Aluminum is the most abundant metal and the third most abundant element in the Earth's crust, after oxygen and silicon. It makes up about 8% of the Earth's solid surface by weight. Aluminum is also chemically reactive and occurs naturally as a free metal (Kobayashi et al, 2002). There are many applications of aluminum in our daily life, such as construction machinery, aircraft construction, shipbuilding, home furnishings and electronic components. For the automotive industry, aluminum has established a global position due to its advantages over other competitive materials, such as light weight, providing exceptional unit strengths (strength to density ratio), high corrosion resistance, low maintenance costs , good temperature resistance (even in arctic environments), ductile, easily joined by all commercial processes such as welding, brazing or soldering, finally, aluminum can be easily formed by all common processes, including extrusion (a large advantage) and can be recycled. Besides advantages, there are some disadvantages of aluminum. First of all, aluminum relatively e.g...