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Full-Text Articles in Engineering
Simulation Of Plasticity In Nanocrystalline Silicon, M. J. Demkowicz, A. S. Argon, D. Farkas, Megan Frary
Simulation Of Plasticity In Nanocrystalline Silicon, M. J. Demkowicz, A. S. Argon, D. Farkas, Megan Frary
Materials Science and Engineering Faculty Publications and Presentations
Molecular dynamics investigation of plasticity in a model nanocrystalline silicon system demonstrates that inelastic deformation localizes in intergranular regions. The carriers of plasticity in these regions are atomic environments that can be described as high-density liquid-like amorphous silicon. During fully developed flow, plasticity is confined to system-spanning intergranular zones of easy flow. As an active flow zone rotates out of the plane of maximum resolved shear stress during deformation to large strain, new zones of easy flow are formed. Compatibility of the microstructure is accommodated by processes such as grain rotation and formation of new grains. Nano-scale voids or cracks …
Correlation-Space Description Of The Percolation Transition In Composite Microstructures, Megan E. Frary, Christopher A. Schuh
Correlation-Space Description Of The Percolation Transition In Composite Microstructures, Megan E. Frary, Christopher A. Schuh
Materials Science and Engineering Faculty Publications and Presentations
We explore the percolation threshold shift as short-range correlations are introduced and systematically varied in binary composites. Two complementary representations of the correlations are developed in terms of the distribution of phase bonds or, alternatively, using a set of appropriate short-range order parameters. In either case, systematic exploration of the correlation space reveals a boundary that separates percolating from nonpercolating structures and permits empirical equations that identify the location of the threshold for systems of arbitrary short-range correlation states. Two- and three-dimensional site lattices with two-body correlations, as well as a two-dimensional hexagonal bond network with three-body correlations, are explored. …
Determination Of Three-Dimensional Grain Boundary Connectivity From Two-Dimensional Microstructures, Megan Frary
Determination Of Three-Dimensional Grain Boundary Connectivity From Two-Dimensional Microstructures, Megan Frary
Materials Science and Engineering Faculty Publications and Presentations
The connectivity of so-called "special" and "general" grain boundaries at a quadruple node is known to be nonrandom as a result of crystallographic constraints. Although a quadruple node is a three-dimensional feature, there exist two-dimensional features which are topologically identical. Therefore, the distribution of these two-dimensional features may be used to determine the three-dimensional connectivity. Computer simulations of a three-dimensional microstructure which is virtually serial sectioned are used to validate the proposed approach.