First principles study on the segregation of metallic solutes and non-metallic impurities in Cu grain boundary

Abstract: Metallic dopants have the potential to increase the mechanical strength of polycrystalline metals. These elements are expected to aggregate in regions of lower coordination, such as grain boundaries. At the grain boundaries, they can have a beneficial (toughening) or detrimental effect (e.g. grain boundary embrittlement). In this study, we employ Density Functional Theory (DFT) to compute the segregation energies of various metallic and other non-metallic elements to determine their effect when introduced in a symmetric Cu grain boundary. The study results may be used to qualitatively rank the beneficial effect of certain metallic elements, such as V, Zr, and Ag, as well as the strong weakening effect of non-metallic impurities like O, S, F and P. Furthermore, the induced local distortion is found to be proportional to the weakening effect of the elements.