Investigation of melting dynamics of filler wire during wire feed laser welding

摘要

In order to investigate the mechanism of stability for the wire feed laser welding process, systematic experiments are carried out in this study for 5A06 aluminum alloy. By using high speed camera, the melting dynamics of filler wires with different feed positions and feed rates are studied. The results indicate that these two factors mainly influence the characteristics of the filler wire melting dynamics and determine the stability of the welding process. The melting dynamics of filler wire can be generally characterized by three different forms: explosion, big droplet and molten metal bridge. When the filler wire melts and transits to the molten pool in the forms of explosion or big droplet, the stability of the welding process is strongly disturbed, resulting in an undesirable weld quality. In contrast, when it is in molten metal bridge form, the welding process is more stable and a uniform weld bead is achieved.