On the fabrication and characterization of Al5083/Al2O3 surface nanocomposite via friction stir processing

In the present study, Al5083- Al2O3 nanocomposite was successfully prepared by friction stir processing (FSP) with rotational speed of 710 rpm and travel speed of 14 mm/min. In order to improve distribution of Al2O3 particles, a net of holes were designed on the surface of Al5083 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 Al5083- Al2O3 surface nanocomposite. Microstructural observation demonstrated fine and equiaxed grains and homogenous distribution of Al2O3 nanoparticles in the stir zone (SZ). The presence of Al2O3 nanoparticles lead to a decrease in the grain size from 45 to 7 μm and an increase in microhardness from 80 to 140 Hv and tensile strength from 280 to 335 MPa. Wear test results showed improved wear resistance due to its higher hardness and the mode of wear in the all samples was abrasive.