Research on laser welding process and molding effect under energy deviation

In order to further understand the energy deviation characteristics and internal laws in the process of high-power disk laser deep penetration welding, a multisensory fusion system was set up to monitor and analyze the variation of the energy in the different depth of the keyhole. Two different sensing technologies were integrated. The first was photodiode sensing for the monitoring of light radiation which was generated from laser focus position. The second was visual sensing based on auxiliary illumination for the monitoring of the dynamic behavior of the molten pool and metallic plume. The result shows that the large amount of evaporation caused by the preheating effect is one of the reasons for the welding instability. How to effectively control the evaporation is the key to the stabilization of the energy distribution and the improvement of the welding instability. The metallographic microstructure of the cross section has a good match for analysis of the signal.