Method and system for laser additive manufacturing based on keyhole effects

A system for laser additive manufacturing based on keyhole effects, comprising:

• a substrate (1), having a surface suitable for additive manufacturing;
• and
• a welding wire (7) and a laser beam (5), arranged at two sides of a normal line of the substrate (1) at certain angles with respect to the normal line respectively,
• wherein the laser beam (5) is applied on the welding wire (7)and produces a deep penetration melting keyhole (4), the welding wire (7) absorbs energy of the laser beam (5) and is heated and melted in a deep penetration melting mode, and the welding wire (7) transits energy to the substrate (1) to form a melting pool (3) and a cladding layer (2) at a first area;
• after passing through the welding wire (7), the laser beam 5 irradiates a second area of the substrate (1) to preheat the second area of the substrate (1) in a thermal conduction mode.