Effect of Scroll Pin Profile and Tool Rotational Speed on Mechanical Properties of Submerged Friction Stir Processed AZ31B Magnesium Alloy

In this study, an effort has been made to choose an appropriate tool pin profile and rotational speed for a tool using a submerged friction stir processed hot rolled AZ31B magnesium alloy. A defect free process region was obtained using a novel tool shoulder, which consisted of a scroll. Three tool pin profiles, namely, simple cylindrical, stepped cylindrical and stepped square pin have been used. Tensile properties and fracture behavior revealed defect free friction stir processed specimens. The microstructural studies reveal the possibility of producing a defect free processed region using the stepped square pin tool geometry. The presence of fine recrystallized grains (1.99 µm) and the absence of defects in the processed region lead to higher hardness and superior tensile properties.