Study On Grinding Surface Roughness Of Hard And Brittle Materials In Ultrasonic Vibration Assisted Micro End Grinding

In recent years,the hard and brittle materials have been received widespread attention,due to its high hardness,good wear resistance,high temperature resistant,strong corrosion resistance,and a series of excellent physical and mechanical properties.However,these excellent performances also put forward new challenge to the machining process.A large number of scholars study found that ultrasonic vibration assisted micro end grinding has unique advantages in machining hard and brittle materials,it can significantly reduce the grinding force and grinding temperature,inhibition of grinding wheel wear and improve the processing surface quality,etc.The surface roughness of the workpiece is an important parameter of reflecting the processing quality,which is the key point of the research problem.Therefore,this article is based on ultrasonic vibration assisted micro end grinding-UAMEG and to study the grinding surface roughness of hard and brittle materials which has important theoretical and application value.The main research content is as follows:Firstly,the workpiece material removal mechanism of conventional grinding condition is analyzed,and introduces the typical model of the indentation fracture mechanics.Based on the typical indentation fracture mechanics model,the hard and brittle materials removal mechanism of ultrasonic vibration assisted micro end grinding is analyzed.Based on the trajectory equation of two adjacent grains,the kinematics model of ultrasonic vibration assisted micro end grinding is built.Secondly,based on the surface formation principle of ultrasonic vibration assisted micro end grinding,the model of workpiece surface roughness is built.Based on Rayleigh probability density function,a new analytical surface roughness model is developed considering the influence of random distribution of abrasives,grinding conditions,ultrasonic vibration and grain geometric shape which shows the relationship between the surface roughness and the expected value of chip thickness.At last,to verify the correctness of the analytical model and the influence of ultrasonic vibration on grinding surface roughness,the experimental platform of UAMEG is designed.The quartz glass workpiece surface roughness is measured by 3D non-contact surface profilometer of American NANOVEA company.The results show that: through introducing ultrasonic vibration,the grinding surface roughness is significantly reduced under different grinding parameters.The experimental measured surface roughness is consistent with the predicted results of analytical model,but it also produce a certain error.Then,the resulting error is analyzed in detail.