Additive Manufacturing of Load and Energy Absorbing Materials through an Integrated Experimental and Modelling Approach

这个多PI先进制造项目旨在了解和探索氧化锆陶瓷在铜和钢金属基体中的相变机制。氧化锆可以将大的机械应变转化为可恢复的热，但这种潜力尚未被探索用于金属基复合材料。此外，该项目还研究了一种新的基于摩擦的增材制造工艺MELD，目标是开发新的能量和应力吸收部件。将对通过MELD创建的相应材料进行多尺度计算机建模。模拟结果将与实验数据进行比较，以更好地理解MELD制造过程中的微观结构演变和基础设施使用过程中的组件行为。从实验和建模工作的综合理解，预计将带来新的能力，为基础设施的改善和维修。由于其广泛的适用性，这种制造工艺可以直接影响建筑物，飞机和汽车承受苛刻负载的能力，因此直接影响美国的经济福利和国家安全。所产生的知识将广泛传播给科学界，公众和K-12学生。我们还将通过将最相关的技术和社会问题带到教室/实验室来丰富我们目前的课程。PI/Co-PI将领导广泛的外联工作，以增加STEM中女性和少数民族的入学率。具体的工作包括参加夏令营，重点是代表性不足的学生，与少数服务机构的合作，并通过西弗吉尼亚州的科学博物馆外展活动。这项研究将研究一种新型的金属基复合材料，利用一种独特的应力和能量耗散机制的基础上氧化锆马氏体相变。将研究一种新的可扩展的增材制造工艺-MELD的基本原理，并将集成多尺度和多物理模拟，以增强对微观结构-性能的理解和预测。理论工作将与原位和非原位微观结构表征和性能评价结果相关联。研究方法是：1）研究金属基复合材料中的应力/能量耗散机制，以提高不同长度尺度下结构的弹性，2）了解复合材料合成和添加剂沉积变量的影响，并对MELD期间的热/质量流过程进行基本了解，以创建新结构并实现新性能，3）模拟MELD期间的质量和热量流动，并预测在循环载荷和能量冲击条件下多尺度下的微观结构衍生性能，以及4）建立应力/能量吸收能力与氧化锆增强的金属复合材料合成和MELD制造之间的定量关系。该项目将详细了解金属基体中氧化锆独特且可逆的相变，特别是其在能量和应力吸收方面的功能。它还将提供MELD的基础知识，这是一种基于摩擦搅拌方法的令人兴奋的可扩展增材制造工艺，并创造近净形和全致密金属基复合材料。该研究还将推进MELD过程中和MELD过程后的质量流和热流的多尺度、多物理场模拟，同时深入了解复杂载荷条件下MELD使能复合材料的结构行为。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This multi-PI advanced manufacturing project aims to understand and explore phase transformation mechanisms of zirconia ceramic in copper and steel metal matrices. Zirconia can convert large mechanical strain into heat recoverably but this potential has not been explored for metal matrix composites. In addition, the project studies a new friction-based additive manufacturing process, MELD, with the goal of developing new energy- and stress-absorbing components. Multi-scale computer modeling of the corresponding materials created through MELD will be carried out. Simulation results will be compared with experimental data for improved understanding of microstructure evolution during the MELD manufacturing process and the component behaviors during infrastructure use. The integrated understanding from the experimental and modeling efforts is expected to bring in new capabilities for infrastructure improvement and repair. Because of its broad applicability, this manufacturing process can directly impact the ability of buildings, aircraft, and automobiles to withstand demanding loads, and therefore directly impacts the economic welfare and national security of the United States. The knowledge generated will be widely disseminated to the scientific community, to the general public, and to K-12 students. We will also enrich our current curricula by bringing the most relevant technical and societal issues to classrooms/labs. The PI/Co-PIs will lead extensive outreach efforts to increase the enrollment of females and minorities in STEM. Specific efforts include participation in summer camps that focus on underrepresented students, collaboration with a minority serving institution, and outreach activities through Science Museum of Western Virginia.This research will study a novel type of metal matrix composites by leveraging a unique stress and energy dissipation mechanism based on zirconia martensitic phase transformation. The fundamentals of a new and scalable additive manufacturing process--MELD will be investigated, and multi-scale and multi-physics simulations for enhanced microstructure-property understanding and prediction will be integrated. The theoretical work will be correlated with both in-situ and ex-situ microstructure characterization and property evaluation results. The research approaches are: 1) study stress/energy dissipation mechanisms in metal matrix composites to improve the resilience of structures at different length scales, 2) understand the influence of the composite synthesis and additive deposition variables, and develop fundamental understanding of the heat/mass flow processes during MELD in order to create new structures and enable new properties, 3) simulate mass and heat flows during MELD and predict microstructure-derived performance at multi-scales under cyclic loading and energy shock conditions, and 4) build quantitative relations between the stress/energy absorbing capabilities and zirconia-enhanced metal composite synthesis and MELD manufacturing. This project will provide detailed understanding to the unique and reversible phase transformation of zirconia in metal matrices, especially regarding its functions in energy and stress absorption. It will also offer fundamental knowledge in MELD, an exciting and scalable additive manufacturing process based on friction stir methods, and create near net shape and fully-dense metal matrix composites. The research will also advance multi-scale, multi-physics simulations of mass flow and heat flow during the MELD process and after the MELD process while providing insight into the structural behaviors of the MELD-enabled composites under complex loading conditions.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.