Jul 15 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Applications
Introduction
Magnesium alloys are lightweight materials that are in great demand in the aerospace industry. Today the scope for application has widened. Magnesium alloys contain one of these elements aluminium - zinc, manganese, silicon, copper, rare earths and zirconium, in combination with magnesium.
Magnesium EQ-21A-T6 alloy is similar to magnesium QE22A; however it possesses less silver, thereby lowering the cost. This is a cast alloy with excellent short-time elevated-temperature mechanical properties, pressure tightness, and weldability.
The following datasheet gives an overview of magnesium EQ-21A-T6 alloy.
Chemical Composition
The following table shows the chemical composition of magnesium EQ-21A-T6 alloy.
|
Element |
Content (%) |
|
Magnesium, Mg |
95.7 |
|
Neodymium, Nd |
1.5 - 3 |
|
Silver, Ag |
1.3 - 1.7 |
|
Zirconium, Zr |
0.40 - 1 |
|
Copper, Cu |
0.050 - 0.10 |
|
Nickel, Ni |
≤ 0.010 |
|
Other, total |
≤ 0.30 |
Physical Properties
The physical properties of magnesium EQ-21A-T6 alloy are given in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
1.81 g/cm³ |
0.0654 lb/in³ |
|
Melting point |
540 - 640°C |
1000 - 1180°F |
Mechanical Properties
The mechanical properties of magnesium EQ-21A-T6 alloy are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
234 MPa |
234 psi |
|
Yield strength (@strain 0.200 %) |
193 MPa |
28000 psi |
|
Elastic modulus |
45 GPa |
6530 ksi |
|
Shear modulus |
17 GPa |
2470 ksi |
|
Poisson's ratio |
0.35 |
0.35 |
|
Elongation at break (in 50mm) |
2% |
2.00% |
|
Hardness, Brinell |
65-85 |
65-85 |
Thermal Properties
The thermal properties of magnesium EQ-21A-T6 alloy are highlighted in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@0.000-100°C/ 32-212°F) |
26.7 µm/m°C |
14.8 µin/in°F |
|
Thermal conductivity |
113 W/mK |
784 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to magnesium EQ-21A-T6 alloy are listed below:
-
EN 1753 MC65220
-
AMS 4417
-
ASTM B 80
-
ASTM B 199
-
ASTM B 403
Applications
Magnesium EQ-21A-T6 alloy is chiefly used for industry and military sand and permanent-mold castings used in solution-treated and artificially aged condition (T6-temper) with high yield strengths.