An experimental investigation has been carried out on microstructure and tensile properties of weld b of aluminum alloy. Two different welding processes have been considered: a conventional tungsten inert gas (TIG) process and an innovative solid-state welding process is known as friction stir welding (FSW) process. In this study it has been found that heat affected zone of FSW is narrower than TIG welding and mechanical properties like tensile strength etc. are within comfort zone and are better than TIG welding method. Microstructure results also favour FSW. TIG welding process produces the sound joints but the newly developed method friction stir welding process gives better joints than TIG welding process. The effect of two welding processes on mechanical and metallurgical properties is studied in this research work. Mechanical properties of the welded joints were evaluated and it was found that friction stir welded joints have superior mechanical properties as compared to TIG welded joints. From the microstructure analysis, it was observed that fine and equiaxed grains were observed in the friction stir welded joints and coarse grains were observed in TIG welded joints.