Introduction of a new method for bending of AISI 304L stainless steel micro-tubes with micro-wire mandrel

Abstract The purpose of this study is presenting a new method for bending metal micro-tubes in a critical bending ratio. At first, using the fluid pressure and bending die in the bending ratio of 1.6, the micro-tube has been bent, which is caused wrinkling on the intrados of the micro-tube. Then, using a micro-wire mandrel, a new method for micro-tube bending has been proposed. Two parameters of micro-wire clearance and micro-wire arrangements have been investigated to generalize this method. The results have shown that the clearance of micro-wire with micro-tube should not be less than 50 μm because it will not be possible to insert micro-wire into the micro-tube. Also, the arrangement that has less clearance will have less cross-section distortion because they cause more filling within the micro-tube. In general, the results have shown that micro-tube bending with micro-wire mandrel did not have defects such as wrinkling and rupture. It also allows the micro-tube to bend at room temperature in a critical bending ratio.