TY - JOUR

T1 - Nanoindentation in alumina coated Al

T2 - Molecular dynamics simulations and experiments

AU - Luu, Hoang Thien

AU - Raumel, Selina

AU - Dencker, Folke

AU - Wurz, Marc

AU - Merkert, Nina

N1 - Funding Information: The authors gratefully acknowledge for supports from Simulation Science Center Clausthal/Göttingen. The project was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) — Project-ID 394563137-SFB 1368 . N.M. acknowledges funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, GU 1530/6-1 ). The work was supported by the North-German Supercomputing Alliance (HLRN). H.-T.L. gratefully acknowledges Dr. V-X Tran, Dr.-Ing. Sandeep P. Patil for useful conversations and the authors thank Dr. David Mercier for important discussions on size effects during indentation.

PY - 2022/5/15

Y1 - 2022/5/15

N2 - Oxygen is often a significant disruptive factor in many production engineering processes and efforts have been made to limit or remove these oxide layers during manufacturing. However, the mechanical properties of oxide layers and their relationship to the raw material are not yet fully understood. In this work, we examine the nanoindentation process on Al surfaces covered with a native oxide layer of various thicknesses using molecular dynamics (MD) models and experiments. For MD simulations, the most advanced interatomic potentials, COMB3 and ReaxFF, are employed to model the interaction between Al and O elements. The two potentials were thoroughly tested and compared with the Embedded Atom Method (EAM). According to our findings, the oxide layer has a significant impact on defect emission in the substrate. However, the behavior of the oxide layer during the indentation process is different for the two potentials. In agreement with experiments, the COMB3 potential shows crack initiation and propagation. The ReaxFF potential displays a pile-up of atoms surrounding the indenter, but no cracks are visible.

AB - Oxygen is often a significant disruptive factor in many production engineering processes and efforts have been made to limit or remove these oxide layers during manufacturing. However, the mechanical properties of oxide layers and their relationship to the raw material are not yet fully understood. In this work, we examine the nanoindentation process on Al surfaces covered with a native oxide layer of various thicknesses using molecular dynamics (MD) models and experiments. For MD simulations, the most advanced interatomic potentials, COMB3 and ReaxFF, are employed to model the interaction between Al and O elements. The two potentials were thoroughly tested and compared with the Embedded Atom Method (EAM). According to our findings, the oxide layer has a significant impact on defect emission in the substrate. However, the behavior of the oxide layer during the indentation process is different for the two potentials. In agreement with experiments, the COMB3 potential shows crack initiation and propagation. The ReaxFF potential displays a pile-up of atoms surrounding the indenter, but no cracks are visible.

KW - Alumina

KW - Aluminum

KW - Hardness

KW - Molecular dynamic simulations

KW - Nanoindentation

KW - Native oxide layer

UR - http://www.scopus.com/inward/record.url?scp=85126835473&partnerID=8YFLogxK

U2 - 10.1016/j.surfcoat.2022.128342

DO - 10.1016/j.surfcoat.2022.128342

M3 - Article

AN - SCOPUS:85126835473

VL - 437

JO - Surface and Coatings Technology

JF - Surface and Coatings Technology

SN - 0257-8972

M1 - 128342

ER -