Electrically Assisted Stretch Bending of Aluminum Extruded Profile

¹ Metal Forming Department, Beijing Aviation Manufacture Technology Research Institute, 100024 Beijing, China.
² Aeronautical Key Laboratory for Plastic Forming Technologies, 100024 Beijing, China.
³ Beijing Key Laboratory of Digital Plastic Forming Technology and Equipment, 100024 Beijing, China.

^* Corresponding author : herr.liubaosheng@163.com

Abstract

Aluminum extruded profile is widely applied in aircraft frame parts whose forming quality is directly related to the assembly accuracy, aerodynamic shape and the service life of aircraft. However, it normally faces difficulties of large springback and low forming limit while forming at room temperature by stretch bending method. Here, electricity was applied in stretch bending process to heat aluminum profile aiming at improving the formability and reducing the springback by using electrically assisted stretch bending machine which is consisted of electrical power with the capability of 10000A and 40000kN stretching force for each hydraulic cylinder. In this research, a set of uniaxial tension tests was performed at different temperature to determine the relationship between the deformation behavior of aluminum profile and temperature. Then, a series of stretch bending tests were conducted to investigate the springback law of the aluminum profile. The corresponding stretch bending parts were obtained under different conditions. The experiment results show that, the plasticity of aluminum profile can be improved when the temperature rises, and the springback of aluminum profile can be reduced even more due to the electrical heating effect compared to the cold stretch bending process. Therefore, the forming accuracy of aluminum profile can be improved in electrically assisted stretch bending process.