Development of spatter suppression using hybrid laser with blue and IR lasers for welding of pure copper

A hybrid laser system combining a blue diode laser (450 nm) and an IR disk laser (1030 nm) was developed to improve weld stability and reduce spatter generation during pure copper welding. Bead-on-plate welding experiments were conducted on oxygen-free copper plates using varying IR input energies (810–1620 J), with and without blue-laser assistance. High-speed imaging and two-color thermometry were employed to analyze the molten pool dynamics and temperature distribution. The results demonstrated that the hybrid laser system significantly increased molten pool area (by a factor of 3.4), reduced spatter formation by 84%, and improved keyhole stability. The enhanced absorptivity due to preheating by the blue laser helped moderate the sharp temperature-dependent jump in IR absorptivity, thereby stabilizing the heat input and molten pool behavior. These findings suggest that the blue–IR hybrid laser system is an effective solution for high-efficiency and high-quality welding of thick pure copper components, offering strong potential for applications such as busbar joining in electric vehicles.