Open Access

ARTICLE

Determination of Temperature-Dependent Elasto-Plastic Properties of Thin-Film by MD Nanoindentation Simulations and an Inverse GA/FEM Computational Scheme

by D. S. Liu¹, C. Y. Tsai¹, S. R. Lyu²

1 Department of Mechanical Engineering, National Chung Cheng University, 168, University Rd.,Ming-Hsiung, Chia-Yi, 621, Taiwan, R.O.C.
2 Joint Center, Tzu-Chi General Hospital, Tzu-Chi University, Chia-yi, 621, Taiwan, R.O.C.

Computers, Materials & Continua 2009, 11(2), 147-164. https://doi.org/10.3970/cmc.2009.011.147

Abstract

This study presents a novel numerical method for extracting the tempe -rature-dependent mechanical properties of the gold and aluminum thin-films. In the proposed approach, molecular dynamics (MD) simulations are performed to establish the load-displacement response of the thin substrate nanoindented at temperatures ranging from 300-900 K. A simple but effective procedure involving genetic algorithm (GA) and finite element method (FEM) is implemented to extract the material constants of the gold and aluminum substrates. The material constants are then used to construct the corresponding stress-strain curve, from which the elastic modulus, yield stress and the tangent modulus of the thin film are subsequently derived. Results from high-temperature (900 K) nanoindentation MD simulation show that the value of elastic modulus of the gold and aluminum thin-films could decrease by 63.9% and 73.1%, respectively, as compared with the room temperature values. The resulting temperature-dependent stress-strain curves presented in this paper provide the crucial requirement for quantitative computer simulation of nanofabrication process.

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