Effects of graphene pull-out on the interfacial mechanical properties of alumina/graphene nanocomposite ceramic tool materials: Molecular dynamics analysis and material preparation

The interfacial mechanical properties of the alumina/graphene (Al2O3/GR) nanocomposite ceramic tool materials were studied by molecular dynamic simulations. The effects of pull-out velocity of graphene, system temperature, vacancy defect, and wrinkled graphene on the interfacial mechanical properties were investigated. Results show that a large interfacial shear stress (382 MPa) exists between the Al2O3/GR interface. The maximum pull-out force and interfacial shear stress increase with increasing graphene pull-out velocity. The increase of temperature reduces the maximum pull-out force and interfacial shear stress. Moreover, the load transfer capacity is reduced and the creep of the matrix occurs. These factors reduce the fracture toughness of the Al2O3/GR nanocomposites. A moderate amount of vacancy defects in graphene increases the interfacial pull-out force and shear stress of Al2O3/GR nanocomposite ceramic tool. Compared with Al2O3/GR nanocomposite ceramic tools, the interfacial interaction energy and shear stress of pleated graphene and Al2O3 were increased by 13.87% and 41.08% respectively, with better toughening and reinforcement. The results are of significance in further understanding of the interfacial mechanical properties at the nanoscale and then beneficial to improve the mechanical properties and engineering performance of Al2O3/GR composite ceramic materials. image