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

摘要

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