Effect of FSP’s Rotation Speed on Thermo-Mechanically Affected Zone of AA2024 Alloy

Friction stir processing (FSP) was performed on a 2024 aluminum alloy sheet with a thickness of 2.5 mm. Determination of the parameters affecting on the microstructure is very important to investigate the grain size changes in Thermo-Mechanically Affected Zone (TMAZ). In this study, were investigated the effect of tool rotation speed on the microstructure and mechanical properties of the areas around the stir zone when keeping the traverse speed constant. The average grain size in advancing side were decreased from 6 μ to 3 μ by increasing rotation speed from 315 to 500 rpm and were increased from 3μ to 7μ by increasing rotation speed from 500 to 800 rpm. The average grain size in retreating side were decreased from 7μ to 4μ by increasing rotation speed from 315 to 500 rpm and were increased from 4μ to 8μ by increasing rotation speed from 500 to 800 rpm. Also the advancing side’s grain size was smaller than that of the retreatin side. The mechanical properties of advancing and retreating sides were semillar.