Analysis Of Residual Stress Based On Dem For Quartz Glass In Micro Milling

Quartz glass is typical of hard and brittle materials,it is widely used in optics,automobile,machinery,biological engineering,aviation and other aspects due to its good physical properties.With the increasing demand of quartz glass,the requirements on surface quality and processing efficiency are constantly improved.The state of residual stress generated by mechanical processing has a direct effect on the quality of the machined surface,and further influence the mechanical properties and fatigue strength of the material.Therefore,it is necessary to investigate the residual stress on the surface of the quartz glass.By means of combining discrete element simulation and experimental analysis,the influence rule of residual stress is studied in this thesis.2D/3D DEM model of quartz glass is established by the program of PFC2d/ PFC3 d.Based on the 2D model,the 2D cutting process was simulated.The influence rule of residual stress with main cutting parameters was studied by single factor analysis.Based on the 3D model,the 3D cutting process was simulated.The influence rule of residual stress and milling forces with main cutting parameters were studied by orthogonal experiment method.Micro milling experiments of quartz glass were completed on the experimental platform.The milling force in different directions was obtained by orthogonal experiment method.By analyzing the simulative and experimental data,the primary and secondary order of the effects of milling parameters on the milling force was obtained.The change trend about milling force of discrete element simulation was consistent with the experimental results,indicating the rationality of using discrete element method to analyze the residual stress.Finally,the influence of milling parameters on the 3D topography and surface roughness of quartz glass were studied by single factor experimental method.Based on this study,a set of convincing optimal milling parameters was obtained for good surface quality and high processing efficiency combined with the milling forces in X,Y and Z directions.