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A Fractal Dimension Based Approach to Decipher Grain Boundary Chemomechanics at Quantum Scale

You Sung Han (), Vikas Tomar (Purdue)

From Atomistics to Reality: Spanning Scales in Simulations and Experiments Symposium B

Wed 1:30 - 2:50

CIT 227

The effect of primary knock on atom (PKA) induced damage on the peak tensile strength of cubic silicon carbide (3C-SiC) is examined using an ab initio simulation framework based on Car Parrinello Molecular Dynamics (CPMD). The framework examins the effect of damage caused by a PKA with velocities corresponding to four different radiation energy levels (50 eV, 500 eV, 1 keV, and 2 keV) in three different SiC nanostructure samples with different grain boundary (GB) configurations. It is found that the peak tensile strength of the examined nanostructures is a function of change in temperature, radiation energy, and GB configuration. In order to extend the observed correlation of the peak tensile strength with atomic configurations to other nanostructure types, a fractal dimension based approach is adopted to predict nanostructure peak tensile strength as a function of radiation energy, temperature, and GB configuration. Analyses show that the tensile strength of the examined SiC nanostructures increases as a function of their fractal dimension increase. Fractal dimensions also change as a function of change in radiation energy level and the corresponding damage in an inversely proportional manner. Based on observed correlations, an empirical relation to predict nanostructure peak tensile strength as a function of simulation parameters is developed. The developed relation is found to predict strength data of nanostructures not included in the fitting with good accuracy.