Effect of Cold Working and Annealing on Springback Behavior in Aluminium Sheet

Abstract

The purpose of this project is to study the effect of cold working and annealing on springbackbehaviors of Al-Mn alloy. The received samples were homogenized at 550 ^oC for 5 hours beforesubsequently cold rolled to 1 mm thickness (50-87 percent of reduction). 87% reduction samples wereannealed in various temperatures in the range of 100 to 600 ^oC, for 30 minutes. The results showed thattensile strength and hardness of the as-rolled samples with 87 % cold work were 244 MPa and 79 HV,respectively. A springback angle was 6.5 degree. After annealing of all conditions, tensile strength andhardness decreased with increasing the annealing temperatures. After annealing at 400 ^oC, tensile strengthand hardness of samples were 139 MPa and 40 HV, respectively, resulting in reduction of springback. Itcould be concluded that the annealing temperature above 400 ^oC could reduce the springback completely.However, it should be beared in mind that the tensile strength of samples normally reduces after annealing.Annealing temperature selection on press forming sheet metal process to reduce springback behavior ofAl-Mn alloy should therefore be compromised which is fruitful to eliminate the mold correction or toreduce cost in a suitable mold making.

Keywords : Springback /Cold Rolling / Bending / Aluminium Alloys/ Annealing.