管材激光弯曲规律的试验研究

通过实验研究管状件激光弯曲成形的机理以及成型规律。金属管状零件的激光弯曲成形是一种利用激光加热来实现构件的柔性成形技术,其基本原理是利用高能激光束扫描金属管表面,加热区域材料的热膨胀引起材料产生堆积,冷却后,该区域材料沿轴向上的缩短,导致了金属管朝向激光束的弯曲从而最终实现无模具成形。影响金属管状零件激光弯曲成形的工艺参数主要有激光功率、扫描角度、扫描次数、光斑直径和扫描速度。通过实验研究了工艺参数对弯曲角度的影响。在一定取值范围内,增大激光功率,增大扫描角度,增加扫描次数,降低扫描速度均可以使弯曲角度变大;增大光斑直径,弯曲角度会变小。

Experiment investigation on rules of laser tube bending

In this paper the mechanism of the laser bending of tube parts is elaborated.And the bending rules are obtained through the experiment.Laser tube bending is a flexible forming process by which metal tube can be bent without external force.It is generally known that laser bending of tubes is achieved through upsetting mechanism.The scanned region of the tube is heated almost homogeneously in the thickness direction,and undergoes compressive plastic deformation and wall thickening due to restriction on thermal expansion by the surrounding material.The major problem in the study of laser bending is to understand the temperature and stress-strain distribution at different process parameters and scanning paths.The process parameters influencing the laser bending parts of tube mainly include laser power,scanning angle and numbers,facular diameter and scanning speed.With the help of the experiment the respective influence of the five process parameters on the bending angle is studied. Within the range of some fixed value given,the bending angle can be increased by the following means: increasing the laser power,scanning angle and scanning numbers and decreasing the scanning speed.