“Influence of Si, Sb and Sr Additions on the Microstructure ...

H Chapter2: Literature Review
Zn-0.7% Zr-1.3% MM), QE22 (Mg-0.7% Zr-2.5% Nd-2.5% Ag) <strong>and</strong> particularly
WE43 (Mg-4% Y—3.25% Nd-0.5% Zr) are commonly used for aircraft applications
due to their improved corrosion <strong>and</strong> creep resistance.
2.3.2 Defense Industries
High specific strength <strong>and</strong> rigidity coupled with ease <strong>of</strong> fabrication are
important for missile <strong>and</strong> space applications. EZ33 (Mg-2.7% Zn-0.7% Zr-3.2% MM)
s<strong>and</strong> castings are used in the “Skylark” research rockets. ZK5l (Mg-4.5% Zn-0.7%
Zr) <strong>and</strong> ZE41 castings have been used extensively for structural parts in British
missiles [57].
2.3.3 Automobile Industries
Automobile industries are the latest beneficiary <strong>of</strong> magnesium, currently
exploring its maximum usage. Table 2.3 gives a number <strong>of</strong> applications <strong>of</strong> magnesium
that are currently being addressed by the automotive industry. Components at the top
<strong>of</strong> this list, such as steering wheel armatures, cylinder head covers <strong>and</strong> instrument
panel beams are already in significant production, while items at the bottom <strong>of</strong> the list
require several years <strong>of</strong> intensive development before they can be implemented [12].
Figure 2.2 gives some <strong>of</strong> the automobile components made from magnesium
alloys [58].
Table 2.2: Advantages <strong>of</strong> magnesium alloys [56]
1. Strength/Weight ratio
i2.ilLiExcellentidamping capacity) A i
l 3. l Non-magnetic, EMF shielding
lGood heatdissipation A A
is. “High castability A A it
6. l Complex, thin walled castings
__- l_. , . .
F 7. l Excellent machinabiltiy
ll