Development of a novel severe plastic deformation method for tubular materials: Tube Channel Pressing (TCP)

A new severe plastic deformation (SPD) method entitled Tube Channel Pressing (TCP) is proposed. In this study, the ability of TCP on strength improvement and grain refinement is assessed. This method is based on pressing a tube through a tubular channel die with a neck zone. Utilization of a mandrel fitted inside the tube prevents the crumpling of tube and preserves its initial dimension. Due to the symmetric design, after one pass, the die is rotated upside down and the second pass is applied by pressing the tube in inverse direction. Ultimate strength of a commercial purity aluminum tube after 5 successful passes is improved to 2 times of the initial strength. Analytical calculations and simulation of this process accompanied by commercial finite element code ABAQUS/Explicit demonstrate that the total average equivalent strain of 1.2 is imposed in each pass. Furthermore, hardness distribution through tube thickness is assessed. Then, ability of TCP in grain refinement of tubular samples after each pass is determined.