The NIRT research program is to advance both the fundamental understanding and knowledge of ultrasonic cavitation based solidification processing of complex bulk magnesium-based metal-matrix nanocomposite materials/components and their processing/structure/property relationships. Six interrelated research tasks are planned. In Task 1, a functional experimental system for ultrasonic cavitation based casting will be developed to demonstrate scalability for high volume production. Task 2 focuses on the understanding of the process by monitoring transient cavitation activities and on the optimization of the process to achieve uniform nanoparticle dispersion in Mg melt. Task 3 is to characterize the micro/nano structure of the resultant nanocomposites. The dislocation structure in the matrix around nanoparticles will be examined to understand the mechanism of strengthening by nanoparticles. Task 4 will perform multi-scale modeling of cast Mg nanocomposites to develop a fundamental and quantitative understanding of how the nanoscale structure influences properties. Task 5 will experimentally characterize the effect of nanoparticles on the mechanical properties (at elevated temperatures as well as at room temperature) of cast Mg matrix nanocomposites by tensile, creep, in-situ deformation and fatigue studies, nano-indentation, fracture-toughness, and tool-wear testing. Task 6 is to establish the processing/structure/property relationships by correlating the ultrasonic cavitation activities with the results from the experimental and analytical studies. Cast bulk Mg alloy matrix nanocomposites can have a widespread impact on the automobile and aerospace industries by significantly improving the vehicle energy efficiency and performance. The educational components include multi-campus curriculum development at University of Wisconsin-Madison, University of California-Davis, and Georgia Institute of Technology, research student exchange, and a Nanotechnology Awareness Program (NAP) to attract and engage students (from colleges and high schools) and Technology Education teachers, especially those from underrepresented groups. Outreach activities will expose more K-12 students, teachers, and industries to nanotechnology.
