A number of defects can occur when laser welding aluminium alloys. The defects considered to be most important to try to avoid include porosity, edge effects and instability problems. Edge effects were found to be of different types when welding thin and thick material respectively. Common for both is that the heat distribution in the workpiece determines the result and that it can be theoretically predicted. Instability problems include random blowholes, smoke, spatter and weld depth variations.
Natural variations exist but they can be controlled by the process parameters.
The one most important cause of spatter from the melt is the amount of magnesium as an alloying element. The strength of the welded joints has been tested in static as well as dynamic loading. The conclusion of this work is that welding of aluminium alloys is a challenge. It is predicted that methods such as riveting and clinching in the future in many cases will be replaced by the more cost effective laser welding. Laser welding of aluminium alloys will be increasingly used in automated industry as knowledge of the process continues to grow.