Study Of Optimization Of High Speed Cutting Parameters For Nickel-based Superalloys

High-speed cutting technology has become one of the important research project in the 21 st century,as an advanced manufacturing technology compared with traditional methods,because of its unique processing characteristics and potential application value.High-speed machining of metal materials usually produces saw-tooth chips.The formation of zigzag chips almost affects the entire cutting process,whichincludes cutting temperature,cutting force,surface quality,and the like.It is necessary to study the relationship between the formation of saw-tooth chips and cutting process parameters during high-speed cutting.Chip formation and cutting forces are an important part of the cutting mechanism.Superalloys is one of the typical high-temperature alloy materials widely used in the aerospace field.Due to some factors,such as the high friction coefficient,low thermal conductivity and quench hardening of high-temperature alloys,which serionsly affected the cutting force,cutting temperature and tool wear.All these factors affect the machining efficiency and processing quality of the alloy.In this paper,the nickel-based superalloy GH4169 has been studied,especially the high-speed milling processing performance with in-depth study.According to the experimental results,the high-speed milling process parameters are optimized.The main research work of this thesis is as follows:(1)By analyzing the high-speed cutting deformation mechanism,it is found that serrated chips are prone to occur during high-speed cutting.According to the adiabatic shear theory,the shear-slip cutting model and the cutting equation are concentrated.(2)By finite element software ABAQUS to create a simplified 2D orthogonal cutting finite element model,simulation of high speed cutting chip formation process,the processing cutting tool rake Angle,cutting speed,the adjustment of cutting thickness,discusses on the influence law of chip morphology.(3)Analysis of effects of different cutting parameters on cutting force by finite element transient simulation.From the simulation results,it can be seen that the cutting force decreases with the increase of the tool rake angle and decreases with the increase of the cutting speed and the reduction of the cutting thickness.The two have reached a good agreement,providing the actual production theoretical support.(4)Orthogonal experiment table was designed,experimental data of cutting force under different cutting amounts were measured by orthogonal experiment,data processing was performed by numerical calculation method,and visual comparison was made with data of finite element analysis using graphs,and finite element simulation was conducted.The results are basically consistent with the experimental data.(5)Design of chip shape test for high speed cutting nickel-base superalloy.Keep other parameters unchanged,only change the cutting speed.In the experiment,collect the chips of each set of experimental data and scan through the ZIESS-LSM700 electron microscope to analyze the chip shape at different cutting speeds.It was found that nickel-based superalloys have both band-like and zig-zag chip shapes with a critical cutting speed(60m/min)between them.When the cutting speed is greater than this value,zigzag chips are formed due to the concentrated shear slip.(6)Designing experiments to measure tool wear patterns and tool life during high-speed cutting.It was found that the tool wear during high-speed cutting of nickel-based superalloys was mainly cohesive wear,chipping,and chipping.Measured cutting parameters are worthy of tool life.The results show that the depth of cut has the greatest effect on the service life of the tool.(7)Optimization of high-speed milling parameters for nickel-base superalloys.Based on the goal of minimizing processing costs and maximizing productivity,a multi-objective parameter optimization model based on the constraints of workpieces,machine tools,tools,and machining requirements was established.Using MATLAB genetic algorithm toolbox and graphical user interface toolkit(GUI)to optimize parameters under given conditions.