Theoretical Study on Influence Factors of the Angle of Inner Hole Generatrix through Cone Hole Open-die Cold Extrusion

The plastic deformation characteristic of cone hole open-die cold extrusion was analyzed based on the concepts of hydrodynamics, the stream function of instantaneous velocity field was built.According to the determination of the equation of stream function, the kinematically admissible continuity unstable velocity field and the shape and position of its relevant velocity discontinuity were built.The factors of velocity field were analyzed.The theoretical model of extrusion power was obtained by the upper bounding theory.The factors of the angle of the cone hole generatrix were analyzed by programming and calculating.