Friction Stir Processing of Magnesium Alloy with Spiral Tool Path Strategy

Friction stir processing is a relatively new technique for microstructural modification to improve the mechanical properties of materials. Previous works have been primarily focused on the processing of the small regions. The objective of this work is to study the effect of tool design, tool rotation direction and tool overlap between passes on the processed region. A spiral tool path strategy is employed to process the complete blanks of a magnesium alloy. Three tool designs: tool with hexagonal, tapered and threaded pin, are used. Further, tool rotation direction and tool overlap between passes are varied across the experiments. The material flow and defects formed in the processed region are characterized. Preliminary results show that tool rotation direction and tool overlap significantly affect the defects formed in the processed region. The present work identifies the processing condition for defect-free processed region and refined microstructure of the Magnesium blank.