High strain rate superplastic forming into rectanglar part of SiC particle reinforced 2124 aluminum alloy composite sheet

Abstract

The forming test was performed at 773 K using a 250 mm × 250 mm blank sheet by the gas pressure, which was preset to achieve the average strain rate of 0.1/s. The rectanglar part is successfully formed with in about 10 seconds and the maximum thickness reduction strain is over 100% at the corner of the part. The high forming rate leads to the uniform thickness distributions of the formed part and it coincides with the bulge forming test conducted by authors in the previous work. From the results of measuring the change in contour shape and thickness distributions, the forming process is proved as follows. The sheet is bulged freely in the die at first and then attaches the bottom or side wall, finally formed along the corner of the die. The process coincides with the shape predicted in the calculation of the gas pressure pattern.