Title: Low temperature dependence of mechanical process of ultrathin aluminium films: molecular dynamics simulations

Authors: Qiao-Neng Guo; Jie-Fang Wang; Shi-E. Yang; Mingxing Wang; Xue-Jie Han; Qiang Liu; Dong-Hui Zhu; Liang-Kui Hu

Addresses: School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China ' School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China

Abstract: The mechanical process of aluminium thin films under uniaxial tensile strain was simulated with molecular dynamics method in a low temperature range from 40 to 250 K. The stress-strain curve and potential energy-strain curve of aluminium thin film under uniaxial tensile deformation were obtained. The variation characteristics of stress-strain curves with temperature are alike at the elastic stage. However, at the plastic stage the stress-strain curves are grouped into three categories (40 K ≤ T < 100 K, 100 K ≤ T < 200 K, 200 K ≤ T ≤ 250 K). From the stress-strain curves, we found the strange temperature dependence of the local maximum stress, maximal potential energy and their corresponding strain: when the temperature is below 100 K, they go down quickly with temperature, and when above 100 K and below 200 K, they descend slowly and do very slowly above 200 K. Therefore, we have identified two critical temperatures for the transition of plastic flow mechanism.

Keywords: thin film; tensile properties; temperature effect; molecular dynamics.

DOI: 10.1504/IJNM.2019.097249

International Journal of Nanomanufacturing, 2019 Vol.15 No.1/2, pp.148 - 157

Received: 08 May 2017
Accepted: 26 Oct 2017
Published online: 07 Jan 2019 *

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