Abstract :
Magnesium alloys are being increasingly used in automotive and aerospace structures. Laser welding is an important joining
method in such applications. There are several kinds of industrial lasers available at present, including the conventional CO2 and
Nd:YAG lasers as well as recently available high power diode lasers. A 1.5 kW diode laser and a 2 kW CO2 laser are used in the
present study for the welding of AZ31 alloys. It is found that different welding modes exist, i.e., keyhole welding with the CO2
laser and conduction welding with both the CO2 and the diode lasers. This paper characterizes welds in both welding modes. The
effect of beam spot size on the weld quality is analyzed. The laser processing parameters are optimized to obtain welds with
minimum defects.
