Molecular dynamics simulation of crack propagation in very small grain size nanocopper with different grain size gradients

Fankai Xian; Jinjie Zhou; Xiaofeng Lian; Jinchuan Shen; Yuepeng Chen

doi:10.1039/d3ra07374b

Molecular dynamics simulation of crack propagation in very small grain size nanocopper with different grain size gradients

RSC Adv. 2024 Jan 2;14(1):616-625. doi: 10.1039/d3ra07374b.

Authors

Fankai Xian^{1

2}, Jinjie Zhou^{1

3}, Xiaofeng Lian², Jinchuan Shen^{1

3}, Yuepeng Chen^{1

2}

Affiliations

¹ School of Mechanical Engineering, North University of China Taiyuan 030051 P. R. China zhoujinjiechina@nuc.edu.cn.
² The Key Laboratory of Industrial Internet and Big Data, China National Light Industry Beijing 100048 P. R. China.
³ Shanxi Key Laboratory of Intelligent Equipment Technology in Harsh Environment, North University of China Taiyuan 030051 China.

Abstract

In this paper, we use molecular dynamics to simulate the crack propagation behavior of gradient nano-grained (GNG) copper models with different grain size gradients, compare the crack propagation rates of different models, and analyze the microstructural changes and the mechanism of crack propagation. The simulation results show that the increase of the grain size gradient of the GNG copper model can improve the fracture resistance of the material, and the crack propagation mode undergoes a transition from brittle propagation along the grain boundaries to the formation of pores at the grain boundaries, and then to ductile fracture along the inclined plastic shear zone. The number of dislocations increases with the grain size gradient, while the crack passivation is more serious, indicating that a larger grain size gradient is more effective in inhibiting crack propagation. The introduction of gradient grain size promotes crack propagation and weakens the plasticity of the material relative to the nano-grained (NG) copper model.