Simulation and analysis of the local atomic structure for melting behavior in metals

Melting is a phase transition from topological order to disorder, leading a solid to transform into a liquid state. However, the microstructural principles governing the melting behavior of metals, particularly during the melting process, remain unclear. This study adopts molecular dynamics simulations to investigate the atomic structure during the melting process of metals, taking Cu as an example. The effects of crystal orientations, surfaces, and surface energies on the anisotropy of the melting point are discussed. Furthermore, the similarities and differences are described between pre–melting, surface melting, and bulk melting in Cu. The investigation addresses superheating issues arising from the inhomogeneous nucleation of crystal defects and the homogeneous nucleation of perfect crystals. Finally, a detailed exploration of the transition in the local atomic structure and the dynamic behavior of Cu atoms is conducted, utilizing the mean square displacement, diffusion coefficient, radial distribution function, and polyhedral template matching.