Abstract:

The calculation of deforming force depends on experience formula in extrusion process design. It may leads to large calculation error and can not be used in optimization design. Based on the classical plasticity theory, a more accurate and convenient calculation model of extrusion force was studied  by mathematical methods. Based on slip line field theory, the backward extrusion process with a cup-shaped mold was studied. Series slip-line field features of different compression ratio were analyzed and superposed. The stress field and deforming force were calculated. The analytical relationship between slip-line field parameters and mold geometrical parameters were analyzed. In  this way, the numerical analysis model of the deformation physical parameters of  geometric parameters was established. The analytical solution obtained  by the numerical analysis model has more obvious physical significance than that  by the slip-line field method. If deformation geometric parameters are   known, the analysis model could  be conveniently used to solve extrusion force. Finally, the extrusion force was also measured with experiments and  combined with experience formula for verification. The results showed  that the numerical analysis model calculation results were  more accurate, which could  be used as an objective function to realize processing optimization design.

Key words: extrusion force, slip-line field, numerical analysis