CAREER: Role of Ternary Alloying Elements in Eutectic Solidification

从基础科学和应用的角度来看，多元金属合金凝固过程中微观组织的形成过程是一个非常重要的问题。一类特殊的材料被称为共晶，从铸铁到无铅焊料再到自组装复合材料，应有尽有。新的实验数据对于开发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。将使用各种精心控制的实验条件来研究选定的三组分共晶系统的行为。将使用最先进和新颖的凝固技术来研究工艺参数、结构细节和材料性能之间的关系。这项工作还包括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的全面计划。这项工作包括为地区高中生组织材料夏令营计划。PI将与UAB的社区拓展发展中心(CORD)合作，扩大申请者群体的多样性，并改进该计划的课程和评估工具，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，通过重新开发在校园和国外教授的历史课程，培养STEM本科生的全球能力。技术摘要作为更大的多组分、多相材料类别的一部分，共晶结构具有基础和应用两方面的兴趣。虽然具有非刻面界面的二元共晶相对较好地被理解，但描述更复杂的共晶的结构和行为的理论--那些具有三个或更多相和/或具有刻面界面的那些--并没有很好地发展。近年来，这些复杂的共晶材料因其作为原位复合材料和自组装超材料的潜力而重新引起人们的兴趣，但要实现这些高级应用，还需要更好地控制微观结构的发展。将使用各种精心控制的实验条件来研究选定的三元共晶系统的行为，包括规则和不规则的。最先进的定向凝固技术和一种新的等轴凝固方法将被用来研究各向异性、晶体失配、非平衡图案形成、相界排列、主要取向关系和晶体织构演变之间的关系。此外，三元元素对共晶间距和界面稳定性的作用将通过现场和后处理观察来阐明。这项建议包括一个全面的计划，以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为基础，建立在PI在这些领域的既定记录的基础上。来自UAB不同学生群体的研究生和本科生研究人员将开展研究，培养实验、分析和沟通技能，为他们未来在工业和学术界的职业生涯做好准备。这些学生将协助PI为地区高中生组织和运行夏季材料夏令营计划。PI将与UAB的社区拓展发展中心(CORD)合作，扩大申请者群体的多样性，并改进该计划的课程和评估工具，这些工具将与全国各地的ASM材料训练营共享。最后，PI将利用她的国际经验，通过重新开发校内外教授的历史课程，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.