Experimental and numerical study on the distribution of thickness and dimensional accuracy of AA 6061 in two-point incremental forming using flexible die

Nowadays, in metal forming industries, the production of parts with proper thickness distribution and geometric accuracy is very important and significant. In this research, all parts are formed by a new process called two-point incremental forming process using a flexible die. Flexible die, is a die that consists of a number of separate overhead pins that can be adjusted by the height of each pin according to the desired geometry. First, the effect of the thickness (0.5, 1.5, 3 and 6mm) and hardness (60 and 90Shore A) of rubber layers on the two parameters of thickness distribution and geometric accuracy of the formed samples has been studied. The effect of the arrangement of the pins in a flexible die with full and partial layout on the two mentioned parameters has been studied. The results show that the geometric accuracy of the sample formed on the rubber layer with a thickness of 0.5mm has been improved by 78.3% compared to the thickness of 6mm, but the degree of thickness of this workpiece is more than other parts. Geometric accuracy of the workpiece is also improved by 61.77% when using a rubber layer with a hardness of 90Shore A compared to a hardness of 60Shore A, but the thickness distribution of the workpiece is the same. The pins with full arrangement have a better geometric accuracy and thickness distribution than the partial arrangement in a flexible die. Using a multi-step strategy in a flexible die has the disadvantage of wrinkling.