Nanoscale Self-Organization In Alloys Driven By Irradiation And Plastic Deformation

Pascal Bellon, Associate Professor of Materials Science and Engineering, UIUC

Materials are often driven into nonequilibrium states either during their processing or in service. Examples of such forcing situations are found in alloys subjected to energetic particles, for instance during thin film growth or in a nuclear reactor, and alloys subjected to sustained plastic deformation, for instance during powder processing or during dry sliding wear. A remarkable property of these dissipative alloy systems is their ability to self-organize, often at the nanometer scale. Using continuum kinetic modeling and atomistic simulations, we have shown that a key requirement for self-organization to take place it that the disorder created by the external forcing introduces length scales that differ from the ones involved in the annealing of that disorder by thermally activated processes. We will present recent modeling and simulations results, as well as experimental tests, on the self-organization of alloys subjected to sustained irradiation or sustained plastic deformation. These results suggest that external forcing can be used to synthesize nanoscale structures with tunable lengthscale for improved mechanical or magnetic applications.

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