May 8 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication
Applications
Introduction
The principal alloying ingredients in aluminium / aluminum alloys include manganese, magnesium, copper, zinc and silicon. The market for aluminium / aluminum and its alloys is huge. About 22 million t is newly manufactured aluminium and 7 million t is recycled aluminium scrap.
Aluminium / aluminum 7020 alloy is a heat treatable wrought alloy. Zinc forms a major part of this alloy.
The following datasheet will provide more details about aluminium / aluminum 7020 alloy.
Chemical Composition
The following table shows the chemical composition of aluminium / aluminum 7020 alloy.
|
Element |
Content (%) |
|
Zinc, Zn |
4-5 |
|
Magnesium, Mg |
1-1.40 |
|
Zirconium, Zr + Titanium, Ti |
0.80 - 0.25 |
|
Iron, Fe |
0.4 |
|
Silicon, Si |
0.35 |
|
Copper, Cu |
0.2 |
|
Chromium, Cr |
0.10 - 0.35 |
|
Zirconium, Zr |
0.080 - 0.20 |
|
Manganese, Mn |
0.050 - 0.50 |
|
Other (each) |
0.05 max |
|
Other (total) |
0.15 max |
|
Aluminum, Al |
Remainder |
Physical Properties
The physical properties of aluminium / aluminum 7020 alloy are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
2.78 g/cm³ |
0.100 lb/in³ |
Mechanical Properties
The mechanical properties of aluminium / aluminum 7020-T6 alloy are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength (@thickness ≤100 mm/≤3.94 in) |
≥ 350 MPa |
≥ 50800 psi |
|
Yield strength (@thickness ≤100 mm/≤3.94 in) |
≥ 280 MPa |
≥ 40600 psi |
|
Elongation at break (@thickness ≤100 mm/≤3.94 in) |
≥ 10% |
≥ 10% |
Thermal Properties
The thermal properties of aluminium / aluminum 7020-T6 alloy are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@20-100°C/68-212°F) |
23.1 µm/m°C |
12.8 µin/in°F |
|
Thermal conductivity |
137 W/mK |
951 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to aluminium / aluminum 7020 alloy are listed below:
-
BS H17
-
BA 733
-
EN AW - AlZn4, 5Mg
-
WS 3.4335
-
Hiduminium-45
-
Alcan GB-D74S
Fabrication
Forming and machining of aluminium / aluminum 7020 alloy is good. Welding, aesthetic anodizing and brazing or soldering is not suitable; however protective anodizing can be performed if required.
Applications
Aluminium / aluminum 7020 alloy is chiefly used in the following areas:
-
Frame manufacture, e.g. motorbike or bicycle frames
-
Military bridges
-
In armored vehicles.