Study On Interface Mechanical Properties Of Graphene Reinforced Alumina Ceramic Tool Based On Molecular Dynamic

The addition of graphene to ceramic tools has resulted in graphene-reinforced composite ceramic knives with superior mechanical properties to those of pure single-phase ceramic knives.However,due to the limitations of experimental conditions,research on graphene-reinforced composite ceramic tools has been limited to optical microscopy and macroscopic properties,while research on the mechanical properties of the interface between the ceramic matrix and graphene in graphene-reinforced composite ceramic tools is relatively rare.In this thesis,the process of graphene pulling out alumina ceramic tool matrix was simulated by using molecular dynamics simulation method by selecting appropriate force field,ensemble and boundary conditions.The effects of graphene pull-out speed,system temperature,vacancy defect,graphene fold and the type of ceramic tool matrix on the mechanical properties of nanocomposite ceramic tool interface were studied,and the microscopic principles of the mechanical properties of composite ceramic tool interface changes during the pull-out of graphene were revealed,which provided some ideas for further research on the interface properties of graphene reinforced composite ceramic tools.At the same time,it provides a theoretical basis for the development and preparation of new graphene reinforced composite ceramic tool.The effects of graphene pull-out speed,system temperature and graphene vacancy defects on the mechanical properties of the tool interface of Al₂O₃/GR nanocomposite ceramics were investigated.The results show that the interface interaction energy（639.91e V）and the interface shear stress（382 MPa）between the tool interfaces of Al₂O₃/GR nanocomposite ceramics are large.The maximum interface pulping force and shear stress of graphene increase with the pulping speed.The interfacial interaction energy,maximum interfacial shear stress and pull-out force of Al₂O₃/GR nanocomposite ceramic tool decrease with the increase of temperature,and creep occurs in alumina ceramic tool matrix with the increase of temperature.The maximum interfacial pull-out force and shear stress of Al₂O₃/GR nanocomposite ceramic tool were increased by proper vacancy defects in graphene.The effects of graphene folds,ceramic tool substrate type and pull-out speed on the interfacial mechanical properties of nanocomposite ceramic tools were investigated.The results show that pleated graphene can enhance the interfacial mechanical properties of alumina nanocomposite ceramic tools more effectively compared to flat graphene.The interfacial mechanical properties of Al₂O₃/GS nanocomposite ceramic tools were better compared with those of Si C/GS nanocomposite ceramic tools.the maximum interfacial pull-out force of both Al₂O₃/GS and Si C/GS nanocomposite ceramic tools increased with the increase of graphene pull-out speed,and the maximum interfacial pull-out force of Al₂O₃/GS nanocomposite ceramic tools at different speeds was still much higher than that of Si C/GS nanocomposite ceramic tools.The maximum interfacial pull-out force of Al₂O₃/GS nanocomposite ceramic tools at different speeds was still much higher than that of Si C/GS nanocomposite ceramic tools.Finally,the Al₂O₃/GR nanocomposite ceramic tool material was experimentally prepared and the graphene pull-out simulation was verified by fracture morphology seeing the graphene pull-out,fracture and graphene folds.