Nanoscale Interdisciplinary Research Teams (NIRT): Superhard Nanostructured Films

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This Nanoscale Interdisciplinary Research Team (NIRT) project will be conducted by a team that includes researchers on fracture micromechanics, characterization of structure and interfaces, plasma technology, aerosol technology, and microfabrication, together with collaborators at Los Alamos and Sandia National Laboratories. Evidence from a number of studies suggests that it should be possible to produce nano-crystalline composites that are superhard possessing hardness rivaling diamond and that also possess other properties that make them superior to diamond for applications requiring friction and wear resistance. A novel approach is proposed for synthesizing such materials, based on plasma synthesis and deposition of nanoparticles. The synthesis tool will be hypersonic plasma particle deposition, in which nanoparticles nucleate in thermal plasma and are then accelerated, in a hypersonic expansion, causing them to deposit by high-velocity impact. Nanocomposite films will be deposited with grain sizes in the range 5 to 10 nm, comprised of various combinations of the elements boron, carbon, nitrogen, silicon and titanium. In separate experiments, aerodynamic lenses will be used to focus the nanoparticles to collimated beams. These beams will be used in conjunction with microfabrication techniques to demonstrate fabrication of Micro-Electro-Mechanical System (MEMS) devices from nanoparticles.These synthesis studies will be supported by fundamental studies of structure-property relations. The structure, crystallinity, chemical composition and deformation behavior of the synthesized material will be characterized at length scales ranging from the atomic level to individual nanosized grains, to interfacial regions, to the entire film. In addition to these experimental studies, numerical simulations of nanoparticle deformation at the atomistic scale will be performed in the context of both the processing and the subsequent mechanical performance. The highly interdisciplinary, highly interactive environment between two academic departments, several laboratories, and collaborators from Los Alamos and Sandia National Labs will provide graduate and undergraduate students with a breadth of experience in nanomanufacturing and nano-materials characterization. In additions, K-8 students involved in the NSF-supported ScienceWorks Program will be provided the opportunity to experience this novel research area.