Faceting diagram for Ag segregation induced nanofaceting at an asymmetric Cu tilt grain boundary

In this work, we experimentally establish the isothermal nanofacet evolution at an asymmetric Sigma 5 tilt grain boundary in the Cu-Ag system using a diffusion couple approach. We investigate the nanofacet formation along the grain boundary in dependence of the Ag solute excess concentration. The initial grain boundary dissociates into asymmetric Ag-lean segments and Ag-rich symmetric (210) segments. Increasing Ag excess leads to an increase in Ag-rich facet segment length, while the length of the asymmetric facets remains constant. From this, we construct a grain boundary nanofaceting diagram deduced from our experiments relating local atomic structure, overall inclination and Ag solute excess. (C) 2021 The Author(s). Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Automated summary

Experimental results show that the isothermal nanofacet evolution occurs at an asymmetric Sigma 5 tilt grain boundary in the Cu-Ag system, where the excess of Ag solute affects the length of Ag-rich facet segments, while the length of asymmetric facets remains constant. A grain boundary nanofaceting diagram constructed from experimental data explains the relationship between local atomic structure, overall inclination, and Ag solute excess.