An investigation into the effect of strain hardening on the central bursting defects in rod extrusion process

作者：Haghighat Heshmatollah; Parghazeh Amir^*

来源：International Journal of Advanced Manufacturing Technology, 2017, 93(1-4): 1127-1137.

DOI：10.1007/s00170-017-0577-6

• Central bursting defects
• Rod extrusion
• Strain hardening
• Upper-bound analysis

In this paper, an upper-bound analysis is developed to model the rod extrusion process of the strain hardening materials. A velocity field, including radial and angular velocity components, is assumed in the deformation zone. This field permits to predict the possible formation of a central burst. The strain rate levels were calculated in each region of billet to apply strain hardening effect in the presented central bursting criterion. The presented criterion is compared with FEM simulation data and the experimental data of the published papers. The results show that the central bursting defects are affected primarily by the strain hardening exponent. So that by increasing the strain hardening exponent, the possibility of the central bursting defects and the relative extrusion pressure is being decreased. Based on the obtained criterion, the diagram is presented for the safe zones in a wide range of process variables.

• 出版日期2017-10