Aug 5 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Introduction
Magnesium alloys are mixtures of magnesium with other metals such as zinc, aluminium, manganese, silicon, copper, rare earths and zirconium.
For years, designers have chosen to work with magnesium alloys due to their low density. These alloys also possess good high temperature mechanical properties and good to excellent corrosion resistance.
They are designated using the ASTM and SAE system in which the first part indicates the two main alloying elements in the alloy and the second part represents their percentages. Magnesium ZK21A is a wrought alloy.
The following datasheet gives an overview of magnesium ZK21A alloy.
Chemical Composition
The following table shows the chemical composition of magnesium ZK21A alloy.
|
Element |
Content (%) |
|
Magnesium, Mg |
97 |
|
Zirconium, Zr |
0.65 |
Physical Properties
The physical properties of magnesium ZK21A alloy are given in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
1.80 g/cm³ |
0.0650 lb/in³ |
|
Melting point |
600-635°C |
1110-1180 °F |
Mechanical Properties
The mechanical properties of magnesium ZK21A are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
235-260 MPa |
34100-37700 psi |
|
Yield strength (@strain 0.200 %) |
180-195 MPa |
26100-28300 psi |
|
Elongation at break |
4% |
4% |
Thermal Properties
The thermal properties of magnesium ZK21A alloy are highlighted in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient |
27 µm/m°C |
15 µin/in°F |
|
Thermal conductivity |
125 W/mK |
868 BTU in/hr.ft².°F |