Deep drawability of commercial purity aluminum sheets processed by groove pressing

摘要

Formability of aluminum alloys poses a major challenge for their wider application in automotive sheet metal components as the deep drawability of aluminum is low when compared to steel. This is indicated by the low limiting drawability ratio (LDR) of aluminum sheet blanks which is characterized by the poor r value or the plastic strain ratio. Recently, a number of techniques have been attempted to improve the r value of an FCC metal like aluminum by altering the texture. In the present study, a groove pressing process was carried out on commercial purity aluminum sheets under three different orientations to its rolling direction. The r, r_m and Δr values of the groove pressed specimens were experimentally determined. Improvements in these values were obtained. X-ray diffraction scans were carried out on the specimens to measure the relative intensities of the (111) and (200) peaks in the pattern. The LDR, determined by the Swift cup forming test shows an improvement for the aluminum sheet specimen groove pressed at 0° and 45° to the RD. This can be attributed to the improved r value due to the development of (111)//ND shear texture imparted to the specimen by groove pressing.