Wear Mechanisms And Regulations Of The Punch For Driver Plate Fine Blanking

Fine blanking is a high precision processing technology,which is widely used in various fields of automobile manufacturing,aerospace and electronics manufacturing,etc.But the die wear problems have restricted the development of fine blanking production.Frequently repairing mould during production process not only directly improves the production costs,lowers productivity,but also affects the quality and dimensional accuracy of the workpiece in fine blanking.In response to these problems and on the basis of the wear characterization and mechanism analysis,experiments and finite element simulation method are used to explore the convex wear factors and wear regularity for driver plate fine blanking.A series of tests is carried out for cold work die steel ASSAB88,improved pin-on-disk test closer to the fine blanking working conditions is independently designed,and the basic mechanical properties of wear resistance of ASSAB88 are acquired.Wear analysis and wear mechanism exploration are given to the punch,which endured wear failure,in the fine blanking of the driver plate.It is discovered that the process of the abrasion for the punch in the driver plate is a complex failure process,with three different wear mechanisms,including adhesive wear,abrasive wear and fatigue wear,amongst which mutual influence and promotion displace,and that microcracks generate and expand during the process.Finite element model is established based on fine blanking process of the driver plate.With suitable ductile fracture criterion selected,metal forming characteristics and shear cutting surface quality in the process of the driver plate fine blanking are analyzed by simulation,combined with flow stress curves and the fracture parameters,which are acquired through the mechanical tests,and verified by tests.The process of the wear evolution for the punch in the driver plate fine blanking is analyzed using the finite element method and research on wear factors and the quantification of die wear are used to explore the regularity between wear and process parameters,such as blank holder force,ejector force,punching speed,blanking clearance,punch hardness,die bevel angle.