Electric Hot Single Point Incremental Forming Process of Ti6Al4V Alloy Sheet with Water-Cooled Forming Tool

Electric hot-assisted incremental forming is an effective technique to improve the formability of Ti6Al4V titanium alloy sheets. However, the unstable electric heat can also lead to the unacceptable accuracy and inhomogeneous microstructure. In this study, a water-cooled tool was employed to stable electric-assisted forming temperature. The research results show that the stable forming temperature can significantly improve the forming properties and maintain the consistent microstructure of Ti6Al4V sheets, and the forming force and the degree of springback for the parts also decrease with the increasing temperature. The maximum forming depth is 7.0 mm at 400 degrees C (forming tool temperature) compared with the forming height of 4.6 mm at room temperature. The microstructure results show that the alpha phase is refined, and the beta phase grains are elongated. The fracture morphologies of the parts at room temperature, 300 degrees C and 400 degrees C were compared and analyzed, and the dimples increased in the size and denser at high temperature.