Understanding of spatter formation in fiber laser welding of 5083 aluminum alloy

3D Multiphysical Modelling of Fluid Dynamics and Mass Transfer in Laser Welding of Dissimilar Materials

“…Due to the role of recoil pressure, the molten pool near the keyhole wall has an upward trend, as shown in Figure 2b. According to the previous study by Hua et al [8,9], when It can be seen in Figure 2b that spatter is formed in the welding process, which may damage the laser equipment due to spatter into the light path and may also affect the welding quality. In essence, laser welding is the process of rapid heating and rapid cooling of the material, so that the weld pool width is relatively small.…”

“…Due to the role of recoil pressure, the molten pool near the keyhole wall has an upward trend, as shown in Figure 2b. According to the previous study by Hua et al [8,9], when the stagnation pressure of the melted metal is higher than the surface pressure, spatter may appear. The shear force and recoil pressure are the driving force of spatter formation, which has been experimentally confirmed (Figure 3).…”

“…The keyhole wall surface is affected by the shear force due to the high-speed movement of the metal vapor plasma, the recoil pressure, and the surface tension, thereby increasing its complexity. Similar to surface tension, the shear force is the tangential force at the gas-liquid interface, the size of which is determined by the velocity of metal vapor plasma inside the keyhole [8,9]. The direction of the recoil pressure is the normal direction of the gas-liquid interface, the size of which is a function of the gas-liquid interface temperature, as shown in Equation (9).…”

“…In addition, the formation of pores was due to the collapse of the keyhole. Recently, Hua et al [8,9] performed a simulation study on the mechanism of spatter formation at full penetration condition. Their results suggested that the shear force generated by the high-speed plasma movement was the main cause of spatter formation, which was in full agreement with the experimental results of Chen et al [10].…”

“…In summary, several researchers have conducted further theoretical studies of the coupling behaviors of keyhole and molten pool in similar metal laser welding [1][2][3][4][5][6][7][8][9][10]; according to simulation methods. However, the numerical analysis of laser welding of dissimilar metal is mainly focused on the study of temperature and heat flow field [10][11][12][13][14][15][16].…”