Characteristic features of MIG welding of magnesium alloys

During the last years, great progressions have been made in the fields of w elding power sources and filler materials for the metal inert gas (MIG) wel ding of magnesium alloys. These progressions lead to a better welding proce ss, and, therefore, to a high increase in welding results. A crucial accoun t of the welding process is the energy input into the filler material. Thes e problems result of the physical properties of magnesium (melting point 60 0 degreesC, vaporization point 1100 degreesC). The energy input into the fi ller material has to be regulated in such a way that the wire will melt but not vaporize. For this reason, special characteristics of power sources ha ve been examined. The fatigue strength of the examined magnesium alloys aft er welding under reversed bending stresses reaches 50 % of the strength of the base metal. When the welding seam is worked off, the fatigue strength c an be raised up to 75 % of the base metal.