Effect of anisotropy in commercial parity titanium on deep drawability at elevated temperatures

Commercial purity Ti sheets (0.88 mm thick) were deep drawn by a complex wo rking process at two temperatures using a hot die and a cool punch. The wor king temperature ranged from 25 to 400 degrees C. Generally, the limiting d rawing ratios (LDRs) along both the rolling direction (RD) and transverse d irection (TD) increased with increasing operating temperature, while the op timal blank holding force decreased with temperature. The LDR(RD) is larger than the LDR(TD) at all temperatures in the range tested and the differenc e (Delta LDR) is largest at 200 degrees C or higher, The deep drawn cups fa iled at the cup wall near the die throat along the TD. The thickness strain along the TD was consistently smaller than that along the RD. The anisotro py index delta(01 (1) over bar 1) increased significantly at 100 degrees C and the largest delta(hkil) values were found in delta(0002) along the RD a nd delta(11 (2) over bar 0) along the TD. The reorientation bands that appe ared when drawn at 25 degrees C are a result of work hardening, but the mic roshear bands that occurred in the 400 degrees C specimen are a result of l arge deformation. The difference in microstructures along the TD and RD may explain the anisotropy in deep drawing properties. MST/4401.