A molecular-dynamics study of the tensile deformation and fracture behavior of nanostructured lithium aluminum oxide

College of Optoelectronic Technology, Chengdu University of Information Technology - Chengdu 610225, China

^(a) yy2012@cuit.edu.cn (corresponding author)

Received: 30 September 2017
Accepted: 30 January 2018

Abstract

Three-dimensional nanocrystalline models of LiAlO₂ with the log-normal grain size distribution are constructed with constrained Voronoi tessellation. First, the relaxation procedure of nanostructured LiAlO₂ is carried out using molecular dynamics. The results suggest a reduction in the atomic densities after the relaxation process. Next, the tensile deformation and fracture behavior of nanostructured LiAlO₂ are studied by using the optimized model. By researching the tensile deformation and fracture behavior of nanostructured LiAlO₂, we find some interesting results: on the one hand, the greater the average grain size of the sample is, the stronger its tensile strength. On the other hand, after the strain reaches approximately 3% of the deformation of the sample, the stress of the sample does not change with the increase of the strain, displaying a plastic flow of the plastic material.