Further Analysis of Axisymmetric Upsetting

Abstract

Analytical modeling of deformation processing methods requires a thorough understanding of the die–billet interfacial conditions, in particular, the nature of frictional boundary conditions. In order to gain insight into the role of friction on the deformation behavior of metals under uniaxial compression, a series of carefully controlled experiments were made with 6061-T6 aluminum cylinder and ring specimens. From measurements of the change in internal diameter and the height of the ring specimens, the average friction coefficient can be found using the calibration method proposed by Male and Cockcroft. Using this friction coefficient, a series of finite element analyses were made to model the deformation of solid aluminum cylinders which were compressed under identical die–billet contact conditions. An updated Lagrangian formulation and the contact surface algorithm of the ADINA finite element code were used in the analysis. Comparison of the experimental findings with those of the finite element analysis shows some discrepancies; possible causes for these differences are identified.