Sep 13 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Introduction
Magnesium is a silvery-white metal which is used as an alloy element for zinc, lead, aluminum, and other nonferrous alloys. Magnesium alloys are light weight and feature superior machinability and ease of casting. They are often anodized to enhance their corrosion resistance property. They are designated using the ASTM and SAE system in which the first part denotes the two main alloying elements in the alloy and the second part represents their percentages.
The following datasheet gives an overview of magnesium AZ61A alloy.
Chemical Composition
The following table shows the chemical composition of magnesium AZ61A alloy.
|
Element |
Content (%) |
|
Magnesium, Mg |
92 |
|
Aluminum, Al |
5.80 - 7.20 |
|
Zinc, Zn |
0.40 - 1.50 |
|
Manganese, Mn |
0.15 |
|
Silicon, Si |
0.10 |
|
Copper, Cu |
0.050 |
|
Nickel, Ni |
0.0050 |
|
Iron, Fe |
0.0050 |
Physical Properties
The physical properties of magnesium AZ61A alloy are given in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
1.80 g/cm3 |
0.0650 lb/in³ |
Mechanical Properties
The mechanical properties of extruded magnesium AZ61A alloy are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
310 MPa |
45000 psi |
|
Yield strength (@ strain 0.200%) |
230 MPa |
33400 psi |
|
Compressive yield strength (at 0.2% offset) |
130 MPa |
18900 psi |
|
Ultimate bearing strength |
470 MPa |
68200 psi |
|
Bearing yield strength |
285 MPa |
41300 psi |
|
Shear strength |
140 MPa |
20300 psi |
|
Shear modulus |
17 GPa |
2470 ksi |
|
Elastic modulus |
44.8 GPa |
6498 ksi |
|
Poisson's ratio |
0.35 |
0.35 |
|
Elongation at break (in 50 mm) |
16% |
16% |
|
Hardness, Brinell (500 kg load, 10 mm ball) |
60 |
60 |
|
Hardness, Knoop (estimated from Brinell) |
80 |
80 |
|
Hardness, Vickers (converted from Brinell hardness) |
68 |
68 |
|
Machinability (relative rating, 100=best) |
100 |
100 |
|
Charpy impact |
4.10 J |
3.02 ft-lb |
Thermal Properties
The thermal properties of magnesium AZ61A alloy are highlighted in the following table.
|
Thermal Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@ 0-100°C/32-212°F) |
26 µm/m°C |
14.4 µin/in°F |
|
Thermal conductivity (estimated from trends in similar Mg alloys) |
70 W/mK |
486 BTU in/hr.ft²°F |
Other Designations
Other designations equivalent to magnesium AZ61A alloy include ASTM A176.