Study of grain boundary self-diffusion in iron with different atomistic models
S. Starikov, M. Mrovec, R. Drautz.
Acta Materialia, 188, 560-569, (2020)
We studied grain boundary (GB) self-diffusion in body-centered cubic iron using ab initio calculations and molecular dynamics simulations with various interatomic potentials. A combination of different models allowed us to determine the principal characteristics of self-diffusion along different types of GBs. In particular, we found that atomic self-diffusion in symmetric tilt GBs is mostly driven by self-interstitial atoms. In contrast, in general GBs atoms diffuse predominantly via an exchange mechanism that does not involve a particular defect but is similar to diffusion in a liquid. Most observed mechanisms lead to a significant enhancement of self-diffusion along GBs as compared to diffusion in the bulk. The results of simulations are verified by comparison with available experimental data.
Keyword(s): iron; diffusion; grain boundary; interatomic potentials
Cite as: https://www.sciencedirect.com/science/article/abs/pii/S1359645420301312