Abstract
The aluminium alloys are the most used material in mechanical applications; especially in structural applications. There is potential scope to study aluminium alloys used in aerospace industry. The welding is the main joining process of aluminium alloys. Welding processes are of two types- solid state and liquid state welding. Both types of welding processes have its own advantages and disadvantages. Gas metal arc welding and tungsten metal arc welding are the two popular welding processes that are applied in industry. In solid state welding of aluminium alloys, friction stir welding is getting vast attention. It is defect free welding process as the metal does not reach upto melting point, so less chance to welding defects.