Investigation of Deformation Behavior of High Entropy Alloy Coated Fcc Metallic Systems under Nanoindentation Using Molecular Dynamics Simulation

Abstract

The face-centered cubic (FCC) structured metallic systems such as Al, Cu, Ni, and their alloys have frequently undergone through various challenges and difficulties under high temperature, extensive wear, heavy load, oxidation, and corrosion, etc. conditions in advanced structural and functional applications. So, in the present study, the high entropy alloy (HEA) coating has been developed over the single crystal (SC) FCC metallic substrates such as Ni, Cu, and Al with the help of molecular dynamics (MD) simulation at 1 K temperature to enhance their performance and durability under the harsh conditions. Further, the nanoindentation test has been performed over the HEA coated SC FCC specimens to characterize their mechanical properties using MD simulation. At the beginning of nanoindentation test, the compressive shear stress has been developed around the indenter tip. As the indentation process is going on, the accumulative compressive shear stress has subsequently increased. When this accumulative stress exceeds the critical resolved shear stress (CRSS) value, then it emancipates in the preferred slip systems to release the excess stress in terms of structural deformation. The structural analyses such as centrosymmetry parameter (CSP) analysis, common neighbor analysis (CNA), and radial distribution function (RDF) plots have been used to visualize and analyze these structural deformation activities during the nanoindentation process to get more detailed information and a better understanding of the underlying deformation physics.