Optimization of die design parameters and experimental validation on twist channel angular pressing process of AA6061-T6 aluminium alloy

Twist Channel Angular Pressing (TCAP) is a type of severe plastic deformation (SPD) process which was developed to overcome the drawbacks of Twist extrusion (TE) and Equal channel angular pressing (ECAP) process. This article focuses on identifying the optimum TCAP die geometries for minimum punch load that will yield respectable imposed strain using finite element analysis (FEA). Nine TCAP dies were designed by varying twist slope angle (β) at 35°,45° and 55° and bend channel angle (ψ) at 90°,100° and 110°. DEFORM 3D software is used to analyse the strain distribution and punch load. Based on the FEA results among all the combinations, it is found that the die with twist slope angle of 45° and channel angle of 110° gives good strain rate with lesser punch load. The results are experimentally validated with TCAP of AA6061-T6 at room temperature and its results are in good agreement with the FEA. Moreover, the samples were extruded at room temperature, 150 °C and 250 °C. The effect of temperature on the mechanical properties such as hardness and tensile strength of the processed aluminium alloy were explored and it is observed that sample processed at room temperature exhibit better mechanical properties. (paper)