Improvement of TIG lap weldability of dissimilar metals of Al and Mg

The technique of tinning on magnesium has been used to improve the tungsten inert gas (TIG) lap weldability of dissimilar alloys of dissimilar metal Al 6061 to Mg AZ31B. The composition at the interface of the samples welded both directly and after tinning on magnesium was mapped by electron probe microstructure analysis (EPMA). Results revealed that tinning on the magnesium plate could eliminate the factors which affect the wet ability at the interface of the samples TIG welded directly. Tinning did not prevent the interaction between Mg and Al to form intermetallic compounds completely, but reduced the intermetallic compounds to some degree.