On the fabrication and characterization of Al۵۰۸۳/Al۲O۳ surface nanocomposite via friction stir processing

In the present study, Al۵۰۸۳- Al۲O۳ nanocomposite was successfully prepared by friction stir processing (FSP) with rotational speed of ۷۱۰ rpm and travel speed of ۱۴ mm/min. In order to improve distribution of Al۲O۳ particles, a net of holes were designed on the surface of Al۵۰۸۳ sheet. The samples were characterized by optical and scanning electron microscopy (SEM), microhardness, tensile and wear tests. Results showed that FSP is an effective process to fabricate Al۵۰۸۳- Al۲O۳ surface nanocomposite. Microstructural observation demonstrated fine and equiaxed grains and homogenous distribution of Al۲O۳ nanoparticles in the stir zone (SZ). The presence of Al۲O۳ nanoparticles lead to a decrease in the grain size from ۴۵ to ۷ μm and an increase in microhardness from ۸۰ to ۱۴۰ Hv and tensile strength from ۲۸۰ to ۳۳۵ MPa. Wear test results showed improved wear resistance due to its higher hardness and the mode of wear in the all samples was abrasive.

Keywords:

Friction Stir Processing , Nanocomposite , microhardness , Grain refinement , Wear