Microstructure of friction stir welding of aluminium alloy to magnesium alloy

The microstructure of the interface between Al alloy and Mg alloy joined by friction stir welding is characterized using electron microscopy. The intermetallic compound reaction layer has a thickness of about 1 μm and consists mainly of fine-grained Al12Mg17 phase. Further nanosize-grained Al3Mg2 inclusions in close proximity to the Al12Mg17 layer appear in the Al alloy.