Solid-state welding processes are ideally suited for welding of aluminum alloys. Because these processes do not involve melting, the issue of weld solidification cracking does not arise. Among the solid-state welding processes, Friction Stir Welding (FSW) is very attractive for welding aluminum alloys. In any process the input parameters play a vital role in determining the output characteristics of the process. How to control the input process parameters is the common problem in any process. In order to overcome this problem, various optimization methods can be applied to define the desired...