Abstract
Microstructure changes in dissimilar friction stir welding of 316L and Al 5083 were investigated using electron microscopy techniques. The results showed that there is a refinement of the structure in both base metals.
The change in aluminum structure is governed by a dynamic recrystallization. The low temperatures of the process and the microstructure changes on the structure of the steel allows us to deduce that the grain refinement of the steel is governed by a continuous dynamic recrystallization.
Different intermetallic compound were identified by electron diffraction in the welded region. At the interface, in the steel side of the weld, the studies allowed to identify two Al-Fe intermetallic compounds, namely Al13Fe4 with monoclinic structure and Al5Fe2 with orthorhombic structure.
In the stirred zone, a new intermetallic was observed, in the form of particles identified as α-Al(Fe,Mn)Si with a bcc structure.