THE EFFECT OF INITIAL VOID CONFIGURATION ON THE MORPHOLOGICAL EVOLUTION UNDER THE ACTION OF NORMALIZED ELECTRON WIND FORCES

Ersin Emre OREN and Tarik O. OGURTANI
Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06531, Turkey

In these studies a comprehensive picture of void shape evolution dynamics and its strong dependence on the initial configuration has been thoroughly investigated by utilizing hypocycloid algebra to generate four different shapes of main interest. Our mathematical model on the isotropic diffusion and mass accumulation on void surfaces, under the action of applied electrostatic potential and capillary effects, follows a novel irreversible but discrete thermodynamic formalism of interphases and surfaces.

As a result during the intragranual motion, in addition to the crescent–like slit formation, very rich and also unusual void morphological variations such as fragmentations into the daughter voids or inner island generation have been observed under the severe (normalized) electron wind intensities or very long exposure times. In these numerical experiments, the Euler’s method of finite differences with an automatic time step self-adjustment has been utilized in combination with a rather powerful and fast boundary element method (BEM) for the solution of the Laplace equation.