Microstructure evolution and mechanical properties of friction stir welded AA6061/rutile composite

Present study explores the Friction stir welding (FSW) of rutile reinforced AA6061matrix composite using various combination of tool traverse speeds (60, 75 and 90 mm min⁻¹), rotational speeds (750, 1000 and 1250 rpm) and tool pin profiles (Threaded cylindrical and Square profiled pin). FSW process variables have significant impact in controlling the mechanical properties of the joint by limiting the welding defects. It has been inferred from the study that tool rotational speed and tool traverse speed majorly affects the microstructure, joint quality, hardness and joint strength. The weld area showed the presence of four distinct regions usually found in FSW of aluminium matrix composites. The weld region exhibited fine equiaxed grains and uniformly distributed tiny reinforced rutile particles. Tool having square profiled pin shows improved joint properties in comparison with tool having threaded cylindrical pin. (paper)