Increase of Grain Boundary Mobility by Radiation Damage under Thermal Gradient Condition using Molecular Dynamics Simulation

Most transformations of microstructure, such as recrystallization, grain growth are based on migration of grain boundaries. These transformations greatly influence on thermal, electrical transport and mechanical properties of materials. Material industries always set aim to design and produce decent materials by controlling microstructure evolution under various conditions. Since understanding grain boundary migration is critical for predicting the microstructural evolution in material, it has been very widely investigated for several decades. Also simple information from GB migration can give the clue to depict complicated and scale-up microstructural evolution. In this work, we investigated the grain boundary migration after the radiation damage. Without radiation damage, thermal gradient driving force was insufficient to cause the movement of grain boundary. However, with introduction of radiation damage, grain boundary showed the migration behavior while it is restored from damaged state. This is due to the fact that kinetic energy of energetic particles trigger the migration of GB by increasing temperature at GB region enormously. Rapid collision supplies the energy to exceed energy barrier to make the movement of migration As temperature of local region goes up due to radiation damage, mobility of GB should rise according to the eq.2. Therefore, radiation damage act as the trigger of local gratin boundary migration