Numberical Analysis And Experimental Research On Cutting Process Of Ti6Al4V With Rounded Edge Tool

The round edge of cutting tool can effectively reduce the tool wear and improve the service performance of the insert,which is significant for improving the cutting process of hard-to-machine material.Therefore,this paper starts from the research of rounded edge tool and the cutting process with Ti-6Al-4V is explored.Specifically,the cutting experiment platform and finite element simulation model are both built firstly.Besides,the tool-workpiece contact model is established by exploring the complex material flow and material separation affected by round edge.On this basis,the mechanical and thermal loads in the cutting process are studied,and the surface residual stress and chip formation are also explored.Finally,the influence of edge geometry and cutting parameters on the above research contents are obtained.The research contents mainly include the following parts:The finite element simulation model and cutting experiment platform are built.A two-dimensional cutting simulation model is established in ABAQUS software,which mainly includes material property,contact model,geometric model and boundary conditions.Two different simulation methods were selected for this study:an arbitrary Lagrangian-Eulerian(ALE)method and Coupled Eulerian-Lagrangian(CEL)Method.The experimental platform includes three parts: experimental preparation,orthogonal cutting experiment and testing experiment.The contact mechanism model based on material separation is established.By analyzing the ploughing effect of the rounded edge on workpiece material,the flow behavior of the material around the cutting edge is obtained,and the material separation model is further clarified.On this basis,combined with Coulomb’s friction law,a contact feature point model is proposed.Besides,the normal contact stress is described by a parabolic equation.The shear contact stress model is finally obtained by synthesizing the contact feature point model and the normal stress model.Based on the contact stress model,the contact force model is established,and then the cutting force model is obtained.The contact model variables are selected properly through the optimization algorithm using the cutting forces from the experiment.Then,the cutting force values affected by round edge and cutting parameters are obtained.The cutting temperature is analyzed through the simulation model and the proposed contact model is used in cutting simulation model to make the analysis more accurate.The influence of edge geometry and cutting parameters on cutting temperature is analyzed through a large number of simulations.The research results show that increasing the round edge radius can decrease the surface temperature of the insert and the heat concentration can also be reduced by enlarging the edge radius,which helps to improve the tool life.The chip morphology and residual stresses are explored.On the one hand,the chips obtained in cutting tests are sampled and polished to get the morphology under different variables using the microscope.On the other hand,two methods,including CEL and ALE,are used to achieve the chip formation by finite element simulation.By comparing results with experimental results,it is found that the chips obtained by the CEL method are more accurate.The two-dimensional cutting model will be optimized by the comparison of chip morphology.Through CEL simulation,the residual stress curves under various variables are also obtained.It is found that enlarging the round edge radius can increase the residual stress.