Research On Surface Integrity Of Inconel718 Nickel-based Superalloy Continuous Milling

Nickel-based superalloys have excellent corrosion resistance,high temperature resistance,thermal stability,reliability,etc.,and are widely used in cutting-edge defense fields such as aerospace,nuclear industry,and weapon manufacturing.With the rapid development of the national defense field,the surface quality of nickel-based superalloys is required to be higher,and the surface integrity of milling nickel-based superalloys has become a research hotspot.However,when cutting nickel-based superalloys,there are difficulties such as large cutting force,high cutting temperature and poor quality of the machined surface.Therefore,research on the surface integrity of milling nickel-based superalloys is carried out to improve the level of nickel-based superalloy cutting processing technology.In this paper,the nickel-based superalloy Inconel718 is used as the processing object.Aiming at the problem of poor surface quality,the method of combining simulation and experiment is used to study the milling force,milling temperature and chip shape,as well as residual stress and surface roughness that affect the surface integrity Sexual factors.1)Based on ABAQUS,the milling force and milling temperature were simulated,and the influence of process parameters on the milling force and milling temperature was analyzed by single factor experiment.The orthogonal test method and range analysis are used to obtain the optimal combination parameters,and the milling force prediction model is established.The results show that when the spindle speed n is 4000r/min,the milling depth ap is 0.2mm,and the feed per tooth fz is 0.02mm/z,the milling force is the smallest.The average relative error of the prediction model is 7%,which verifies the reliability of the model.2)Based on the ABAQUS simulation of the residual stress of the machined surface,the influence of the process parameters on the size and distribution of the residual stress of the machined surface was studied by a single factor experiment.The results show that the spindle speed and the feed per tooth have a greater influence on the residual stress,and a higher spindle speed should be selected to obtain a better residual stress.3)Single factor experiment and orthogonal experiment are used to study the influence of process parameters on surface roughness;range analysis is used to determine the degree of influence of process parameters on surface roughness,and a prediction model of surface roughness is established.The results show that the spindle speed n is the biggest influence on the surface roughness,followed by the milling depth ap,and the smallest influence is the feed per tooth fz.When the spindle speed n is 2000r/min,the milling depth ap is 0.2mm,and the feed per tooth fz is 0.03mm/z,the surface roughness is the smallest.The average relative error of the prediction model is 6.5%.The accuracy of the model is verified,and guidance is provided for reducing surface roughness.4)Through single-factor experiments,the influence of spindle speed on chip morphology was studied;the critical moment of saw-tooth chip generation and the characteristics of chip burrs were analyzed,and the morphological changes of chip bottom and surface under different spindle speeds were studied.The results show that: when the spindle speed is 2000r/min,sawtooth chips are generated.With the increase of the spindle speed,the degree of chip sawtooth is gradually serious,and the height and spacing of chip burrs show a trend of first decreasing and then increasing.