7178 aluminium alloy

7178 aluminum alloy is wrought alloy. It has high zinc content.^[1] After annealing, aluminum alloy 7178 has high machinability.^[2] Resistance welding can be used.^[3]

Chemical composition

The chemical composition of Aluminium / Aluminum 7178 alloy is outlined in the following table. It is difficult to cold work. Forming is hard to use for this alloy. It has high machinability.^[1]

Element[1]	Content (%)
Aluminium / Aluminum, Al	88.1
Zinc, Zn	6.8
Magnesium, Mg	2.7
Copper, Cu	2.0
Chromium, Cr	0.26

Properties

Properties	Metric
Density[1]	2.82 g/cm3
Melting point[1]	482 °C
Elastic modulus[1]	70-80 GPa
Poisson's ratio	0.33
Thermal expansion	23.4 (10-6/°C)
Ultimate Tensile Strength[4]	607 MPa
Tensile Yield Strength[4]	538 MPa

Designations

Aluminium alloy 7178 alloy can be designated as:^[1]

1. ASTM B209
2. ASTM B221
3. ASTM B241
4. ASTM B316
5. QQ A-200/13
6. QQ A-200/14
7. QQ A-250/14
8. QQ A-250/21
9. QQ A-250/28
10. QQ A-430
11. SAE J454

Applications

1. Aircraft components^[1]
2. Petroleum refineries^[5]
3. Boilers^[5]
4. Heat exchangers^[5]
5. Condensers^[5]
6. Pipelines^[5]
7. Cooling towers^[5]
8. Steam exhausts^[5]
9. Electric generation plants^[5]