Friction stir welding of magnesium alloy AZ31B to aluminium alloy 5083

Abstract

A preliminary investigation has been carried out into the application of friction stir welding for joining a magnesium alloy to an aluminium alloy. The work has shown that liquation during the welding process can lead to the formation of a brittle intermetallic at the joint interface. This intermetallic has a microstructure composed of a divorced lamellar eutectic containing Al₁₂Mg₁₇ and magnesium. The formation of this microstructure and its influence on mechanical properties are discussed in terms of solidification theory.