A scientific framework will be established for field processing of nanosize particulate materials. In particular, a detailed theoretical-experimental program will be pursued with specific goals to: (a) evaluate and clarify the interdependence of material properties, geometry of microstructure and processing parameters of nanosize powders, (b) quantify the conduction of electric current through sintering nanopowder compacts and relate them to manufacturing and properties, and (c) develop a process design/characterization methodology for this technology that is applicable to nanocrystalline materials for large and net shape parts. This project will: (a) generate fundamental knowledge of the role of size scale in field processing, (b) elucidate specific mechanisms responsible for the enhanced performance of field sintering, (c) provide a rational basis for process design and optimization of this process, (d) provide guidance for the development of new models for design of complex shape processing in terms of optimization of current application, as well as die design. In addition, we will generate sizable specimens of nanocrystalline materials that will be extensively characterized for structure, defects and mechanical properties. Structural materials with grain size less than 100 nm are characterized by unusually high strength, hardness and wear resistance, as well as good fatigue resistance. This project focuses on the manufacturing and characterization of bulk nanocrystalline materials produced by field assisted sintering that can produce near net-shape bulk components starting from nanosize powders, and retains the scale of the microstructure during processing. The development of a scientific processing base for manufacturing of bulk nanoscale materials will be a major step towards commercialization of this exciting new class of materials which preserve nanometric grain size and combine unusual properties. This collaborative proposal between two Universities will provide a synergistic effect to enhance both modeling performed at Drexel University and nano-process understanding by experiments at University of California Davis. The integration of education and training within the research program will be achieved by developing a seminar course for Drexel and UCD students on "Manufacturing of bulk nanomaterials". We will continue involving undergraduate students in research by REU supplements.
