The mechanism and suppression scheme of laser welding spatter formation

Definition of Splash Defect: Splash in welding refers to the molten metal droplets ejected from the molten pool during the welding process. These droplets may fall on the surrounding working surface, causing roughness and unevenness on the surface, and may also cause loss of molten pool quality, resulting in dents, explosion points, and other defects on the weld surface that affect the mechanical properties of the weld.

Splash in welding refers to the molten metal droplets ejected from the molten pool during the welding process. These droplets may fall on the surrounding working surface, causing roughness and unevenness on the surface, and may also cause loss of molten pool quality, resulting in dents, explosion points, and other defects on the weld surface that affect the mechanical properties of the weld.

Splash classification:

Small splashes: Solidification droplets present at the edge of the weld seam and on the surface of the material, mainly affecting the appearance and having no impact on performance; Generally, the boundary for distinguishing is that the droplet is less than 20% of the weld seam fusion width;

 

Large splatter: There is quality loss, manifested as dents, explosion points, undercuts, etc. on the surface of the weld seam, which can lead to uneven stress and strain, affecting the performance of the weld seam. The main focus is on these types of defects.

Splash occurrence process:

Splash is manifested as the injection of molten metal in the molten pool in a direction roughly perpendicular to the welding liquid surface due to high acceleration. This can be clearly seen in the figure below, where the liquid column rises from the welding melt and decomposes into droplets, forming splashes.