7022 aluminium alloy

A7022 T651
Physical properties
Density (ρ)	2.77 g/cm^3
Mechanical properties
Young's modulus (E)	70 GPa
Tensile strength (σt)	440 MPa (64 ksi)
Elongation (ε) at break	6%
Poisson's ratio (ν)	0.33
Hardness—Rockwell	81 HRB
Thermal properties
Thermal conductivity (k)	165 W/m*K
Linear thermal expansion coefficient (α)	2.35*10^−5 K^−1

7022 aluminium alloy is an alloy in the wrought aluminium-zinc family (7000 or 7xxx series). It is one of the more complex grades in the 7000 series, with at least 87.85% aluminium by weight.

Like most other highly alloyed alloys, 7022 is a high strength alloy, with yield strength of 370 MPa. Designed to be resistant to stress corrosion cracking, it has decent corrosion and oxidation resistance comparable to 7075 aluminium alloy[1] but worse than 7039 aluminium alloy. Good machinability, thermal conductivity and dimensional stability make 7022 alloy a material of choice for plastic injection molds.[2]

7022 alloy can be heat treated to increase tensile strength in expense of workability, with most common grade been T651.

Notes: Alternative names for 7022 alloy are A7022 and AA7022.

Chemical Composition

1. Aluminium: 88.35 to 92.4%
2. Zinc: 4.3 to 5.2%
3. Magnesium: 2.6 to 3.7%
4. Copper: 0.5 to 1.0%
5. Manganese: 0.1 to 0.4%
6. Chromium: 0.1 to 0.3%
7. Silicon: 0.5% max
8. Iron: 0.5% max[3]
9. Titanium: 0.2% max
10. Zirconium: 0.2% max
11. Other: 0.15% max

See also

• Aleris (first maker of A7022)

References

1. General Corrosion Resistance Comparisons of Medium- and High-Strength Aluminum Alloys for DOD Systems Using Laboratory-Based Accelerated Corrosion Methods
2. Sahamit machinery 7022
3. matweb.com 7022 Aluminum Composition Spec

Aluminum alloy table