“…Since laser welding has advantages such as local heat input, short process time and high flexibility compared with other welding processes, there has been considerable research on the welding of steel and aluminum. In the recent, the studies of keyhole welding (Torkamany, et al, 2010), laser welding-brazing (Dharmendra, et al, 2011), dual-beam YAG laser welding (Yan, et al, 2010), and thermal cycle during laser welding (Fan, et al, 2011) are carried out.…”