MODIFICATION OF MICROSTRUCTURE, MECHANICAL PROPERTIES AND WEAR PERFORMANCE OF 5083 ALUMINUM ALLOY USING FRICTION STIR PROCESSING

Friction Stir Processing (FSP) was applied to as-rolled AA5083 aluminium alloy to enhance its wear resistance through microstructural refinement. Processing was conducted at a tool rotation speed of 1120 rpm and a traverse speed of 40 mm/min. The Peak processing temperature increased with the number of passes, reaching ~492°C after three passes, which, combined with severe plastic deformation, promoted dynamic recrystallization and grain refinement. Orientation maps confirmed progressive refinement in the nugget zone, with average grain size reduced from ~10 μm (one pass) to 4 μm (three passes). This refinement enhanced hardness in line with the Hall–Petch effect. Tribological testing showed that the as-rolled alloy had a wear rate of 6 × 10⁻³ g/min, which rose to 7 × 10⁻³ g/min after one FSP pass due to abrasive particle generation. With additional passes, the wear rate decreased to 5.5 × 10⁻³ g/min and 4.5 × 10⁻³ g/min, demonstrating improved resistance beyond the as-rolled condition. The enhancement is attributed to grain refinement, and higher hardness.