A Novel Method for Reducing Springback of Hot Stretch Bending Parts

Abstract

Due to the impact of temperature on springback in hot stretch bending(HSB) process, this paper proposed a modified hot stretch bending(MHSB) process in which a reheating process was added before post stretching. The reheating process was realized by controlling the current distribution in the straight region and the bent region of titanium extrusion. Prior to HSB tests, uniaxial tensile tests were carried out to determine the deformation behavior of extrusion under the temperature condition similar to the HSB processes investigated. The results of the tensile tests provided supporting evidence for that the temperature of post stretching strongly affected the forming accuracy of hot stretch bending parts. Particularly, much more joule heat generated in the bent region than in the straight region successfully reheated it to initial forming temperature by increasing current before post stretching. Accordingly, the springback was significantly reduced via the novel method compared to conventional hot stretch bending(CHSB) process. This method is proved to be an efficient and lower cost solution for reducing springback in HSB.