摘要
The role of grain-boundary (GB) in the melting for Sigma=5 bicrystals of B2 NiAl is investigated by molecular-dynamics simulation. The thermodynamic properties of the boundary are monitored over a wide temperature range including the thermodynamic melting point T-m which is determined by using a many-body potential fitted to NiAl. A thermal disorder transition in the GB region occurs well below the melting point. Our results indicate that such a transition is a continuous process and there is no evidence of premelting, which is entirely in accord with experimental results and theoretical prediction. Moreover, we also find that the superheated temperature range of this intermetallic alloy is much wider than that of some elemental metals.
The role of grain-boundary (GB) in the melting for Sigma=5 bicrystals of B2 NiAl is investigated by molecular-dynamics simulation. The thermodynamic properties of the boundary are monitored over a wide temperature range including the thermodynamic melting point T-m which is determined by using a many-body potential fitted to NiAl. A thermal disorder transition in the GB region occurs well below the melting point. Our results indicate that such a transition is a continuous process and there is no evidence of premelting, which is entirely in accord with experimental results and theoretical prediction. Moreover, we also find that the superheated temperature range of this intermetallic alloy is much wider than that of some elemental metals.
