TA18 titanium alloy pipes are widely used in aerospace. Most titanium alloy pipes are bent and formed using CNC bending. This article focuses on the analysis of the bending performance of TA18 titanium alloy pipes

using a method that combines uniaxial tensile testing and finite element simulation. First

the mechanical properties of the pipe were tested to obtain the material performance parameters. The finite element model of the pipeline was established based on various parameters. The corresponding bending die model was established based on the appearance requirements of typical CNC bending parts

and the CNC bending of the pipes was simulated and analyzed. At a 45° bending angle

the effects of friction coefficient

gap and bending speed on the maximum cross-sectional distortion and maximum outer wall thickness reduction of TA18 titanium alloy tube CNC bending forming were studied. Simulation and experimental results show that when the friction coefficient between the bending die and the pipe is increased while decreasing the friction coefficient between the pressure die/anti-wrinkle die and the pipe

combined with a 0.01 mm gap between the pressure die and the pipe

a bending speed of 0.15–0.5 rad/s

a pressure die feed speed of 8–16 mm/s

and an axial feed speed ratio of 1.1–1.2

the forming quality can be significantly improved. Under these conditions

both the maximum outer wall thickness reduction rate and the cross-sectional ovality distortion rate reach optimal values. The study verifies the necessity of parameters collaborative optimization and provides theoretical guidance for practical process parameters setting.