Characteristics of drawing process of AA5182 aluminum alloy sheet during rubber-pad forming

This paper presents experimental studies of rubber-pad forming process of AA5182 aluminum alloy sheet. The influences of load velocity and rubber pad height for characteristic of polyurethane rubber are investigated firstly by compression tests. It can be concluded that the load force increases quickly with decreasing of rubber pad height. The expansion diameter of polyurethane rubber is insensitive to load velocity at 40 and 60 mm height. Then the deformation characteristic of rubber-pad forming, states of strain, and stress is analyzed to compare with conventional drawing. Furthermore, AA5182 aluminum alloy sheets with thickness of 0.8 and formed target part with diameter of 80 mm and height of 15 mm are investigated under different load velocity varying from 50 to 500 mm/min. The load velocity, load force, and distribution of thickness are analyzed in detail. Results show that the maximum thickness reduction occurs at the bottom corner of the formed part. And the maximum thinning decreases to 20.0% for v = 50 mm/min, 20.0% for v = 100 mm/min, 17.5% for v = 300 mm/min, and 17.5% for v = 500 mm/min. At last, the forming process for target part with diameter of 80 mm and height of 20 mm is also investigated under different load velocity. The results confirmed that it is difficult to form the desired shape.