大量元素组成。它们变形的过程也很复杂。该奖项支持了解这些合金的变形和断裂行为的研究。研究人员试图了解如何利用这些材料的复杂成分来促进高强度和延展性合金的研究。通过改变不同的成分和加工参数，预计可以找到有用的标准来优化强度和塑性的组合。这项研究将被纳入课程开发，以供未来几代研究人员接受培训，以便结合实验使用这些计算工具。该项目通过在本科和研究生课程、夏令营和实习中使用的网络教育模块，促进高中生和本科生的教育。这些教材是专门为女学生编写的，以鼓励她们参与这一领域。这项研究工作是基于这样一个假设，即通过改变原子相互作用参数，可以找到有用的准则来优化强度和延性的组合。由于第一性原理计算可以研究的原子数量有限，研究人员将利用简单的模型相互作用势来研究原子大小、结合能和化学相互作用的不同程度的变化。他们将获得强度和断裂韧性的趋势，作为这些不同程度的复杂程度的函数。这些趋势将与现有的各种高熵合金力学行为的实验研究进行比较，这些实验研究表明，在保持高强度的同时提高了延展性。这里为模型交互开发的方法为未来的计算建模提供了基础。最重要的是，这项工作提供的洞察力使单相高熵合金的设计更加有效，适用于各种应用。

A new class of alloys called "High Entropy Alloys" is emerging as candidate materials for high strength applications. These alloys have very complex chemistries and are composed of a large number of elements. The processes by which they deform are also complex. This award supports research to understand deformation and fracture behavior of these alloys. The researchers seek to understand how the complex composition of these materials can be used to advantage the search of high strength and ductile alloys. By varying different compositional and processing parameters, it is expected that useful criteria may be found to optimize the combination of strength and ductility. The research will be incorporated in curriculum development for the education of future generations of researchers that are trained to use these computational tools in combination with experiments. The project contributes to the education of high school and undergraduate students through web educational modules used in undergraduate and graduate courses, summer camps, and internships. These instructional materials are geared particularly for female students to encourage their participation in this field. This research effort is based on the hypothesis that by varying atomic interaction parameters, useful criteria can be found to optimize the combination of strength and ductility. Because of limitations in the number of atoms that can be studied using first principle calculations, the researchers will utilize simple model interaction potentials for various degrees of variation in atomic sizes, cohesive energies, and chemical interaction. They will obtain trends in strength and fracture toughness as a function of these varying degrees of complexity. These trends will be compared with available experimental studies of the mechanical behavior of various high entropy alloys that indicate increased ductility while maintaining high strength. The methodology developed here for model interactions provides a basis for future computational modeling. Most importantly, the insight provided by this work enable more efficient design of single-phase high entropy alloys for a variety of applications.