6. Conclusions, issues, and future work
6.2. Issues and future work
The proposed model based on the Monte Carlo Potts model offers the materials phenomena of solid-state sintering, but it spends much time on the simulations for large size domains because rates of pore shrinkage are definitely reduced when pores are migrated along grain boundaries and incorporated with each other by hetero-interface diffusions and breakaway of pinned grain boundaries for complicated systems composed of numerous particles. It is noticeable that the developed packages for solid-state sintering needs to be expanded to the parallelization computation. The penetration of the outer vapor phase was prohibited by using the “Burn algorithm” for ideal solid-state sintering, but this spends long time on computations because all solid-spin pairs are subject to inspect whether the penetration occurs or not in this work. In the later study, the outer vapor phase will be allowed to be transferred without any constraint conditions, leading to increase in the volume of inner vapor phase in order to embody the realistic mass transportation of sintered materials. Moreover, the anisotropy of the grain boundary energies will be introduced for the simulation of real materials.
Before microstructures of the real materials are utilized as inputs, sintering behavior will be examined for the simple structures with large size in three dimensions. For example, simple structures where a spherical pore lying on a grain boundary between half-sphere grains and contacting three wires elongated along the z direction were prepared as illustrated in Chapter 2. The sintering simulations of the expanded structures in three dimensions will represent slightly different densification behavior from two dimensions because vacancies will be detached from hetero interfaces along a couple of directions (i.e., vacancies will be detached onto the grain boundary plane whenever the hetero interfaces make the locally equilibrated shape) and volume of pore of columnar structures among contacting three wires can be increased by the hetero-interface diffusions and vacancy supply along the elongated direction, resulting in complicated morphological transformation and changes in the sintering kinetics. These issues will be explored in the future.
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