Melting of the Symmetrical Tilt Boundaries in Copper

Abstract

The melting transition in three high-energy and two low-energy fcc Cu symmetrical tilt grain boundaries (STGBs) has been investigated by molecular-dynamics (MD) simulations. Low-energy STGBs are found to be crystalline from room temperature all the way up to T₀ (T₀ is the thermodynamic equilibrium melting point). In contrast, all high-energy STGBs undergo premelting which is initiated at a transition temperature T_c (T_c<T₀). Moreover, the higher the zero-temperature GB energy, the lower the T_c.