Study On Tool Wear And Interface Behavior Of Ceramic Tool Cutting Nickel-based Alloy

Nickel-based superalloy GH4169 can maintain good physical and mechanical properties at 650?-1000?,so it is widely used in the manufacture of turbine disks and blades of aeroengines.However,the nickel-based superalloy has the characteristics of large plastic deformation and low thermal conductivity in the machining process,which makes it easy to have high cutting area temperature and large fluctuation of cutting force in the cutting process,which leads to the tool is easy to wear during the cutting process and affects the processing quality.Therefore,it is of great significance to study the tool wear mechanism in the cutting process of nickel-based alloy to improve the machining quality.The machining process of nickel-based superalloys is usually completed by precision or ultra-precision cutting.Therefore,by means of molecular dynamics simulation,this paper studied the tool bonding,diffusion wear and interface behavior of nickel base superalloy from the atomic scale.According to the macroscopic characteristics and microscopic crystallographic structure of cutting tool and working material,the polycrystalline cutting model of nickel base alloy cut by silicon carbide toughened alumina ceramic cutting tool was established,and the material properties of the model were verified.The potential function between the atoms of the tool and the workpiece,and between the matrix inside the tool and the toughening is calculated.Through the visual analysis of the simulation results,it is found that the process of adhesive wear is divided into three stages:contact,adhesion and shedding.From stress,radial distribution function,can form three aspects analyze the caking phenomenon in the process of cutting and dung and found that binding occurs in knife-workers squeezed the strong point,at the same time cutting tool surface bonding of workpiece atoms and tool atoms formed nickel silicon compounds,a new generation of nickel and silicon compounds reduce the performance of the cutting tool.The atomic displacement,the atomic coordination number of the cutter and the atomic order of the nickel base alloy during cutting are analyzed.Atoms diffusion process begins with the increase of kinetic energy,into space in the workpiece and tool,and calculate the atomic vacancy formation energy and vacancy migration can,when the kinetic energy of the atoms are overcome with enough a space kinetic energy barrier between the atoms to spreading activation can occur when diffusion,through calculation and analysis it is concluded that the spread of the order:Cu>Co>Cr>Fe>Ni.Through macro cutting experiment tool surface morphology under SEM,found in the process of cutting tool Al₂O₃/SiC interface fracture happens,the macro mechanical properties of the material depends on its microstructure,therefore,established Al₂O₃/SiC3d interface model,and calculate the single-phase Al₂O₃,single-phase SiC,complex phase Al₂O₃/SiC interface binding energy of a single interface.Results show that compared with single phase interface,the complex phase Al₂O₃/SiC interface bonding strength is higher,SiC toughening can enhance the toughness and strength of the cutting tool,cutting tool substrate after the diffusion and toughening is formed between the interface binding energy calculation,found that the diffusion reduces the interface bonding strength of cutting tools,cutting tool in Al₂O₃/SiC interface fracture.