Comparison of barreling in unlubricated truncated cone billets during cold upset forging of various metals

Abstract

Experiments have been carried out to generate data on cold upset forging of unlubricated annealed commercially pure aluminium, copper and zinc solids of truncated cone billets. The measured curvatures of the barreled truncated cone billets of all the three metals are found to closely conform to the calculated values on the assumptions that the shape of the barrels is in the form of a circular arc. It is further found that the measured radius of curvature of barrels exhibited a linear relationship with a geometrical shape factor irrespective of the aspect ratios of the truncated cone billets. Further, an empirical relationship has been established between the measured radius of curvature of the barrels and stress ratio parameter. A comparative study of barreling behaviour of aluminium, copper and zinc, during upset forging operation in unlubricated condition is presented in this paper.