Computational insights and phase transitions of ruthenium alloy using classical molecular dynamics


Evolution in melt structures with temperature during deep undercooling, forming uniform melt-free crystal sites, and the effect of the melt state on solidification behaviors by using embedded atom method (EAM) potential, all have theoretical significance for understanding the mechanism of metal solidification. This EAM potential has remarkable accuracy and a wide range of properties, including mechanical properties, lattice dynamics, the energetics of competing crystal structures, defects, deformation routes, and liquid structures. In this study, we have performed a molecular dynamics simulation to examine the impact of different cooling rates during melt Ruthenium (Ru) alloy’s solidification at temperatures ranging from 3250 K to 50 K. The evolutions in local systems have been observed in an energy-temperature curve, pair-correlation functions, bond angle distribution functions, the Honeycutt-Anderson index, and visualization analysis. Upon quenching with different cooling rates, we have observed transformation to a supercooled liquid state at 1200 K and a body-centered cubic-like cluster dominated after 1200 K in a stable and supercooled liquid form. We have calculated a critical cooling rate (1012 K/s) for the crystal to amorphous transition, and the solidification under cooling increases being the superheating temperature accelerates until the maximum cooling is achieved. We have found that the maximal undercooling occurred approximately at 0.4396Tm K and the maximal superheating at 1.2893Tm K. In our simulated data, the first and second peaks of radial distribution function(RDF) at room temperature show fair accordance with the experimentally observed RDF peaks of Ru nanoparticles. These findings will provide a roadmap and a foundation for further research on the relationship between melt temperature and nucleation supercooling.

2023 KPS Spring Meeting (04/19-04/21, Daejeon)