Numerical And Experimental Analysis On High Speed Grinding Inconel718 With Single Grit

High temperature nickel-based alloys play an important role in the field of high temperature resistant materials.High temperature nickel-based alloys are widely used in aviation,turbine and ship due to their excellent strength and stability and excellent performance at high temperature.Due to its poor thermal conductivity and small specific heat capacity,high temperature in the cutting area,serious machining hardening,the blockage and wear of the grinding wheel are easily to be leaded,low machining efficiency and poor machining performance,as titanium alloy is recognized as difficult to process materials,its difficult process limits its development and application.Inconel718 contains a lot of hard point particles,which may lead to tool wear and even failure in the process of machining.In order to solve this problem,superhard material PcBN is used to process hightemperature nickel-based alloy materials.The unique self-sharpening characteristic of PcBN material itself can cause c BN spalling to form a new cutting edge at the same time of wear,which can improve the removal ratio of workpiece material to a certain extent.Due to the randomness of the number,shape and size of abrasive particles involved in the grinding process,the effects of various mechanical and physical phenomena in the grinding process are complex,so it is difficult to study the mechanism of high-speed grinding.In this paper,single abrasive is used to study the grinding force,the morphology of the abrasive marks,the material pile-up ratio and the abrasive wear in the grinding process,which provides theoretical support for the study of the complex grinding process.The main research contents of this paper are as follows:(1)The simplified geometric model of single abrasive is analyzed,and the geometric shape of the abrasive is determined as pyramid;The movement track of abrasive particles and the theoretical formula of grinding force in grinding process are analyzed,the grinding mode of abrasive is determined and the experimental equipment is built.(2)Deform-3D is used to simulate the Inconel718 process of high-speed grinding of single abrasive,and single abrasive simulation model with different grinding speeds and depths is established.The results show that the grinding force decreases with the increase of the cutting speed,and increases with the increase of the grinding depth.The wear area and wear depth of single PcBN grain increases with the increase of grinding depth.The wear depth of single PcBN particle increases with the increase of grinding speed,while the wear area of the particle does not change significantly with the increase of grinding speed.(3)The single PcBN abrasive grind high temperature nickel base alloy Inconel718 experiment platform is built,the MV-40 vertical machining center is used for single high-speed grinding PcBN grits experiment,the Kistler9119AA2 dynamometer is used to measure grinding force in the process of experiment,the3 D profilometer SM-1000 and the depth of field microscope are used for grinding crack morphology and particle morphology of wear data,analysis of grinding crack morphology changes rule for grinding mark cross section and material accumulation ratio,from material stacking and the wear cross section changes the angle of the research and analysis of abrasive wear.The results show that the grinding force decreases with the increase of the linear velocity of the grinding wheel and increases with the increase of the grinding depth.Under the same parameter condition,the grinding force tends to increase with the increase of the cutting times,and decreases in the process of increasing.When the cutting times continue to increase,the grinding force will decrease to a certain extent,and the fluctuation point of the grinding force and the inflection point of the later decline advance with the increase of the cutting depth.When the abrasive wear is passivated,the grinding force ratio increases,and the grinding force ratio begins to decrease after the abrasive grain appears a new cutting edge.With the increase of cutting times,the material accumulation ratio on both sides of the marks increases first and then decreases,and then increases with the increase of cutting speed and grinding depth.At the initial wear stage of abrasive grains,microcracks and cracks appear at the grinding tip;at the stable wear stage,cracks expand along the cutting edge,and large spalling occurs on the surface of abrasive grains to form a new cutting edge.