On Si Redistribution During Friction Stir Processing of Cast Al-7%Si-0.4%Mg Alloys

The evolution of microstructure, specifically Si eutectic particles, was investigated after friction stir processing of A356 castings with single and multiple passes in this study. Si particles were found to coarsen with each pass. The nearest neighbor distance for Si particles also increased with each FSP pass, indicating that microstructure became more homogeneous after each pass.