Friction stir welding of dissimilar aluminum alloys 2024-T3 To 6061-T6

The importance of aluminum alloys 2024-T3 and 6061-T6 in the aerospace industrial applications push to use a new technology of joining process. The use of fusion welding process for these alloys with the temper conditions ( T3 , T6 ) are not preferred because of the heat generated from the thermal cycle of the welding. Therefore, solid state nature of friction stir welding (FSW) will be very preferable for joining these dissimilar alloys. In the present study, an evaluation for the effect of process parameters on the microstructure and mechanical properties for dissimilar aluminum alloys 2024-T3 to 6061-T6 joint produced by FSW. The experimental work was carried out in the laboratory of mechanical engineering at Gaziantep University and in BCS Metal Company. In this study, FSW joints of good quality have been successfully fabricated from plates with 3mm thickness, using locally made friction stir tool. Four different rotational speed (600, 800, 1000 and 1200 rpm) and three different tool travel speeds (25, 75, and 100mm/min) were used. Experimental results showed that FSW results in fine and equiaxed grain structure at the nugget zone. Better tensile properties were obtained at rotation speed of 1000rpm and traverse speed of 50mm/min. Joint ductility was comparable to that of the base alloys. Tensile failure is found to occur at locations of lower hardness across the welded joints.