Tube Shear Hydro-bending of Titanium Alloys

AbstractA shear hydro-bending process was proposed to form the titanium alloys tubes with small bending radius, which can not be integrally formed by the conventional bending methods. Numerical simulation and experimental research were conducted to investigate effects of internal pressure and feeding ratio on defects, strain state and thickness distribution. The results show that the sound part can be successfully manufactured as the internal pressure ranges from 0.2σs to 0.6σs and the feeding ratio ranges from 1.0 to 1.3, while the defects occur if the internal pressure and the feeding ratio exceed to these scopes. The strain state of the inner and outer sides of the bend are tensile and compressive, and the thicknesses are thinning and thickening, respectively, which is influenced prominently by the internal pressure and the feeding ratio. The strain state of the lateral side is shear and the thickness is generally invariable. It can be conducted that shear hydro-bending method is suitable to manufacture the titanium alloys tube with small bending radius. There is a process window for the internal pressure and the feeding ratio, in which the tubes can be successfully formed without defects