Nanoindentation behavior in T-carbon thin films: a molecular dynamics study

• Main Authors: Zhou, Runhua, Huang, Changjin, Srikanth, Narasimalu, Bai, Lichun, Wu, Mao See
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2025
• Subjects: Engineering; Hardening mechanisms; Molecular dynamics
• Online Access: https://hdl.handle.net/10356/182480
• Institution: Nanyang Technological University

T-carbon is a new allotrope of carbon materials, and it displays high hardness and low density. Nevertheless, the hardening mechanisms of T-carbon thin films under nanoindentation remain elusive. This work utilizes molecular dynamics simulation to explore the hardening mechanisms of T-carbon thin films under nanoindentation with variations of loading velocities and temperatures. The results reveal that a loading velocity increase at a given temperature raises the nanoindentation force. The increase in nanoindentation force is due to graphitization, which is related to the fracture of tetrahedral structures in T-carbon thin films. However, increased graphitization caused by an increased temperature lowers the nanoindentation force at a given loading velocity. The increased graphitization is influenced by both the fractured tetrahedrons and the deformation of inter-tetrahedron bond angles. This is attributed to the loss of thermal stability and the lower density of T-carbon thin films as the temperature increases. These findings have significant implications for the design of nanodevices for specific application requirements.