CAREER: Role of Ternary Alloying Elements in Eutectic Solidification

摘要从基础科学和应用的角度来看，多组分金属合金凝固过程中微观组织的形成过程都引起了人们极大的兴趣。一种特殊的材料被称为共晶材料，包括从铸铁到无铅焊料再到自组装复合材料的所有材料。新的实验数据对于建立能够准确预测这些复杂材料的行为的理论和模型是必要的，从而使它们能够在高级应用中使用。各种精心控制的实验条件将用于研究选定的三组分共晶系统的行为。最先进和新颖的凝固技术将用于研究加工参数，结构细节和材料性能之间的关系。这项工作还包括为材料科学与工程领域的研究生、本科生和高中生的招聘和专业发展制定一个全面的计划。这项工作包括为地区高中生组织一个材料夏令营项目。PI将与UAB的社区外展发展中心（CORD）合作，扩大申请人群体的多样性，并改进项目的课程和评估工具，这些工具将与全国各地的其他材料营地共享。最后，PI将利用她的国际经验，通过在校园和国外教授的重新开发的历史课程，培养STEM本科生的全球能力。作为多组分、多相材料的一部分，共晶结构具有重要的基础和应用价值。虽然具有非面界面的二元共晶已经被很好地理解，但描述更复杂的共晶（具有三个或更多相和/或具有面界面的共晶）的结构和行为的理论还没有很好地发展。这些复杂的共晶近年来因其作为原位复合材料和自组装超材料的潜力而重新受到关注，但要实现这些先进的应用，需要更好地控制微观结构的发展。各种精心控制的实验条件将用于研究选定的三元共晶系统的行为，包括规则和不规则。最先进的定向凝固技术，以及一种新的等轴凝固方法，将用于研究各向异性、晶体失配、非平衡模式形成、相间边界对准、主导取向关系和晶体织构演变之间的关系。此外，还将通过原位观察和后处理观察来阐明三元元素对共晶间距和界面稳定性的影响。该提案包括一个全面的计划，为材料科学和工程领域的研究生，本科生和高中生的招聘和专业发展，建立在PI在这些领域的既定记录之上。来自UAB多元化学生群体的研究生和本科生研究人员将进行研究，培养实验、分析和沟通技能，为他们未来在工业界和学术界的职业生涯做好准备。这些学生将协助PI组织和运行一个面向地区高中生的暑期材料夏令营项目。PI将与UAB的社区外展发展中心（CORD）合作，扩大申请人群体的多样性，并改进项目的课程和评估工具，这将与全国其他ASM材料营共享。最后，PI将利用她的国际经验，通过重新开发校园内外的历史课程，培养STEM本科生的全球能力。

Non-Technical AbstractThe process of microstructure formation during solidification in multi-component metal alloys is of great interest from both a fundamental scientific and an applied point of view. One particular class of materials, called eutectics, includes everything from cast iron to lead-free solder to self-assembling composites. New experimental data is necessary to develop theories and models that can accurately predict the behavior of these complicated materials, enabling their use in advanced applications. A variety of carefully controlled experimental conditions will be used to investigate the behavior of selected three-component eutectic systems. State-of-the-art and novel techniques for solidification will be used to investigate the relationships between processing parameters, structural details and material properties. The work also includes a well-rounded program for the recruitment and professional development of graduate, undergraduate, and high school students in the field of materials science and engineering. This work includes the organization of a Materials Camp program for area high school students. The PI will work with UAB's Center for Community OutReach Development (CORD) to expand the diversity of the applicant pool as well as to improve curriculum and assessment tools for the program, which will be shared with other Materials Camps across the country. Finally, the PI will use her international experience to develop global competency in undergraduate STEM students through redeveloped history courses taught both on campus and abroad.Technical AbstractAs part of the larger class of multi-component, multi-phase materials, eutectics structures are of both fundamental and applied interest. While binary eutectics with non-faceted interfaces are relatively well understood, theories describing the structure and behavior of more complicated eutectics - those with three or more phases and/or with faceted interfaces - are not well developed. These complex eutectics have received renewed interest in recent years for their potential as in-situ composites and self-assembling metamaterials, but better control of microstructure development is needed to realize these advanced applications. A variety of carefully controlled experimental conditions will be used to investigate the behavior of selected ternary eutectic systems, both regular and irregular. State-of-the-art techniques for directional solidification, along with a novel method of equiaxed solidification, will be used to investigate the relationships between anisotropy, crystal mismatch, non-equilibrium pattern formation, alignment of interphase boundaries, prevailing orientation relationships, and the evolution of crystallographic texture. In addition, the role of ternary elements on eutectic spacing and interface stability will be elucidated through in situ and post processing observation.This proposal includes a well-rounded program for the recruitment and professional development of graduate, undergraduate, and high school students in the field of materials science and engineering, building on the PI's established track record in these areas. Graduate and undergraduate student researchers from UAB's diverse student body will carry out the research, developing experimental, analytical, and communication skills that will prepare them for future careers in industry and academia. These students will assist the PI in organizing and running a summer Materials Camp program for area high school students. The PI will work with UAB's Center for Community OutReach Development (CORD) to expand the diversity of the applicant pool as well as to improve curriculum and assessment tools for the program, which will be shared with other ASM Materials Camps across the country. Finally, the PI will use her international experience to develop global competency of undergraduate STEM students through redeveloped history courses taught on and off campus.