A Molecular Dynamics Study on the Early Stage Oxidation Behavior of Nickel Surface in Oxygen and Water Environments

There were many efforts to investigate the nature of oxidation and corrosion behavior of the nickel in atomistic or sub-atomistic scales because understanding of the nature of oxide film formed metal/gas or metal/water interfaces is one of the key parameters to understand the mechanism of SCC. In other words, regardless of the importance of understandings on their base mechanism, still it remains as unexplored area. Computational simulation methods are gathering numerous interest from assorted science and engineering fields because it can overcome the experimental barrier such as scale, spatial limitations, etc and obtain detailed instructions such as a bond length between oxygen and metal atoms, a diffusivity, and electron density absorption energy and so on. This work was conducted to investigate the early stage oxidation in order to understand the fundamental oxidation behavior of nickel by using molecular dynamics. The LAMMPS was used for the molecular dynamics calculation. The ReaxFF potential was used to calculate the interatomic force between nickel, oxygen and hydrogen atoms. In the results, oxygen atoms were infiltrated into the nickel surface and interact with neighboring nickel atoms. In additional to, this nickel oxide layer is formed distorted trigonal system by interaction between oxygen and nickel atom.