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.