Molecular dynamics simulation of the nanoindentation process in Cr/CrN and (Cr/CrN)2 thin films

Abstract

Molecular dynamics (MD) simulations were carries out for studying the influence of nanoindentation in the atomistic deformation mechanisms of Cr/CrN and (Cr/CrN)2 coatings with BCC and FCC crystalline structures for Cr and CrN, respectively. The Morse potential was employed in order to determine the atomic interaction forces of the Cr-Cr and Cr-N atoms. A non-deformable potential solid sphere was implemented for determining the role of the nanoindenter. The Oliver-Parr method (OP) was used to obtain the hardness and elastic modulus of the Cr/CrN and (Cr/CrN)2 layers, resulting in values of 18 and 20 GPa for Cr/CrN and (Cr/CrN)2, respectively. The Cheng method was used for correcting the hardness values obtained by the OP method. The Cheng correction showed higher hardness values since it avoids the influence of the scale effect. Regarding the elasticity modulus, Cr/CrN and (Cr/CrN)2 exhibited values of 217.86 GPa and 258.9 GPa, respectively. Simulations of the temperature influence on the hardness were carried out over a range of 300-1000 K. Results indicate that the hardness decreased as a function of the temperature. 4618 S. Amaya-Roncancio et al.

Modeling the Deposition of Thin Films of Transition Metal Nitrides

“…In [71], a computational model based on the MD method for simulation of the process of nanoindentation of solid materials using Morse pair potential was developed. This model was employed to replicate the mechanical characteristics of thin film systems that comprise Cr/CrN and (Cr/CrN) 2 .…”