Study On Creep Feed Grinding Surface Quality Of Narrow Deep Grooves Using Electroplated Grinding Wheel With Orderly-micro-grooves

The special structure of narrow deep grooves with groove width less than 4 mm and ratio of depth to width greater than 2 is more and more widely used in the fields of aerospace,automobile industry and construction machinery,for example aero-turbine engine tongue-and-groove,spline shaft,variable pump rotor groove,etc.Due to the narrow deep groove structure directly affects the reliability,performance and service life of the parts,dimensional accuracy and surface quality requirements of narrow deep groove are very high,which has always been a difficult problem in the field of machining.In particular,the narrow deep groove grinding of hard-to-machine materials such as hardened steel,superalloy,and titanium alloy is prone to defects such as blockage of the grinding wheel,thermal damage of the workpiece,and large surface roughness of the workpiece,which restricts the high-precision machining of such structural parts.Therefore,based on an electroplated grinding wheel with orderly-micro-grooves proposed by the research group,this paper carries out a comparative experiment of creep feed grinding of narrow deep grooves between electroplated grinding wheels with orderly-micro-grooves and ordinary electroplated grinding wheels.And the effects of parameters such as grinding wheel type,cutting depth and workpiece speed on the grinding force and surface quality of creep feed grinding of narrow deep grooves were investigated.The main research contents are as follows:(1)The influence of different parameters on the grinding force was studied.The experimental results show that the grinding force of both the grinding wheel with orderly-micro-grooves and the ordinary grinding wheel increases with the increase of the cutting depth and workpiece speed.When the cutting depth and workpiece speed are small,the grinding force of the grinding wheel with orderly-micro-grooves is smaller than that of the ordinary grinding wheel,and when the cutting depth and the workpiece speed are large,the grinding force of the grinding wheel with orderly-micro-grooves is greater than that of the ordinary grinding wheel.(2)The effects of different parameters on the surface topography,surface profile and surface roughness of the narrow deep grooves after grinding were studied.The experimental results show that the material is mainly removed by plasticity,the grinding textures are deep in the bottom surface of narrow deep grooves,and the grinding textures are shallow in the side surface of narrow deep grooves.With the increase of cutting depth and workpiece speed,the fluctuation of the bottom and side profiles of narrow deep grooves by grinding with the two types of grinding wheels increases;and the fluctuation frequency of the bottom profile is much smaller than that of the side profile.Compared with the ordinary grinding wheel,the bottom surface roughness of narrow deep grooves ground using the grinding wheel with orderly-micro-grooves is slightly increased;but there is little difference in the side surface roughness of the narrow deep grooves ground by the grinding wheel with orderly-micro-grooves and the ordinary grinding wheel.(3)The variation laws of surface/subsurface damage,white layer thickness and microhardness of narrow deep grooves after grinding were studied.The experimental results show that compared with ordinary grinding wheels,the use of the grinding wheel with orderly-micro-grooves can suppress defects such as burns and material adhesion on the surface of narrow deep grooves.The organization of the cross section of the grinding subsurface is composed of white layer,dark layer and bulk material from top to bottom.The hardness of the white layer is higher than that of the bulk material,and the hardness of the dark layer is lower than that of the bulk material.The thickness of white layer of narrow deep groove by using grinding wheel with orderly-micro-grooves is smaller than that of narrow deep groove by using ordinary grinding wheel,and with the increase of cutting depth and workpiece speed,the thickness of white layer of narrow deep groove is increased.And the microhardness of the grinding subsurface of narrow deep grooves by the grinding wheel with orderly-micro-grooves can be reduced.