Laser welding method for enhanced weld quality and enhanced surface smoothness

A laser welding method for enhanced weld quality and enhanced surface smoothness, said method comprising steps of:

• a. delivering a high energy and long pulse solid state Nd:
• YAG laser beam in a first pass on a material to be welded;
• b. delivering a Nd:
• YAG laser beam in a second pass with a welding nozzle inclined at an angle from normal of a weld bead and a power density of the laser beam in the second pass is lower than a power density of the laser beam in the first pass;
• such that a peak power density of the first pass is below a peak power density required for evaporation of a surface of the material to be welded without forming a keyhole;
• and
• such that an inclination of the second pass lies in a plane, which does not contain the weld bead and a direction of motion of the second pass is opposite to a direction of motion of the first pass for full depth penetration;
• wherein delivery of the laser beam in the second pass is carried out with the welding nozzle inclined at an angle 20°-45° from normal of the weld bead, and
• wherein the beam of the first pass has a long pulse duration of 1 ms-100 ms.