Stagnation points and theoretical modeling of dead metal zone in extrusion machining with chamfered tool

To investigate the mechanism of extrusion machining with chamfered tool (CT-EM) and establish the prediction models, experiments and numerical simulations were performed. By varying the chamfer angles ( γ 2 ) and widths ( w c ), the mechanical properties and microstructure of prepared strips were thoroughly studied. The results revealed that γ 2 affected the gravity center of dead metal zone (DMZ) and the relative position of stagnation points, while w c mainly affected the DMZ area. Lower γ 2 and higher w c increased effective strain and cutting temperature in DMZ, improving strip hardness and tensile strength. Furthermore, the predictive models of cutting force and deformed layer thickness matched experimental results. This study enriches the theory and modeling of CT-EM, further expanding the application of chamfered tools.