Grain-boundary plane orientation dependence of faceting-roughening transition in Au grain boundaries under electron-beam irradiation

Grain boundaries act to absorb and annihilate point defects generated by high-energy particles for poly-crystalline nuclear materials. Thus, understanding the effect of irradiation of high-energy particles on the grain-boundary structural change is prerequisite to develop nuclear materials with desirable properties. It is expected that such an effect would be different for different GB characters. To explore the probability, we examine grain boundaries with twist and tilt components with the same misorientation relationship of [1 0 0]/45 degrees in Au as a model system at a high-voltage transmission electron microscope with an acceleration voltage of 1250 keV. It is observed that, under the same irradiation condition, the tilt GB undergoes roughening while the twist one became faceted. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

The irradiation of high-energy particles can affect the grain-boundary structure of polycrystalline nuclear materials, with different reactions observed for different grain-boundary characteristics. By examining different types of grain boundaries in a model system, it was found that tilt boundaries became roughened while twist boundaries became faceted under the same irradiation conditions.