Quality analysis and control of tubular wordpiece hot spinning of BT20 titanium alloy

To study the forming quality during tubular workpiece hot spinning of titanium alloy, a hot spinning experiment of BT20 titanium alloy was carried out, and the process of hot powerful spinning was simulated by three dimensional rigid viscoplastic FEM. Moreover, the causes of quality defects (such as crack, pileup, abnormal convex surface) were discussed. The results show that temperature is one of the most important process parameters which influence forming quality of spun components. Whether the temperature is reasonable or not directly determines the spinning quality of titanium alloy. The proper spinning temperature for BT20 titanium alloy is in the range of 600°C-680°C. The feed rate and the reduction percentage are important factors influencing forming precision of hot spinning. To improve the dimension precision of the wall thickness and the tubular workpiece diameter, the thermal expansion of the workpiece, the mandrel and the rollers should be considered while process parameters are selected before hot spinning.