Evaluation of microstructure and wear behavior of friction stir processed cast aluminum alloy

As-cast A356 aluminum alloy processed by friction stir processing at various rotation rates was subjected to microstructural analysis and dry sliding wear tests. Friction stir processing resulted in a significant microstructural modification and improvement in wear behavior of A356. Wear resistance improvement was attributed to significant modification in size, morphology and distribution of Si particles, grain refinement, and hardness enhancement. Furthermore, it was found that higher tool rotation rates were more effective to refine microstructure and consequently increase wear resistance.

► FSP was utilized to modify the microstructure of Cast A356 alloy. ► FSP created a uniform distribution of fine and near spherical Si particles. ► The stirred zone of processed samples contained fine and recrystallized grains. ► These microstructural refinements due to FSP led to wear resistance improvement. ► Higher tool rotation rate was more effective to increase the wear resistance.