Effect of Tool Rotation Speed on the Hardness of Welded Joints of Aluminium Alloy(6063) Welded by Friction Stir Welding Process

Aluminum alloys are used in engineering design for their light weight, high strength-to weight ratio, corrosion resistance, and relatively low cost. Aluminum is available in various compositions, including “pure� metal, alloys for casting, and alloys for the manufacture of wrought products wrought Alloys. Most aluminum alloys used for wrought products contain Less than 7 percent of alloying elements. By the regulation of the amount and type of elements added, the properties of the aluminum can be enhanced and its working characteristics improved. In this welding process we have study that two pieces of aluminum alloy (6063) were welded with the help of friction stir welding process and here in this welding process we have found that the microstructure of weld zone was characterized by dynamic recrastallization producing fine grain structure. The vickers hardness testing results obtained for welded specimens and we have observed that the hardness is increases and decreases on different parameters like tool rotation speed. But we have obtained that as the tool rotating speed is increases the hardness will aslo increases. Finally we obtained the max. hardness(Hv-40) on max. Tool rotation speed of (rpm-1800).