激光功率对高强钢DP780-铝合金5052异种材料焊接的影响

研究激光功率对钢铝异种材料焊接的影响,采用光纤激光器对厚度均为2 mm的高强钢DP780和铝合金5052进行异种材料搭接焊试验。利用高速摄像仪、万能拉伸机、金相显微镜、扫描电镜进行试验,获取焊接过程的图像、接头的抗拉伸强度以及焊缝横截面的显微图,分析激光功率对焊接过程飞溅、焊缝的机械性能和焊缝横截面形貌的影响。结果表明:当焊接功率为2.3 kW时,焊接过程最稳定;当焊接功率为2.5 kW时,焊缝的抗拉伸强度达到最大值35.63 MPa。当激光功率过高时,在界面处生成过多脆性化合物,焊接过程过于不稳定,对焊件的抗拉伸强度造成了不利影响;在激光功率适宜时,可以获得机械性能良好的接头。

Effect of Laser Power on Laser Welding of Steel-Aluminum Dissimilar Metals

In order to research the influence of laser power on the welding of steel-aluminum dissimilar materials,the overlap welding experiments of dissimilar materials for high strength steel DP780 and aluminum alloy 5052 with thickness of 2 mm were carried out by using fiber laser.High-speed camera,universal stretcher,metallographic microscope and scanning electron microscope were used to carry out experiments.The images of welding process,tensile strength of joints and cross-section of welds were obtained.The effects of laser power on the spatter,mechanical properties and cross-section morphology of the welds were studied.The results show that when the welding power is 2.3 kW,the welding process is the most stable;when the welding power is 2.5 kW,the tensile strength of the weld reaches the maximum value of 35.63 MPa.When the laser power is too high,too many intermetallic compounds are formed at the interface,and the welding process is too unstable.It has a negative impact on the tensile strength of the weldment.When the laser power is suitable,the joints with good mechanical properties can be obtained.