On the process parameter of laser tube bending

Laser tube bending is a process in which the laser irradiates the tube surface to induce the thermal stress and bend the tubes. As no hard tooling or external forces is needed during, laser tube bending is a flexible forming process and has potential to deal with materials difficult to bend or thin wall tubes. A formula for bending angle is proposed based on plastic mechanics and verified by experiment. It can be seen that the bending angle is as a result of laser power, laser scanning speed, tube dimension and material properties. For multi pass bending, the bending angle increases with the laser irradiation number but not linearly. The maximum value of laser power, with which the laser will melt the metal during bending, and the minimum, with which the laser can not induces plastic bending, are also proposed.