Molecular Dynamics Study of the Deformation Behavior and Strengthening Mechanisms of Cu/Graphene Composites under Nanoindentation
Guangan Ren,
Cong Zhou,
Yongle Hu,
Li Wang,
Jingzhong Fang,
Yejun Li,
Yi Wang,
Jian Liu,
Mingjun Zhang,
Yonggang Tong
Affiliations
Guangan Ren
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
Cong Zhou
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
Yongle Hu
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
Li Wang
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
Jingzhong Fang
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
Yejun Li
Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha 410083, China
Yi Wang
Science and Technology on Ballistic Missile Penetration Laboratory, Beijing 100076, China
Jian Liu
National Engineering Research Center for Mechanical Product Remanufacturing, Army Academy of Armored Forces, Beijing 100072, China
Mingjun Zhang
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
Yonggang Tong
College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha 410114, China
The mechanical performance of pure copper can be significantly strengthened by adding graphene without greatly sacrificing its electrical and thermal conductivity. However, it is difficult to observe the deformation behavior of Cu/graphene composites efficiently and optically using experiments due to the extremely small graphene size. Herein, Cu/graphene composites with different graphene positions and layers were built to investigate the effect of these factors on the mechanical performance of the composites and the deformation mechanisms using molecular dynamics simulations. The results showed that the maximum indentation force and hardness of the composites decreased significantly with an increase in the distance from graphene to the indentation surface. Graphene strengthened the mechanical properties of Cu/graphene composites by hindering the slip of dislocations. As the graphene layers increased, the strengthening effect became more pronounced. With more graphene layers, dislocations within the Cu matrix were required to overcome higher stress to be released towards the surface; thus, they had to store enough energy to allow more crystalline surfaces to slip, resulting in more dislocations being generated.
