Annealing Effect for Cold Rolling 6016 Aluminum Alloy Sheet

In aluminum alloy sheet metal forming process, annealing treatment can improve the mechanical properties. The tensile test for different temperatures of 400°C, 450°C, 500°C, 550°C respectively have been carried out from 1h to 12h.The result revealed that the ductility increased with the increase of annealing temperature. It is found that the annealing treatment at 500°C for 6 h can get a good property. Furthermore, the result of tensile test showed that the yield strength increased from 130MPa before cold rolling to 190MPa after annealed, and the elongation of the sheet increased to 28.6%. The result of stamping test verified that the limiting draw ratio (LDR) increased after annealing treatment from 1.15 to 1.56. The value of blank holder force for the cylindrical cup is becoming smaller after the annealing treatment. The microstructure investigations on experimental aluminum alloys after long-time annealing and cold rolling conditions were presented. The changes of the main structural contituents have been obviously observed, which improved the formability of the alloys.