Comparison of radial forging between the two- and three-split dies of a thin-walled copper tube during tube sinking

Abstract

This study presents a finite element (FE) analysis of the tube sinking of a thin-walled copper tube through a radial forging process (RFP) with two- and three-split dies without mandrel. Three-dimensional FE models of two-split dies RFP and three-split dies RFP are established. The effects of die number on the formation characteristics of the thin-walled copper tube through RFP are studied. Results show that the strain of the thin-walled copper tube through three-split dies RFP distributes more uniformly than that through two-split dies RFP under the same conditions. Defects such as wrinkles and wings more easily emerge at the surface of the thin-walled copper tube through two-split dies RFP than three-split dies RFP. The feeding and forging loads are investigated using FE method. The loads in two-split dies RFP are greater than those in three-split dies RFP. Experiments are conducted to verify the simulation results, and good agreement between the two sets of results is found. The relationship between the error of the hammer strike frequency and the rotational speed of the spindle is derived. The experiments indicate that the slippage in the radial forging machine is important for the service life of the machine and is thus investigated. Moreover, the loudness of the noises in the radial forging machine is also measured.