Principal physical parameters characterizing the interactions between irradiation-induced point defects and several tilt symmetric grain boundaries in Fe, Mo and W

Abstract

Using molecular-statics, we investigate principal physical parameters characterizing the binding of vacancies and interstitials with grain boundaries (GBs), and their annihilation near GBs in iron, molybdenum and tungsten. Binding energies strongly correlate with GB energies averagely and have a general level when scaled by the bulk defect formation energy. Defect diffusion is enhanced near the GB. The diffusion barrier of the vacancy gradually decreases as it approaches to the GB. For interstitials, there exist several layers near the GB in which the absorption of interstitials is spontaneous and out of which orientation-dependent. For the interstitial-rich GB, the vacancy near the GB can be annihilated at a low barrier, independent of the system. The GB influence range is limited of 1.0–2.0nm from the GB. Our obtained principal physical parameters may be applied to build the master framework for defects’ generation, transport and fate and thus to evaluate the damage rate in nano/poly-crystalline materials.