Event № 102
Professor Amy Novick-Cohen
If we look at most materials under a microscope, we will see a network of grains and grain boundaries as well as holes, cracks, cavities and additional various defects. These features determine the microstructure of the material, whose properties are crucial in determining the various mechanical, electric, magnetic, and optical properties of the material. The microstructure is in turn influenced by the evolution of the exterior surface via the grain boundaries.
In my lecture I shall report on 3D numerical studies of the motion of quadruple junctions and thermal grooves in thin polycrystalline films where the mean curvature motion of the grain boundaries and the surface diffusion evolution of the exterior surfaces couple along the thermal grooves. Our algorithms could also be used to study hole evolution in thin monocrystalline and polycrystalline films, where only the motion of the exterior surface needs to be considered.
To describe the physical models and their motion, we used a system of partial differential algebraic equations with boundary and initial conditions. Our numerical approach used a finite difference scheme on a staggered grid with partially parallelized numerical algorithms, the backward Euler method, and Newton’s method.. Simulations, written in MATLAB and ”C”, were able to indicate some new instabilities.