The project addresses key aspects of the manufacturing of bulk nanocomposite materials based on repeated rolling and folding of arrays of metal foils, metal/polymer multilayers, and nanocrystal/metallic glass composites. Aside from a systematic examination of processing parameters, the project concentrates on the coupled dynamic evolution of transformation sites such as interfaces or shear bands and atomic scale phenomena such as driven mixing or driven crystallization. Upon identifying common characteristics of the different material systems, a general theoretical framework will be developed for the microstructure evolution of two-phase microstructures under intense deformation. In addition to standard microstructural analysis techniques, marker experiments will be conducted for multilayers to identify microstructural changes that can not be identified by electron microscopy. The experimental work will be supported by theoretical efforts to model diffuse necking for the multilayers. The reproducibility of microstructures will be gauged with a Weibull-type analysis. The results will help identifying energy and time efficient processing conditions for the synthesis of bulk nanocomposite materials. The project results support two long-term outreach efforts. Continuing the collaboration with the Connecticut Pre-Engineering Program (CPEP), hands-on demonstrations for workshops based on multilayer deformation will be developed for mostly underrepresented and women middle-school students and for middle-school teachers in CT. The broader impact of the project furthermore derives from demonstrations for high-school students as part of a "Materials Road Show". Using a portable hand rolling mill, for example, nanocomposites will be synthesized to introduce nanotechnology aspects of materials science to high-school students.
