In general, Ti-6Al-4V alloy sheets are formed by press forming in the temperature range between 600 and 900 ℃. In this temperature range, the ductility of Ti-6Al-4V alloy is improved. Because of the low ductility of Ti-6Al-4V alloy at temperatures between room temperature and 600 ℃, fracture easily occurs during press forming. Hence, a method of drawing and ironing Ti-6Al-4V alloy sheets at room temperature was developed. In this method, the punch motion and blank holding force were applied separately to prevent fracture at the punch shoulder. Because of the shear transformation occurred by the motion control, it was confirmed that fracture was prevented at room temperature during drawing and ironing. In addition, by applying the developed method, we were able to prevent the decrease in thickness at the punch shoulder, compared with the case of press forming. As a result, the cold drawing and ironing Ti-6Al-4V alloy sheets at room temperature were achieved by applying the developed method in experiments and finite element analysis.
