CAREER: Fundamental investigation of twin boundary engineering through cyclic cross-phase-boundary thermomechanical processing

非技术性总结该学院早期职业发展（CAREER）奖支持研究和教育活动，以开发材料加工策略，以制造更坚固和/或更具延展性的钛（Ti）合金。钛合金的机械性能受到材料中存在的缺陷和其他精细结构的显著影响，这对预测或设计具有挑战性。在这个项目中，首席研究员和她的团队将开发不同长度尺度的模型，以计算预测钛合金在热载荷和机械载荷下精细结构的演变。该研究将导致在钛合金中合理生产精细结构的策略，从而获得所需的机械性能，这将有利于航空航天，汽车和其他对钛合金需求不断增加的行业。该项目将紧密结合研究和教育活动，包括科学展览，课程开发，研究指导，在线教育和研究工具共享，以“强韧性金属合金”为主题，培养K-12，本科和研究生层次的多元化学生，培养具有材料和力学综合知识的科学人才。该项目将使开发的教育模块和研究工具可供在线和面对面的参与者使用。技术总结该职业奖支持旨在建立基于物理的热机械加工途径以合理地在钛合金中创建所需微观结构的研究和教育活动。钛合金的力学性能直接取决于其微观结构，包括孪晶界、位错、相界和晶界。因此，迫切需要开发有效的热机械加工策略来控制钛合金的微观结构。为了实现这一目标，PI和她的团队将致力于三个研究方向，重点是（i）使用原子模拟和第一性原理计算阐明钛合金中的微观结构形成机制;（ii）通过相场有限元建模将微观结构演化的原子机制提升到宏观力学;以及（iii）开发跨相界热机械路径以控制Ti合金中的微结构的形成。该项目将促进对钛合金微观结构演变的基本理解和建模，加速钛合金热机械加工方法和合金成分的发展。该项目将紧密结合研究和教育活动，包括科学展览，课程开发，研究指导，在线教育和研究工具共享，以“强韧性金属合金”为主题，培养K-12，本科和研究生层次的多元化学生，培养具有材料和力学综合知识的科学人才。该项目将使开发的教育模块和研究工具可供在线和亲自参与者使用。（通过凝聚态物质和材料理论和金属和金属纳米结构计划）和土木，机械，和制造业创新（通过材料与结构力学计划）该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis Faculty Early Career Development (CAREER) award supports research and education activities to develop material processing strategies to manufacture stronger and/or more ductile titanium (Ti) alloys. The mechanical properties of Ti alloys are significantly affected by the defects and other fine structures present in the material, which are challenging to predict or design. In this project, the principal investigator and her team will develop models at different length scales to computationally predict the evolution of fine structures in Ti alloys under thermal and mechanical loadings. The research will lead to strategies to rationally produce fine structures in Ti alloys, thus obtaining desired mechanical properties, which will benefit aerospace, automotive, and other industries that have an increasing demand of Ti alloys. This project will tightly integrate research and educational activities, including science exhibits, curriculum development, research mentoring, online education, and research tool sharing, with an overarching theme of “strong and ductile metal alloys” to train a diverse body of students at the K-12, undergraduate, and graduate levels toward fostering a scientific workforce with integrated knowledge of materials and mechanics. The project will make the developed education modules and research tools accessible to both online and in-person participants.TECHNICAL SUMMARYThis CAREER award supports research and education activities aimed at establishing physics-based thermomechanical processing pathways to rationally create desired microstructures in Ti alloys. Mechanical properties of Ti alloys are directly determined by their microstructures, including twin boundaries, dislocations, phase boundaries, and grain boundaries. It is, therefore, imperative to develop effective thermomechanical processing strategies to control microstructures in Ti alloys. To achieve this goal, the PI and her team will pursue three research thrusts that focus on (i) elucidating microstructure formation mechanisms in Ti alloys using atomistic simulations and first-principles calculations; (ii) upscaling the atomistic mechanisms of microstructure evolution to macroscopic mechanics through phase-field finite element modeling; and (iii) developing cross-phase-boundary thermomechanical pathways to control the formation of microstructures in Ti alloys. The project will advance the fundamental understanding and modeling of microstructure evolution in Ti alloys, accelerating the development of thermomechanical processing approaches and alloy compositions of Ti alloys. This project will tightly integrate research and educational activities, including science exhibits, curriculum development, research mentoring, online education, and research tool sharing, with an overarching theme of “strong and ductile metal alloys” to train a diverse body of students at the K-12, undergraduate, and graduate levels toward fostering a scientific workforce with integrated knowledge of materials and mechanics. The project will make the developed education modules and research tools accessible to both online and in-person participants.This project is jointly funded by the Division of Materials Research (through the Condensed Matter and Materials Theory and Metals and Metallic Nanostructures programs) and the Division of Civil, Mechanical, and Manufacturing Innovation (through the Mechanics of Materials and Structures program).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.