Significance analysis of process parameters on cross section distortion of high-strength TA18 tube in numerical control bending

Abstract

To achieve the precise numerical control (NC) bending and improve the forming quality of high-strength TA18 titanium alloy tube (TA18-HS tube), the significance of process parameters on cross section distortion in the TA18-HS tube NC bending should be clarified. Taking the TA18-HS tube of 6.35 mm × 0. 4064mm (out diameter × wall thickness) as the objective, a three dimensional (3D) elastic plastic finite element (FE) model based on virtual orthogonal test was used to explore the effects of process parameters on cross section distortion behaviors in the TA18-HS tube NC bending. The results show that the clearance between tube and mandrel Cm, the clearance between tube and bending die Cb, the friction between tube and wiper die fw and the mandrel extension length e are significant factors for cross section distortion in the TA18-HS tube NC bending, and the significant factors on cross section distortion from high to low are the Cb, e, fw and Cm. The cross section distortion degree increases with the increase of the Cb, fw, Cm or with the decrease of the e.