**2. In transportation**

One of the characteristic features of Mg, that makes it most explored in diverse fields, is its low density. With a density of 1.74 g/cc, it is lighter than aluminum, Al (2.7 g/cc). The low density of Mg and its alloys, rendered it to be studied extensively in the transportation industry, viz., automobiles and aerospace.

Traditionally, developments in magnesium alloys have been driven by industries like automobiles and aerospace requirements, for any material which is lightweight to operate with the huge demands of the industries (as in engines, gearbox, or casings of aircraft). The low density, only two-thirds that of aluminum, and dramatic improvements in anti-corrosion performance and mechanical properties in recent years have been attractive to designers to use Mg alloys in aerospace applications [2, 3]. Such alloys/components are now specified on projects like the McDonnell Douglas MD 500 helicopter/B52 Stratofortess (**Figure 3**). There are many applications of alloys of magnesium in aerospace industries [4, 5], gearbox parts in a helicopter (Westland Sea King) and wheels of aircraft, both in ZW3. Magnesium when it is forged, is also used in aircraft engine applications. In the future, magnesium forgings are most likely to be used in higher temperature applications.

Besides the aerospace industry, another industry that has enjoyed the advantage of the low density of Mg is the automotive industry. In the 1920s, magnesium began to appear in the automotive industry. The lightweight metal began to be used in racing cars to add to their competitive edge in MRI153M alloy (Mg-Al-Ca-Sr based alloy).

### **Figure 1.**

*(a) Magnesium powder (b) Burning magnesium wire.*
