Molecular dynamics simulation for microscope insight of water evaporation on a heated magnesium surface

Increasing demands for lightweight heat pipes have been seen in recent years. Magnesium (Mg) as one of the lightest metals in the world attracts researchers to utilise it to make heat pipes, but due to the active chemical properties of Mg and its alloys, its compatibility with working fluid has become a major problem. In this paper a numerical simulation based on the molecular dynamics (MD) method is conducted to study the evaporation of water from a heated Mg surface, aiming to get a microscopic insight of such a liquid–vapour–solid system and understand the effect of the hydrogen bond on water molecules during the evaporation or nucleate boiling. The results of the MD simulation indicate that the evaporation process of water on Mg surface is actually a process of water molecules migration and the numbers of water molecules changing with Mg surface temperature. In addition, the corrosion of the magnesium alloy in water and the incompatibility are analysed; and an MD simulation of the interactions between water molecules and magnesium molecules has been carried out. The MD simulation also shows the effect of the hydrogen bond on the behaviour of water molecules during evaporation.