IRES: US-Australia Collaboration on New High Strength, High Ductility Classes of High Entropy Alloys through Intermetallic Manipulation

建议摘要1559403 PI：Lori Bassman建议标题：Ires：美国和澳大利亚通过金属间操作合作开发新型高强度、高延展性的高熵合金机构：哈维·穆德学院工程应用中使用的传统合金主要由一到两种元素组成，其他元素的添加数量相对较少，以提高材料性能。然而，大量附加元素的加入通常会导致合金变得脆化。最近的工作，包括美国本科生与澳大利亚新南威尔士大学(UNSW)的研究人员和哈维·穆德学院(HMC)的Lori Bassman教授合作的工作，导致了使用新策略的新型金属合金的开发。这些先进的合金被称为高熵合金(HEA)，它们精心选择了几种元素含量大致相同的成分，并显示出优异的材料性能。该项目将极大地扩展可用于创建成功的HEA的元素组合的范围。随着拟议的新战略的实施，创造强度、延展性和成本组合更好的合金的前景将会更大。在2017年至2019年夏季的10周时间里，12名本科生将在新南威尔士大学为实现这一目标进行实验和计算研究。主要合作者，新南威尔士大学材料科学与工程学院的Kevin Laws博士和Michael Ferry教授，以及新南威尔士大学电子显微镜单元的研究人员，已经与HMC本科生合作多年。他们将继续为学生提供HMC无法提供的特定学科的专业知识和指导，以及广泛获得物理冶金实验室、显微镜设施和培训的机会。到目前为止，HEA领域的进展主要集中在确定特定的元素体系，这些元素体系可以形成一到两个简单的固溶体相，具有高热稳定性，并且没有脆性金属间化合物相。在这个项目中，将通过增加其他系统中金属间化合物相的延展性来开发新的HEA。通过这一合金开发，学生和他们的新南威尔士大学导师将细化管理HEA形成和原子有序的基本原则，并探索与HEA中显著提高的强度和延展性相关的变形机制。HMC本科生将进行的具体实验项目包括合金设计、合金制造、机械表征和微结构表征。计算项目将涉及合金结构和性能的第一性原理建模。这些经验将有助于学生成长为自信、热情的研究人员，为在国际研究环境中从事科学和工程职业做好准备。参与的学生中至少有一半是女性，并将专门招收代表人数不足的少数族裔学生。这项研究是由NSF国际科学与工程办公室的IRES项目资助的。

Abstract for proposal 1559403 PI: Lori BassmanProposal Title: IRES: US-Australia collaboration on new high strength, high ductility classes of high entropy alloys through intermetallic manipulationInstitution: Harvey Mudd CollegeTraditional alloys used in engineering applications consist primarily of one or two elements, with other elements added in relatively small quantities to enhance material properties. However, the inclusion of large quantities of additional elements typically causes alloys to become brittle. Recent work, including that by American undergraduate students working with researchers at the University of New South Wales (UNSW) in Australia and Prof. Lori Bassman of Harvey Mudd College (HMC), has led to the development of novel metal alloys using a new strategy. These advanced alloys, called high entropy alloys (HEAs), have carefully selected compositions with approximately equal amounts of several elements and have demonstrated excellent material properties. This project will greatly expand the range of combinations of elements that can be used to create successful HEAs. With the proposed new strategy will come increased promise for creating alloys with improved combinations of strength, ductility and cost. During ten week periods in the summers of 2017 to 2019, twelve undergraduate students will conduct experimental and computational research at UNSW towards this goal. The lead collaborators, Dr. Kevin Laws and Prof. Michael Ferry in the UNSW School of Materials Science and Engineering, and researchers in the UNSW Electron Microscope Unit have worked with HMC undergraduates for many years. They will continue to provide students with discipline-specific expertise and mentoring unavailable at HMC as well as extensive access to physical metallurgy laboratories, microscope facilities and training.Progress in the HEA field so far has focused on identification of specific systems of elements that can form one or two simple solid solution phases with high thermal stability and no brittle intermetallic phases. In this project new HEAs will be developed by increasing the ductility of intermetallic phases that occur in other systems. Through this alloy development, the students and their UNSW mentors will refine the fundamental principles that govern HEA formation and atomic ordering and explore the deformation mechanisms associated with greatly enhanced strength and ductility in HEAs over conventional alloys. The specific experimental projects to be performed by HMC undergraduates include alloy design, alloy fabrication, mechanical characterization and microstructural characterization. Computational projects will involve first-principles modeling of alloy structures and properties. These experiences will contribute to the maturation of the students into confident, enthusiastic researchers who are prepared for science and engineering careers in international research environments. At least half of the participating students will be female, and underrepresented minority students will be specifically recruited. This research is funded by the IRES program of the NSF Office of International Science and Engineering.