高速重复扫描激光塑料焊接工艺研究

目的 提高PA66塑料的焊缝剪切强度,达到实际生产要求.方法 采用高速扫描振镜对PA66塑料进行扫描激光焊接,分析重复焊接次数对塑料焊缝外观及剪切强度的影响,并且对焊缝截面进行测试,分析工艺参数对焊缝截面的影响规律.通过对工艺参数(激光平均功率、重复焊接次数、焊接速度、离焦量)进行四因素四水平正交实验,得到焊缝剪切强度...

High Speed Repeated Scanning Laser Welding Process for Plastics

The work aims to improve the shear strength of PA66 plastics welds, so as to meet the actual production requirements. The high speed scanning galvanometer was used to carry out scanning laser welding for PA66 plastics. The effects of repeated welding times on the appearance and shear strength of plastic welds were analyzed, and the cross section of welds was tested. Then, the effect of process parameters on cross section was analyzed. Four-factor and four-level orthogonal experiments were carried out to process parameters (laser power, repeated welding times, welding speed and defocus) to obtain the parameter for the maximum shear strength of the welds. The maximum shear strength of welds was 174 MPa, reaching 91% of the parent material strength. The corresponding optimal process parameters were average laser power of 70 W, welding speed of 900 mm/s, defocusing amount of 6 mm, and repeated scanning times of 30 times. The factors affecting the shear strength of the welds were repeated welding times, welding speed, and average laser power in the order of primary to secondary. With high speed repeated scanning welding, the laser energy absorbed by the plastic is low every time, and the welding effect is achieved through the gradual accumulation of heat, which can effectively solve the weld burn caused by impurities in the plastic, and the weld trajectory is more uniform and consistent, which improves the shear strength of the weld and meets the actual production requirements.